Mod your Beresford TC-7510

[StanleyB]

Any takers on starting such a topic? Suggestions most welcome.

Stan

[leo]

This would be great Stan, I can see this being a busy one;)

Come on guys, surely somebody here wants to get the ball rolling:eyebrows:

[Filterlab]

Well, I would have thought that you're easily the most qualified person on here mate (along with Stan obviously), so give us your thoughts. :)

[Stratmangler]

I've been intrigued by the Mod 21 since finding out about it, but I'm very loathe to lose my DAC for a (short) while.

Any chance of some details ?

Chris:)

[StanleyB]

Starting with the simple upgrades that do not require opening the DAC:


One of the first things people ask me is what they can do to upgrade the power supply. The one I ship with the TC-7510 is a regulated version that works on anything between 90V to 260V. However, a regulated linear power supply of at least 300mA and not more than 15V off load gives better bass handling ability and a fuller sound.
The Maplin unit at POWER SUPPLY (http://www.maplin.co.uk/Module.aspx?ModuleNo=48517)
is also a good upgrade, and frequently mentioned. It is also on offer right now.

Next question I get asked is about USB. Again, Maplin does a unit that fits between a USB port and the TOSLINK input of the TC-7510. USB ADAPTER (http://www.maplin.co.uk/Module.aspx?ModuleNo=34128).

[leo]

Well, I would have thought that you're easily the most qualified person on here mate (along with Stan obviously), so give us your thoughts. :)

I don't own one mate, just borrowed one from a friend, I can't go probing around in stuff thats not mine

Before recommending anything I prefer to try it out myself to be sure it works before posting anything

[Filterlab]

Just do it and see if he notices. ;)

[leo]

Once this thread starts to get busy, I'd imagine it will:smoking: and things have been tested by others and approved would you like the main mods, tips etc selected and placed into a sticky Stan? it may make things easier to find

[StanleyB]

I've been intrigued by the Mod 21 since finding out about it, but I'm very loathe to lose my DAC for a (short) while.

Any chance of some details ?

Chris:)
I have put a pdf file HERE (http://www.beresford.me/Downloads/Mod21.pdf) with some brief details of the mod.
However, I received an email from someone who has gone a bit further. After he removed the caps, he also removed the JRC4558 opamp sandwiched between them and fitted a LM4562MA instead. Then he did the caps upgrade using some expensive ones sourced from eBay.

Someone else left out the caps close to the RCA output socket (the originals are 100uF if I remember correctly) and soldered wired links from the + side of the caps, directly to the centre pins of the fixed RCA output. That means that the variable output won't work any more, and neither the headphone amp. However, the sound quality makes a respectable leap. The DC blocking is now done by the caps at the AUX input of whatever the DAC is connected to.

[leo]

Hmm, so for the Mod21 are you increasing bandwidth of the op-amp?

[leo]

Op-amp rolling is obviously the easy stuff to try, should also bring noticeable differences to the sound.

LM4562 are very good but need care to get the best out of them, their also not much good at driving capacitive loads

Did you ever try the NE5532 instead of the JRC4558 Stan? I know the 5532 is frowned upon by a lot of people and classed as old tat but they are actually capable of decent results

Of course they don't have the speed,bandwidth, ultra low noise as some of the newer types but they are cheap, DC offset can be higher but used on a single rail with DC blocking caps it shouldn't be a problem

For the more expensive so called Audiophile grade theres AD8620, AD8065, LM4562, OPA2132,OPA2134
All of those should work on a single rail, theres lots more that could be tried too

[Stratmangler]

Starting with the simple upgrades that do not require opening the DAC:


One of the first things people ask me is what they can do to upgrade the power supply. The one I ship with the TC-7510 is a regulated version that works on anything between 90V to 260V. However, a regulated linear power supply of at least 300mA and not more than 15V off load gives better bass handling ability and a fuller sound.
The Maplin unit at POWER SUPPLY (http://www.maplin.co.uk/Module.aspx?ModuleNo=48517)
is also a good upgrade, and frequently mentioned. It is also on offer right now.


I've been using one of the Maplin PSU units for the last year, and it is a very good, inexpensive upgrade.

Would a stiff linear PSU be an improvement over the Maplin unit ?

Thanks for the Mod 21 pdf Stan.

Chris:)

[NRG]

I've been running a 12v ALW on the Beresford DAC for a while and IMO it's made a huge difference to the sound, I bypassed the in-line diode as well. I also replaced the o/p 'lytics with some 100uF BlackGates and junked the bypass ceramics and replaced them with MKS Wima. The input 'lytic to the opamp I replaced with some Nichion Fine Gold caps and I've also replaced the 4558 with an OPA2134. They are little blighters to desolder but I managed it without destroying the PCB tracks.

Not sure if the opamp is an 'improvement' but it does sound different, much more like my Naim CD player which may not be all that surprising as it also used the OPA2134...there are better opamps available but I like the 'tone'.

I've also implemented part of Stan's MOD21 by bypassing R11/R14.

I next want to bypass the 10v reg feeding the opamp and take the ALW 12v straight into it. I also think there may be a benefit by adding a second ALW regulator to feed the critical DAC circuit...

[Ali Tait]

Well I've done part of the mod21 in that I've replaced the caps with Black Gates (Only 20 or so quid from Hificollective) and making solder bridges across the resistors.Has made a big improvement.I also have some opamps to change but haven't got round to doing them yet.I'm still using the stock wall wart so I'll have to get one of the Maplin ones.I'm a bit loath to do much more coz the new ones coming out soon! Look forward to reports on how much of an improvement it is on the current one.

[leo]

Are the ALW's stable driving those big caps on the 7510's DC input Neal?

Good idea supplying the dac and op-amp with better regs, just a shame the ALW's are so big

[StanleyB]

Op-amp rolling is obviously the easy stuff to try, should also bring noticeable differences to the sound.

LM4562 are very good but need care to get the best out of them, their also not much good at driving capacitive loads

Did you ever try the NE5532 instead of the JRC4558 Stan? I know the 5532 is frowned upon by a lot of people and classed as old tat but they are actually capable of decent results

Of course they don't have the speed,bandwidth, ultra low noise as some of the newer types but they are cheap, DC offset can be higher but used on a single rail with DC blocking caps it shouldn't be a problem

For the more expensive so called Audiophile grade theres AD8620, AD8065, LM4562, OPA2132,OPA2134
All of those should work on a single rail, theres lots more that could be tried too

I am using the 5532 in the 7510+. I got little time for people who work out the theory but don't try out a component in the circuit it is intended for. Decades of fault finding and circuit modification has taught me a lot about when to abandon theory and use one's ears instead. A bumble bee can't fly after all according to the theory.

The LM4562 is being used by quite a few people in their modification of the TC-7510. I also know of one guy who uses a double OPA627 on a Brown Dog adapter.

The PCM1716 can also be replaced by the WM8716, but there are two extra track mods that are required in order to get it to work properly. The WM8716 hasn't got the analogue filter built in like the PCM1716.

[StanleyB]

Would a stiff linear PSU be an improvement over the Maplin unit ?

Linear sounds better, and battery sounds best. I used to ship them with a linear PSU, before switching to a switched mode PSU. But I still use the linear PSU on mine.

[StanleyB]

The input 'lytic to the opamp I replaced with some Nichion Fine Gold caps and I've also replaced the 4558 with an OPA2134. They are little blighters to desolder but I managed it without destroying the PCB tracks.
I shall now teach you guys the best way to desolder a suface mount IC.
1. Get a Stanley knife with an absolute spanking new blade.
2. Press down gentle on each IC leg of the IC with the sharp tip of the blade till the blade has cut through the leg. It is important that you press down on the leg! Don't try it any other way.
3. Once you have cut out all the legs, whip the IC out.
4. Use a soldering iron with a flat end on the tip.
5. Rest the tip on each of the cut out leg that is still soldered to the PCB for about 2 to 3 seconds.
6. Now move the solder tip in the direction of where the IC body used to be. This will dislodge the soldered leg. Because there is no soldered component in the area where you just swiped the iron tip towards, the leg will not stick to any adjacent part.
7. If you lift the tip up now, in most cases the leg will still be stuck to the iron and you can then clean it off on a wet sponge.
8. The area from which you just removed the IC should now be cleaned with something like meths or so. Then you can just put the new IC in the same space.
9. Press down on each leg with the flat end of the solder iron tip for about 3 seconds. When you lift the soldering iron tip up the IC leg should now be soldered onto the PCB as if by magic.

Notice that at no time did I mention to use solder to solder anything. All donations are most welcome:).

[Covenant]

I take it Stan that all these mods are totally eclipsed by the 7510+?

[StanleyB]

The 7510+ is not a replacement, but an addition in my line up. Not everyone wants USB or the addition of a more expensive headphone amp section, or wants to do opamp rolling for that matter. And fewer still are using their DAC as a digital preamp. So I don't expect it to be selling just as well as the TC-7510.
I see the 7510+ as a specialized product that would be more of interest to people who want something close to Chord64 like performance at less than £200. The TC-7510 is more aimed at the high-end CDP substitution market, as many a Naim, Linn, and Wadia CDP owner who got a TC-7510 can testify to.

[leo]

I am using the 5532 in the 7510+. I got little time for people who work out the theory but don't try out a component in the circuit it is intended for. Decades of fault finding and circuit modification has taught me a lot about when to abandon theory and use one's ears instead. A bumble bee can't fly after all according to the theory.

The LM4562 is being used by quite a few people in their modification of the TC-7510. I also know of one guy who uses a double OPA627 on a Brown Dog adapter.

The PCM1716 can also be replaced by the WM8716, but there are two extra track mods that are required in order to get it to work properly. The WM8716 hasn't got the analogue filter built in like the PCM1716.

Totally agree! I once modded a cdp, a guy listened to it and said bloody hell! thats great! what op-amps you put in it? I said it uses the supplied NE5532's;) he then pulled a face like he had a shit smear under his nose:lolsign:

I think theres another chip from Wolfson (as well as 8716) thats pin compatible with the PCM1716 too

[leo]

I shall now teach you guys the best way to desolder a suface mount IC.
1. Get a Stanley knife with an absolute spanking new blade.
2. Press down gentle on each IC leg of the IC with the sharp tip of the blade till the blade has cut through the leg. It is important that you press down on the leg! Don't try it any other way.
3. Once you have cut out all the legs, whip the IC out.
4. Use a soldering iron with a flat end on the tip.
5. Rest the tip on each of the cut out leg that is still soldered to the PCB for about 2 to 3 seconds.
6. Now move the solder tip in the direction of where the IC body used to be. This will dislodge the soldered leg. Because there is no soldered component in the area where you just swiped the iron tip towards, the leg will not stick to any adjacent part.
7. If you lift the tip up now, in most cases the leg will still be stuck to the iron and you can then clean it off on a wet sponge.
8. The area from which you just removed the IC should now be cleaned with something like meths or so. Then you can just put the new IC in the same space.
9. Press down on each leg with the flat end of the solder iron tip for about 3 seconds. When you lift the soldering iron tip up the IC leg should now be soldered onto the PCB as if by magic.

Notice that at no time did I mention to use solder to solder anything. All donations are most welcome:).

Nicely written and especially ideal for removing stuff thats been soldered with that lead free solder:eyebrows:

[Mike]

I see the 7510+ as a specialized product that would be more of interest to people who want something close to Chord64 like performance at less than £200.

Now *THAT* should be something interesting indeed!


http://smileys.smileycentral.com/cat/36/36_1_55.gif (http://www.smileycentral.com/?partner=ZSzeb001_ZNxpt431YYGB)


http://www.smileycentral.com/sig.jsp?pc=ZSzeb095&pp=ZNxpt431YYGB (http://smiley.smileycentral.com/download/index.jhtml?partner=ZSzeb095_ZNxpt431YYGB&utm_id=7923)

[StanleyB]

I am not interested in 'me too' product designs. I like pushing the boundaries of the impossible and watch the grins on the faces of the competition turn into long faces. It reminds me of when I designed the first touch screen handset that cost less than £100 and that I stacked up against the then £3000 Lexicon touch screen handset. Harrods ended up selling more than 1000 pieces and Elektopack didn't do too bad with them either. And they told me beforehand that I would never be able to take on a £3K handset:). Cambrdige Audio later sold it as the M1.

[NRG]

Are the ALW's stable driving those big caps on the 7510's DC input Neal?

Good idea supplying the dac and op-amp with better regs, just a shame the ALW's are so big

It appears so Leo, I've not noticed or spotted anything on the 'scope to suggest other wise...those caps could go I suppose...

Yes the ALW's take up space and I'd probably be looking to re-house the DAC or go for a two box design.

[StanleyB]

It appears so Leo, I've not noticed or spotted anything on the 'scope to suggest other wise...those caps could go I suppose...

If you got a set of speakers with 12 inch or larger drivers, try out some bass heavy tunes with and without those caps in circuit.

[leo]

It appears so Leo, I've not noticed or spotted anything on the 'scope to suggest other wise...those caps could go I suppose...

Yes the ALW's take up space and I'd probably be looking to re-house the DAC or go for a two box design.

If the ALW's are stable then I wouldn't worry too much, its just that normally these work better with low capacitance on their output

The ALW's are funny things and sometimes can be picky where you use them

[trailer]

Would there be any benefit in disabling the headphone/pre-amp circuitry if you only use the DAC and the fixed outs?

[leo]

If I had one of these I'd be tempted to take out the headphone amp and fit a circuit in its place that could be used as an alternative output stage, you then have two different outputs
Makes comparing against the standard one easy

[StanleyB]

Would there be any benefit in disabling the headphone/pre-amp circuitry if you only use the DAC and the fixed outs?
I tried that and found that it made a difference. I mentioned this to one of my customers who is also a dedicated modder. This is what he replied:

1) LM4562MA op-amp to replace the NJM4558.

2) Since I don't use the variable output or headphone output, and my amp inputs have blocking caps (pp), I removed the 7510 output blocking caps (CC1, CC2 and the electrolytics) and put in a wire link. I also cut the "R" and "L" wires linking the output to the second board to stop the DC signal getting there.

3) Replaced the switching supply with a linear supply and replace the large DC supply electrolytic caps with high quality low-ESR types.


Stan

[trailer]

I wish I had done electronics at school. I'm not bad at soldering but...............

[StanleyB]

I wish I had done electronics at school. I'm not bad at soldering but...............
Marriage sometimes comes with operating instructions, but not always. Learning to solder is far easier;).

[DSJR]

Marriage sometimes comes with operating instructions, but not always.

Mine didn't............................................ .............................:scratch:

[Marco]

I am not interested in 'me too' product designs. I like pushing the boundaries of the impossible and watch the grins on the faces of the competition turn into long faces.


Hahahahahaha.... You are *so* my type of guy, Stan. I just wish there were more in the industry like you then we might have a lot more interesting kit on the market than there is currently!

Marco.

P.S Leo, you're going a fantastic job of the D.I.Y room. At this rate it will become the reference for all other specialist audio forums of a non 'D.I.Y-first' nature :)

[trailer]

I tried that and found that it made a difference. I mentioned this to one of my customers who is also a dedicated modder. This is what he replied:

1) LM4562MA op-amp to replace the NJM4558.

2) Since I don't use the variable output or headphone output, and my amp inputs have blocking caps (pp), I removed the 7510 output blocking caps (CC1, CC2 and the electrolytics) and put in a wire link. I also cut the "R" and "L" wires linking the output to the second board to stop the DC signal getting there.

3) Replaced the switching supply with a linear supply and replace the large DC supply electrolytic caps with high quality low-ESR types.


Stan

Something like these?

http://cgi.ebay.co.uk/LM4562-LM4562MA-LME49860-AUDIOPHILE-OPAMP-SMT-PAIR_W0QQitemZ280289458268QQcmdZViewItemQQptZUK_Au dioTVElectronics_HomeAudioHiFi_CDPlayerSeparates?h ash=item280289458268&_trksid=p3286.c0.m14&_trkparms=72%3A1301|66%3A2|65%3A12|39%3A1|240%3A13 18

[fault151]

I've replaced the caps with Black Gates (Only 20 or so quid from Hificollective)

Hi guys i new on here. I too am modifying my dac. I just wondered which versions of the Black Gates did you use?

Was it the K series?

[StanleyB]

Something like these?

http://cgi.ebay.co.uk/LM4562-LM4562MA-LME49860-AUDIOPHILE-OPAMP-SMT-PAIR_W0QQitemZ280289458268QQcmdZViewItemQQptZUK_Au dioTVElectronics_HomeAudioHiFi_CDPlayerSeparates?h ash=item280289458268&_trksid=p3286.c0.m14&_trkparms=72%3A1301|66%3A2|65%3A12|39%3A1|240%3A13 18

That's the one.

STan

[Ali Tait]

I used FK's I think,so should be run in by this time next year! :)

[fault151]

Hi Guys,i have just installed the mod21 upgrades my self, god what a job it was. I was telling Stan, firstly i had no sound in the left channel, thought i had screwed it up at first, then i realised my capacitors weren't making contact with the pads. It also didn't help i un-soldered the wrong bloody resistors, what a retard! It was very fiddly trying to solder them back on. Anyway i managed it, got sound in both channels, it's sounding great!

I went with Panasonic FM's in the end. Going to let them run in a little.

[fault151]

Stan is it worth replacing the op amp with the LM4562MA? I happen to have one of these lying around. Does it make much difference,i like the sound of this op amp in other dacs i have messed about with.

[StanleyB]

One thing that some people have an issue with is the case. I found a company and software that can help you to design your own case. The software is fee of charge, and the company uses your drawing to make the new case. See
http://www.frontpanelexpress.com/

If any of you decide to embark on that venture, please post the case file you designed.

Stan

[Beechwoods]

Excellent link! Thank you :)

[Tony Moore]

This is the US division (I guess) of Schaeffer who I got both my CD player case parts made, plus my DAC case.

http://i296.photobucket.com/albums/mm168/TonyMoore300B/CDPro2.jpg

http://i296.photobucket.com/albums/mm168/TonyMoore300B/DACOutside.jpg

Excellent company, great service. The software is good, all design is done with their cad package, then you just enter you delivery address and payment details and click the button and a week later you get your parts, all laminated onto cardboard! I bought from Schaeffer in Germany but I guess the site Stan linked to is the equivalent in the US.

Cheers,
Tony

[trailer]

Is anyone using anything like the Theta TLC or the Trichord Pulsemaster before the Beresford?

[Ali Tait]

Would this be necessary? I was under the impression Stan's DAC reclocks the signal on it's own.

[StanleyB]

I was under the impression Stan's DAC reclocks the signal on it's own.
Spot on. And in the USB DAC the USB is also reclocked by its own separate clock so that... ahem.

Stan

[trailer]

That saves me rummaging in the garage then. I've got an old TLC in a box somewhere.

Stan, I was looking at the pfm reply to the PSU and see you recommend running the Maplin PSU at 13.5v. Any reason for this? I have mine running at 12v?

[Ali Tait]

Not tried it myself yet,but peeps have said the DAC sounds better at the slightly higher voltage.

[Stratmangler]

Not tried it myself yet,but peeps have said the DAC sounds better at the slightly higher voltage.

I have preferred mine run at 13.5 vdc .

Got around to doing the Mod21 yesterday afternoon - I'm soak running the DAC at the moment, but when things settle down I'll give 12 vdc another go and see which one I prefer.

Chris:)

[Ali Tait]

Did you change the opamp Chris?

[Stratmangler]

Nah !

Just the caps and solder bridges as per the pdf.

Thought about changing the caps on the mains input, but I'll have to dig around to see what will fit snugly on the pcb and still fit in the case with the top on.

Initial thoughts on the mod are very favourable, but the new caps will take time to settle, so I'll let things run for a while before I post any comments

Chris:)

[Ali Tait]

Yep me too-put Black Gates in,so it might take a while! Have some opamps to put in when I get the chance.

[kalozois100]

hi there , i have ordered parts from uk - for mod 21 and for replacing op amp same as the one you mention. did you change the opamp and if so did you notice any improvements? Thanks

[kalozois100]

I use a belkin pure av power supply into which i plug what i received with the beresford. Would i still benefit from the maplin power supply?

[Stratmangler]

I use a belkin pure av power supply into which i plug what i received with the beresford. Would i still benefit from the maplin power supply?

Yes.

Chris:)

[StanleyB]

I made contact with someone in the UK who has a linear power supply in stock that looks like a good one. The plug is a different size however. He is sending me a sample to test and if it does the bizz I shall try to sort out a deal with him for a small quantity that I can then offer to anyone interested.

Stan

[Stratmangler]

They don't happen to do a 5vdc linear ps too do they ? I'm thinking of Squeezebox here.

Chris:eyebrows:

[StanleyB]

Dunno. I shall ask.

STan

[Stratmangler]

Thanks Stan.

Chris:)

[NRG]

Completed the 12v and 5v mod I've been chewing on this evening.

The 12v input from the ALW superreg now goes directly to the opamp bypassing the 10v reg and I've added a 5v ALW superreg to power the critical digital ccts bypassing the on-board 5v reg. The onboard regs I've left in place to power whatever else they are connected to...no time to listen but I will report back when I get a chance.

[StanleyB]

Have a go at replacing C5 and C6 next to the 4558 for a WIMA 220pF/63V type, or something similar. And of course swap the 4558 over for a LM4562MA or so. Now sit back and enjoy Mod21PT2:eyebrows:. I left those out from my upgrade since they add extra costs and then takes the low price of the TC-7510 a bit higher. That's not the plan.

STan

[kalozois100]

I made contact with someone in the UK who has a linear power supply in stock that looks like a good one. The plug is a different size however. He is sending me a sample to test and if it does the bizz I shall try to sort out a deal with him for a small quantity that I can then offer to anyone interested.

Stan

hello Stan. Please let us know as soon as you have the new power supply available. I ll wait for yours instead of buying the maplin one. And dont worry about the cost of upgrades thats our job.

[NRG]

Have a go at replacing C5 and C6 next to the 4558 for a WIMA 220pF/63V type, or something similar. And of course swap the 4558 over for a LM4562MA or so. Now sit back and enjoy Mod21PT2:eyebrows:. I left those out from my upgrade since they add extra costs and then takes the low price of the TC-7510 a bit higher. That's not the plan.

STan

Stan did you mean C4 /C5? I've already replaced those with nichicon fine gold caps and the opamp I use is an OPA2134 at the moment.

[StanleyB]

Stan did you mean C4 /C5? I've already replaced those with nichicon fine gold caps and the opamp I use is an OPA2134 at the moment.
See http://www.beresford.me/Downloads/Mod21pt2.pdf

[NRG]

Ah! Gotcha, I was looking at EC4/5 :doh:

[StanleyB]

Better late than never:).

[leo]

Looks to be cap across op-amps FB resistor, a nice low inductance polypropylene film and foil should be better than a metalized polypropylene, lots of choices in 5mm spacing

Evox PFR are nice caps, would just require bending the legs in a bit

What about changing MC1 and MC2 filtering for a film cap too?

If changing op-amp to the faster LM4562 what about trying a lytic parallel across C7 ceramic for the decoupling? something like a panny FM or a BG for those that like those

Good thing with modding is that its easy to revert back if you don't like the results:)

[NRG]

Good idea Leo, I'll add that to the list ;)

Snatched a quick listen this morning before rushing out....the ALW 5v reg and 12v into the opamp certainly made a difference....typical ALW effect, HF edge gone, smoother more refined presentation with gains in resolving low level detail and good gains all 'round but low level bass was AWOL!

From past experience the ALW regs run in after a while and the DAC takes a few hours to warm through....

...so back this afternoon and I'm listening again as I type this and after 7hrs running it's sounding very good, bass is coming back and all the refinement noted before is still there if not more so...

There's lot of mileage in this DAC, thanks Stan! I'll try to post pic of my bodging later....

[kalozois100]

Looks to be cap across op-amps FB resistor, a nice low inductance polypropylene film and foil should be better than a metalized polypropylene, lots of choices in 5mm spacing

Evox PFR are nice caps, would just require bending the legs in a bit

What about changing MC1 and MC2 filtering for a film cap too?

If changing op-amp to the faster LM4562 what about trying a lytic parallel across C7 ceramic for the decoupling? something like a panny FM or a BG for those that like those

Good thing with modding is that its easy to revert back if you don't like the results:)

My new found friends i am overwhelmed by all the tech talk. i did a level physics with little electronics so i am envious of your abilities to modify. I have a friend thats an elec. engineer in the army and he is going to do the mods for me. if it we not for Stans pdf`s how on earth could i explain the mods in greek to my friend!!!! thanks again Stan for us not so bright peeps out there when it comes to electronics but share the same passion for listening to music.

[leo]

The TC-7510 is a nice little dac, I don't own one personally but have heard it.
Beauty is its well designed and sounds good as is and also has the potential for those into a spot of diy for shoving its performance further

If this dac is one of your first attempts at tweaking just take your time, don't try too much at once, give things chance to bed in before judging anything;)
Simply post on here if theres anything your not sure of, it shouldn't be too long until somebody comes along with help and advice

[leo]

Another few idea's

The decoupling cap for the CS8414 analogue and digital supply pins, might be worth trying say a Oscon or similar polymer based cap for the digital pin (VD+) and one of your favourite caps for the analogue pin (VA+)
Its surprising how much effect the receiver has on the sound

May also be worth trying an oscon on the multiplexer chips supply pin (VDD)

For the PCM1716 dac chip look at the caps on pins 11 and 18, these seem to be the voltage reference point for the feedback loop of the chips internal op-amp
Might be worth experimenting there

A note regarding the LM4562, you may get varying results with it depending on interconnect lead lengths, type of amp or pre-amp being used, these chips don't drive capacitive loads too well, its a good op-amp but won't be ideal for everybody
This is not to put people off using it BTW :)

[kalozois100]

Another few idea's

The decoupling cap for the CS8414 analogue and digital supply pins, might be worth trying say a Oscon or similar polymer based cap for the digital pin (VD+) and one of your favourite caps for the analogue pin (VA+)
Its surprising how much effect the receiver has on the sound

May also be worth trying an oscon on the multiplexer chips supply pin (VDD)

For the PCM1716 dac chip look at the caps on pins 11 and 18, these seem to be the voltage reference point for the feedback loop of the chips internal op-amp
Might be worth experimenting there

A note regarding the LM4562, you may get varying results with it depending on interconnect lead lengths, type of amp or pre-amp being used, these chips don't drive capacitive loads too well, its a good op-amp but won't be ideal for everybody
This is not to put people off using it BTW :)

a pdf would be very helpful . :doh:

[leo]

If I get one of these dacs sometime I'll try various mods and post some results, pics etc
For now I can only post a few idea's maybe worth trying

Do the tweaks Stan added in the pdf first and see how you go;)

[kalozois100]

If I get one of these dacs sometime I'll try various mods and post some results, pics etc
For now I can only post a few idea's maybe worth trying

Do the tweaks Stan added in the pdf first and see how you go;)
Hello Leo
yes will do so. If i had two tc7510 i d send one to you and let you loose on it . :eyebrows: at moment waiting for mod 21 , LM4562MA opamp replacement and the maplin power supply. :confused:
i have read around that mains power supply leads can make a big improvement such as the one mentioned in what hifi awards. also fuses for the plug. any views on this?:scratch:

[kalozois100]

If I get one of these dacs sometime I'll try various mods and post some results, pics etc
For now I can only post a few idea's maybe worth trying

Do the tweaks Stan added in the pdf first and see how you go;)


p.s.Leo this is the one i was thinking about.


http://whathifi.com/Review/Clearer-Audio-Copper-Line-Alpha-mains/

[StanleyB]

Don't get too carried away with external products that you feel might improve the sound of the DAC. My aim has always been towards trying to keep the changes internal since that is still the cheapest route.
There are loads more mods that can be done to the PCB, but many of them require extreme skills. Like swapping the PCM1716E for a WM8716. The two chips are pin for pin compatible, but the WM8716 has not got an analogue filter circuit built in, whilst the PCM1716 does. So to do that mod requires a few other associated mods. Then there is the CS8414 timing mod for reduced jitter. Etc. etc.

stan

[kalozois100]

Don't get too carried away with external products that you feel might improve the sound of the DAC. My aim has always been towards trying to keep the changes internal since that is still the cheapest route.
There are loads more mods that can be done to the PCB, but many of them require extreme skills. Like swapping the PCM1716E for a WM8716. The two chips are pin for pin compatible, but the WM8716 has not got an analogue filter circuit built in, whilst the PCM1716 does. So to do that mod requires a few other associated mods. Then there is the CS8414 timing mod for reduced jitter. Etc. etc.

stan

i think there would be a market for the modifications you mention if it was offered as an option on your web site. eg say the tc7510 6/4 plus say 100 to150 euro upgrades. i would certainly have appreciated the option when i purchaged it before.
Anyway i am only upgrading with avenues you approve of Stan.
Thanks for your feedback
kalozois

[NRG]

Don't get too carried away with external products that you feel might improve the sound of the DAC. My aim has always been towards trying to keep the changes internal since that is still the cheapest route.
There are loads more mods that can be done to the PCB, but many of them require extreme skills. Like swapping the PCM1716E for a WM8716. The two chips are pin for pin compatible, but the WM8716 has not got an analogue filter circuit built in, whilst the PCM1716 does. So to do that mod requires a few other associated mods. Then there is the CS8414 timing mod for reduced jitter. Etc. etc.

stan

Stan, I'd be interested to learn more about these mods.

Update:
I ran my DAC continuously for 24hrs with the new 5v ALW reg and the sound has now settled IMO. I was still not happy with the low bass quality and went back to the original configuration as a sanity check...what I discovered is that the small (11R ?) surface mount resistor in line to the supply of the opamp is needed, feeding the 12v from the ALW reg via this resistor fixed the low bass.....I have no idea why but without it there was something missing...with it everything fell into place.

I also tried listening without the input PSU caps as you suggested, I didn't loose any bass but I found the sound stage became confused and muddled....very strange. I then tried a single 4700uF Blackgate as a replacement and I was taken aback...

What a difference this made, simply more of everything, I highly recommend to anybody replacing the two PSU caps with a good quality replacement it made a very noticable improvment in my system.

[Jag.Crusher]

Apologies if this question has been asked before :o but...

Is there any way to tell how old - or what mark/version - a Beresford 7510 is by its external appearance or possibly serial number?

Many thanks!
Steve

[leo]

I was thinking, after we get a good collection of tried and proven tweaks on here it maybe worth doing a Wiki , should make things easier to find for those wanting a bash.
Anyway lets see how things go

[leo]

Stan, I'd be interested to learn more about these mods.

Update:
I ran my DAC continuously for 24hrs with the new 5v ALW reg and the sound has now settled IMO. I was still not happy with the low bass quality and went back to the original configuration as a sanity check...what I discovered is that the small (11R ?) surface mount resistor in line to the supply of the opamp is needed, feeding the 12v from the ALW reg via this resistor fixed the low bass.....I have no idea why but without it there was something missing...with it everything fell into place.

I also tried listening without the input PSU caps as you suggested, I didn't loose any bass but I found the sound stage became confused and muddled....very strange. I then tried a single 4700uF Blackgate as a replacement and I was taken aback...

What a difference this made, simply more of everything, I highly recommend to anybody replacing the two PSU caps with a good quality replacement it made a very noticable improvment in my system.

Not knowing all the innards of this dac what other caps are after this 11R resistor Neil? is it just the SMD ceramic for the op-amp +v ? I wonder if it was some too low impedance or something the ALW didn't like and the 11R helps isolate it, also adds more impedance? I do know the ALW's can be picky whats on their output.
The ears are a good test tool for telling you theres a problem

[kalozois100]

Don't get too carried away with external products that you feel might improve the sound of the DAC. My aim has always been towards trying to keep the changes internal since that is still the cheapest route.
There are loads more mods that can be done to the PCB, but many of them require extreme skills. Like swapping the PCM1716E for a WM8716. The two chips are pin for pin compatible, but the WM8716 has not got an analogue filter circuit built in, whilst the PCM1716 does. So to do that mod requires a few other associated mods. Then there is the CS8414 timing mod for reduced jitter. Etc. etc.

stan

Hi Stan .
Can you tell us what the pico seconds are for jitter for the tc-7510 and if this value makes a difference to the transport you can use with it. :scratch:

[StanleyB]

what I discovered is that the small (11R ?) surface mount resistor in line to the supply of the opamp is needed, feeding the 12v from the ALW reg via this resistor fixed the low bass.....I have no idea why but without it there was something missing...with it everything fell into place.
That will teach you wondering why I put it there:eyebrows:.


I also tried listening without the input PSU caps as you suggested, I didn't loose any bass but I found the sound stage became confused and muddled....very strange. I then tried a single 4700uF Blackgate as a replacement and I was taken aback...

You can use a 10000uF/16V, but be careful! There are two Hamei branded ones on eBay that I have tried. The one that is 25mm high is the one to choose. The 30mm version is too high to fit in the case. This cap is part of the Virtual DC power supply design I came up with, which relies on a double regulated power supply chain. The MK6 version was in its experimental stage. In the TC-7520 I managed to make some additional improvements.

Stan

[StanleyB]

Not knowing all the innards of this dac what other caps are after this 11R resistor Neil? is it just the SMD ceramic for the op-amp +v ? I wonder if it was some too low impedance or something the ALW didn't like and the 11R helps isolate it, also adds more impedance?
It's part of my Virtual DC circuit. Since I can't patent it, I can't tell you how it works;).

STan

[leo]

It's part of my Virtual DC circuit. Since I can't patent it, I can't tell you how it works;).

STan

I wouldn't expect that Stan, I know how picky the ALW's can be so mainly wanted an idea what caps they would be seeing on the output, its not unusual for them to oscillate with low ESR types

[kalozois100]

Hi Stan .
Can you tell us what the pico seconds are for jitter for the tc-7510 and if this value makes a difference to the transport you can use with it. :scratch:

i found out the jitter is less than 50 pico seconds if anyone is interested.

[NRG]

That will teach you wondering why I put it there:eyebrows:.


You can use a 10000uF/16V, but be careful! There are two Hamei branded ones on eBay that I have tried. The one that is 25mm high is the one to choose. The 30mm version is too high to fit in the case. This cap is part of the Virtual DC power supply design I came up with, which relies on a double regulated power supply chain. The MK6 version was in its experimental stage. In the TC-7520 I managed to make some additional improvements.

Stan

Thanks Stan! I take it the 11R provides some supply damping / decoupling of the LC cct formed by the PCB track and supply pin decoupling cap. Anyway it works.

I've made futher progress over the weekend, I've reinstated R11/R14. With all of my changes to the PSU I found the sound just little too strident and bright over longer listening, putting them back in has calmed things down. I think I'll try some more opamps as suggested previously.

[leo]

Normally lowering the value of an op-amps FB resistors widens bandwidth, going by the pic it seems R11/14 are in the FB in series with R18/19

[StanleyB]

R11/R14 are part of a MFB filter. You can try lower values like 2K2, but don't leave them out otherwise the filter won't work as it should...

Stan

[kalozois100]

Hello Stan.
Today i recieved the LM4562MA opamp so i took the tc-7510 to elec. engineer and he is going to proceed with changing the opamp along with the mod21 part 1+2. I am really looking forward to the upgrades thanks for providing them in pdf form.
Kalozois.:):):)

[Stratmangler]

After 2 weeks worth of run in (as things have now stabilised) I feel that I am now in a position to comment on the MOD21 part 1 I performed on my 7510 6/3.

I am gobsmacked by the level of detail retrieval at hand - fine detail is rendered with much, much finer brushstrokes.

And yet this greater detailing is not at the expense of tonal balance - the tonal balance is pretty much the same as it was before effecting the MOD21 stuff.

Rhythmically things are bang on the money too (as they were before).

Low bitrate radio streams sound far more convincing than before - I use the BBC iPlayer plugin on with my Squeezebox SB3 setup, and the listen live on Radio 2 sounds very. very good indeed - you're talking 96 kbs with these streams. Any lower on the bitrate and things sound pretty awful, as one would expect (don't bother with Alien BBC unless you have to).

Recordings that are less than perfectly done benefit too - I played "wind up working in a gas station (Zoot Allures)" by Frank Zappa last night, and the track, which is a bit of a production nightmare (ie trashy and thrashy), was more coherent and together than I have previously heard by quite a large margin.

Of course there are some recordings that are beyond redemption, due in no small part to the "loudness wars" that are currently going on, and these still sound like a bag-o-sh*te, but you cannot blame the messenger for this - after all, you can't polish a turd !

All in all, the first stage MOD21 is the best £1.00 (factoring in the cost of running the soldering iron) I've spent on audio upgrades.

And I've ended up turning down the vdc on my Maplin psu back to 12vdc - on the 13.5 vdc setting I felt that the effect was indeed like pressing the loudness button, whereas I felt that it was required with the 7510 6/3 stock unit.

Chris:)

[StanleyB]

All in all, the first stage MOD21 is the best £1.00 (factoring in the cost of running the soldering iron) I've spent on audio upgrades.

It's a pity that so few people would be able to fit the upgrade, since it requires a decent level of electronic repair/hobbyist experience. And one can spend money on far more expensive parts if pocket conditions allow, instead of having to pay P&P and for my time to get it done.
Have to also done the Mod21pt2? The link is mentioned in this thread somewhere. If you are already happy and overjoyed with part1, then you can quite happily skip part2.

Stan

[kalozois100]

It's a pity that so few people would be able to fit the upgrade, since it requires a decent level of electronic repair/hobbyist experience. And one can spend money on far more expensive parts if pocket conditions allow, instead of having to pay P&P and for my time to get it done.
Have to also done the Mod21pt2? The link is mentioned in this thread somewhere. If you are already happy and overjoyed with part1, then you can quite happily skip part2.

Stan

Hi folks!!!!!!!! :eyebrows:
I got in touch with Stan to clarify what capacitors to use in the Mod 21 part 2. It is as follows..........
" Use some wimb type design smd capacitor 220gf of 100v. They are about 8mm high"
I hope others find this as useful as I did. Thanks Stan . Your after sales support is amazing and many a retail shop would do well to follow your good example. I was most impressed that you suggested other dac makes to readers depending upon their needs, showing virtue and respect for your competition rather than dismissing or slagging them off .........a rare character quality these days.......... In my eyes your no longer just Stan but "" Stan the main man":gig:

[StanleyB]

" Use some wimb type design smd capacitor 220gf of 100v. They are about 8mm high"

It should read: use something like Wima 220pF/100V.

STan

[kalozois100]

:doh:Thanks Stan.. I m not an electronics man:scratch: Are you sure they are about 8mm or are they smaller?

[kalozois100]

Hey Stan,
A friend of mine suggested I change the fuses in the power plugs of my seperates according to the power consumption of all the seperates . I thought this odd at first but then having an open mind i tried it. From 13 amp fuses we changed to 3 amp fuses for LP12(has 8 watt power consumption) and amplifier(has 300 watt power consumption). When i listened to the sound system again I was amazed to hear an improvement in the sound. The bass was richer the mids smoother and treble more silky. it was as if the system had already been warmed up for an hour or so. Cant say with tc-7510 cause its at the electrician for modifications. Is there anything in this? Is what ive done safe or am i gonna blow everything up?:scratch: Its the cheapest upgrade i ve made so far - only 1 euro!!!:scratch:

[NRG]

The fuse only really protects the mains lead, the equipment fuse would blow long before the mains fuse. Maybe you noted a difference because the replacement fuse was new and therefore had clean contacts...not an unheard of effect...

I implemented partII of Stans MOD21 today and can vouch for its effectiveness. The LM4562 is much more open and natural than the OPA2134 I was using previously. It's taken the DAC up yet another level, well worth it IMO.

[kalozois100]

The fuse only really protects the mains lead, the equipment fuse would blow long before the mains fuse. Maybe you noted a difference because the replacement fuse was new and therefore had clean contacts...not an unheard of effect...

I implemented partII of Stans MOD21 today and can vouch for its effectiveness. The LM4562 is much more open and natural than the OPA2134 I was using previously. It's taken the DAC up yet another level, well worth it IMO.
Good evening( sorry don't know yor name)
Yes that makes sense. i have been advised to change fuses every 6 to 12 months because they deteriorate.
Ah at last someone who has gone where I'm heading!! :) I'm really happy with your feedback but makes the waiting to get it back harder. My elec. engineer was asking about the mod 21 part 2. Is the C5 and C6 replacements really 8mm high or is it 0.8mm high?what height capacitors did you put in?:scratch:

[trailer]

Is it too soon to open a 7520 mod thread?

[NRG]

I raided my spares box and put in some old polystyrene caps I had, they are not ideal but are OK for now. One like these:

http://uk.farnell.com/lcr-components/fsc-160v-220pf-2-5/capacitor-220pf-160v/dp/9520031

I think Stan was talking about these types though:

http://uk.farnell.com/wima/fkp2-220pf-5-100v/capacitor-220pf-100v/dp/1005983

About 11mm high including the leads.

There are some SMD types available as well:

http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=UF1HZJNZ1AM4WCQLCIQJKBQ?N=10 00229+247545&_requestid=649024

--Neal

[kalozois100]

I raided my spares box and put in some old polystyrene caps I had, they are not ideal but are OK for now. One like these:

http://uk.farnell.com/lcr-components/fsc-160v-220pf-2-5/capacitor-220pf-160v/dp/9520031

I think Stan was talking about these types though:

http://uk.farnell.com/wima/fkp2-220pf-5-100v/capacitor-220pf-100v/dp/1005983

About 11mm high including the leads.

There are some SMD types available as well:

http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=UF1HZJNZ1AM4WCQLCIQJKBQ?N=10 00229+247545&_requestid=649024

--Neal

Thanks Neal.

If elec. engineer doesnt have in stock i ll order from u.k.:)

[kalozois100]

Any ideas where I can get black gate capacitors, for the mod 21 part one, and that they post internationally – I cant find any on ebay. Apparently they are the best to use, or, will any make do the job just as well?
Thanks :scratch:

[Ali Tait]

Try Hi-Fi Collective.I think they will post abroad.

[NRG]

or percyaudio.com or partsconnexion.com..

--Neal

[kalozois100]

Thanks to all,

The mod 21 part 1 is completed. Have replaced op amp in the part 2 but not the caps because I have had to order from uk. Can I use the tc-7510 as it is until I replace the caps or do I have to wait until all the mod is completed?

p.s. Is the snow as bad as they say over there?? its 22 degress in Cyprus :smoking:( i dont smoke but i like the shades. can we have a non smoking smiley with shades please?).

[trailer]

p.s. Is the snow as bad as they say over there?? its 22 degress in Cyprus :smoking:( i dont smoke but i like the shades. can we have a non smoking smiley with shades please?).

No, its media hysteria. As per.

[NRG]

Thanks to all,

The mod 21 part 1 is completed. Have replaced op amp in the part 2 but not the caps because I have had to order from uk. Can I use the tc-7510 as it is until I replace the caps or do I have to wait until all the mod is completed?



Go-ahead and use it, see how it sounds then replace the caps and see what difference there is....all part of the fun!

--Neal

[trailer]

Would the MOD21 upgrade be applicable to the 7520?

i.e. opamp to the LM4562 and the caps to Blackgates etc?

[Ali Tait]

I'm sure Stan will reply,but AFAIK,no,the output stage is different so MOD 21 does not apply.

[StanleyB]

Would the MOD21 upgrade be applicable to the 7520?

i.e. opamp to the LM4562 and the caps to Blackgates etc?

Nope.

STan

[trailer]

Thanks. What are the potential upgrades if any?

[kalozois100]

Go-ahead and use it, see how it sounds then replace the caps and see what difference there is....all part of the fun!

--Neal

Good evening to all!!:)
Well I got back the tc-7510 that is now upgraded from 6/3 to 6/4 (mod 21 part 1 and have replaced op amp in part 2 but because I have had to order the caps from the u.k. the later is still to be done. So far the cost of upgrade is as follows:
Mod part 1:
1) Free. The elec. engineer friend had parts in stock.

Mod part 2
2)15 Euro for opamp LM4562MA (sold as pack of two)
3) 5 euro for 2x Capacitor High Rise 220pf 63v 1%7mm SUF710 ref 2401 that will be fitted shortly.
4) no cost for elec. engineer ( a close friend and has done it cause he owes me many a favour!)

Extra expense:
5) 53 euro for maplin switched mode ac to dc adaptor for general use.

All above inc. cost of shipping to Cyprus.

FIRST IMPRESSIONS (please note I am comparing to 6/3 version specifically and not any other dac or cd player. The tracks mentioned below have been heard before and I took notes since I do not have two tc-7510, a 6/3 and 6/4 to compare at same time. Also go easy on me as I have not done this before and have no qualifications to audition hifi components. Phew got that out of the way)

I played straight away after connecting up. The first listening was track greensleeves (shji Yokouchi Trio & 1) a three blind mice recording. WOW! I couldnt believe my ears. Very smooth and detailed presence remarkable imaging, tighter bass, very clear mids but it is the highs that really impressed me. the build up and pace in this piece of music was all over the place with the 6/3 but now every rhythum was controlled and co-ordinated but with a touch of finesse. Each instrument was clearly heard especially the the drum section - the cymbals caused an emotional tingle that was abscent before.
I wanted to investigate the warmth perspective so the next track was the theme from Harry's game from clannads greatest hits. As soon as the vocals emerged i got goose pimples. Again impressive clarity, imaging, detail and warmth. The fatigue factor present in the 6/3 was gone, deceased. I felt now that with this new level of sound I could quite literally listen for hours whereas the 6/3 got tiring after an hour and a half. I heard clannard live and the 6/4 reminded me of that experience strongly compared to the 6/3.
Next was Chris Rea's road to hell track. Yet again consistant was the 6/4 to offer me warmth, imaging ,detail and clarity but an aditional twist was the sound stage presence. when the tempo increased i was happily shocked to still hear the vocals and instruments defined whereas the 6/3 lost the pace and at time the bass was wild the treble painfull to the ears and the mids got blurred.
If the 6/3 was a jumbo jet then the 6/4 with opamp LM4562MA and maplin power supply is the starship enterprise at warp 1. The great news is that the 6/4 still needs burning in so I am hoping it will improve even further. Maybe it will get to warp 3 after cap replacements in mod part 2 and a decent burn in period. It will never be at warp 6 but then the dacs' and cd players that can cost thousands of pounds to get you there. Was it worth the cost of 70 euros to upgrade- you bet your ass it was!!!! :lol:

[StanleyB]

That's a very good job that you have done. Well, that your engineer freind has done;).
The TC-7510 can be made to sound even better than it already does, and its low initial outlay should encourage a lot more people to start with a basic unit and then improve from there. You could buy a DAC kit that cost more, but would struggle to match the TC-7510 even in its basic form. Or you can get a cheap TC-7510 and spend a bit of time and less than £20 to get £5K CDP beating performance.

I am surprised you had to pay so much for the Maplin PSU. In any case there is a new one I have found. I just need to consult the seller about a bulk purchase.

[kalozois100]

That's a very good job that you have done. Well, that your engineer freind has done;).
The TC-7510 can be made to sound even better than it already does, and its low initial outlay should encourage a lot more people to start with a basic unit and then improve from there. You could buy a DAC kit that cost more, but would struggle to match the TC-7510 even in its basic form. Or you can get a cheap TC-7510 and spend a bit of time and less than £20 to get £5K CDP beating performance.

I am surprised you had to pay so much for the Maplin PSU. In any case there is a new one I have found. I just need to consult the seller about a bulk purchase.

Thanks.
Maplin uk would not post to Cyprus so got from local distributor. The price above includes postage from uk that the distributor charged me since he didn't have it in stock. Ah and the price is in euro so with exchange rate its not that far off uk price.

[NRG]

That's a great result, well done. With the caps in place I predict it will sound even better! ;)

I made another change last week, snowed in for the third time in a week I had time on my hands to finally implement a pulse transformer on the SPIDF output of my squeezebox:

http://i94.photobucket.com/albums/l82/_NRG_/other/Image1-1.jpg

Shameless borrowing of the idea! ;)

Before, the SB SPDIF output as seen on the 'scope was a bit of a mess, with the cct in place the much cleaner scope trace confirmed what my ears where telling me...wow!

I wish I had implemented this ages ago, the improvement is very dramatic, detail has improved again but even more so this time and I'm hearing things not heard before on many tracks...one MP3 download of a recent Eva Cassidy 'new material find' was surprising, previously I'd thought it was either a poor recording (its still not great TBH) or the effects of heavy MP3 compression but what I thought was low level background noise, similar to white noise was in fact audience chatter in the background.. I can now make out talking and laughter!

I think I've got as much as I need to out of the 7510 with MOD21 pt1 and 2 plus my PSU modifications so its time to start another project based on the TDA1541A to see how that compares.

[Covenant]

Very impressed with your improvement to the SB3. Is this too difficult for a novice to do? I have a linear supply and was pondering what upgrade I could do next.

[leo]

That's a great result, well done. With the caps in place I predict it will sound even better! ;)

I made another change last week, snowed in for the third time in a week I had time on my hands to finally implement a pulse transformer on the SPIDF output of my squeezebox:

http://i94.photobucket.com/albums/l82/_NRG_/other/Image1-1.jpg

Shameless borrowing of the idea! ;)

Before, the SB SPDIF output as seen on the 'scope was a bit of a mess, with the cct in place the much cleaner scope trace confirmed what my ears where telling me...wow!

I wish I had implemented this ages ago, the improvement is very dramatic, detail has improved again but even more so this time and I'm hearing things not heard before on many tracks...one MP3 download of a recent Eva Cassidy 'new material find' was surprising, previously I'd thought it was either a poor recording (its still not great TBH) or the effects of heavy MP3 compression but what I thought was low level background noise, similar to white noise was in fact audience chatter in the background.. I can now make out talking and laughter!

I think I've got as much as I need to out of the 7510 with MOD21 pt1 and 2 plus my PSU modifications so its time to start another project based on the TDA1541A to see how that compares.

That circuit looks familiar:eyebrows:

I'm actually surprised nobody has tried a 1:1 pulse transformer on one of the TC-7510 spdif inputs to allow for easy comparing;)

[kalozois100]

That's a very good job that you have done. Well, that your engineer freind has done;).
The TC-7510 can be made to sound even better than it already does, and its low initial outlay should encourage a lot more people to start with a basic unit and then improve from there. You could buy a DAC kit that cost more, but would struggle to match the TC-7510 even in its basic form. Or you can get a cheap TC-7510 and spend a bit of time and less than £20 to get £5K CDP beating performance.

I am surprised you had to pay so much for the Maplin PSU. In any case there is a new one I have found. I just need to consult the seller about a bulk purchase.

You got me thinking there stan. what further mods did you have in mind apart from mod 21 part1 and 2 for twenty pounds?:scratch:

[Stratmangler]

That's a great result, well done. With the caps in place I predict it will sound even better! ;)

I made another change last week, snowed in for the third time in a week I had time on my hands to finally implement a pulse transformer on the SPIDF output of my squeezebox:

http://i94.photobucket.com/albums/l82/_NRG_/other/Image1-1.jpg

Shameless borrowing of the idea! ;)

Before, the SB SPDIF output as seen on the 'scope was a bit of a mess, with the cct in place the much cleaner scope trace confirmed what my ears where telling me...wow!

I wish I had implemented this ages ago, the improvement is very dramatic, detail has improved again but even more so this time and I'm hearing things not heard before on many tracks...one MP3 download of a recent Eva Cassidy 'new material find' was surprising, previously I'd thought it was either a poor recording (its still not great TBH) or the effects of heavy MP3 compression but what I thought was low level background noise, similar to white noise was in fact audience chatter in the background.. I can now make out talking and laughter!

I think I've got as much as I need to out of the 7510 with MOD21 pt1 and 2 plus my PSU modifications so its time to start another project based on the TDA1541A to see how that compares.

I'm intrigued - any chance of some photos/parts used info ?

Chris:)

[leo]

I might be doing a Squeezebox Duet Receiver modding thread when I get chance, any mods for the SB3 etc could be added on there

The part above T1 should be a 1:1 pulse transformer, Newava do some decent ones which are not expensive , model S22083 is a good start

R2 is for loading the secondary of the transformer

U1 is the part of the S/PDIF buffer chip inside the SB3

C1 should be low inductive physically small as close to the transformer as you can get

Run 75R mini co-ax from the loaded secondary to a 75R BNC socket used for spdif out

[trailer]

If you're in Cyprus then it might be a bit difficult unless you have a Wolfson agent there.

Try googling Wolfson. There are a few distributors in the UK.

[NRG]

I might be doing a Squeezebox Duet Receiver modding thread when I get chance, any mods for the SB3 etc could be added on there

The part above T1 should be a 1:1 pulse transformer, Newava do some decent ones which are not expensive , model S22083 is a good start

R2 is for loading the secondary of the transformer

U1 is the part of the S/PDIF buffer chip inside the SB3

C1 should be low inductive physically small as close to the transformer as you can get

Run 75R mini co-ax from the loaded secondary to a 75R BNC socket used for spdif out

I ended up using this tx:

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1087809

and some RC55Y resistors, seems to work really well

Leo, what's needed on the DAC? another tx and what primary loading? or just an input blocking cap...?

--Neal

[leo]

I ended up using this tx:

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1087809

and some RC55Y resistors, seems to work really well

Leo, what's needed on the DAC? another tx and what primary loading? or just an input blocking cap...?

--Neal

Be less effective seeing as though you've now done it on the SB output although you can still try it on one of the dacs inputs too.

1:1 pulse transformer before one of the inverters inputs ( I presume it uses one before the CS8414) then loading resistor on transformers input http://www.diyaudio.com/forums/attachment.php?s=&postid=645151&stamp=1116466114

[ultraviolet]

This sounds an interesting mod. Currently using my v old pc with awe64 spdif to feed TC-7510 but could do with isolating DAC electrically from PC. Might add tx this weekend if I can get hold of one.

Also mulling over adding PIC to DAC to extract info from ICs like current sample rate n stuff to light some LEDs. Just for my peace of mind that windows isn't fiddling about with the sample rate - although I suspect the awe64 only supports 44.1 anyway.

[kalozois100]

Hi to all,
I have accidently ordered pk black gate capacitors from abroad in stead of the FK types for use in the mod 21 part one. I have since found out the pk types are tiny. unfortunately they have been dispatched. Will they fit in the pcb and if so will they be effective or should I place another order for the FK types that are considerably more expensive( PK types are 1 dollar each and the FK types are 5 dollars each)? . I hate it when I order the wrong parts - its like stepping in dog shit!!:lol:

[Jamal]

Hi everybody. My friend gave me a 7510 and it sat on a shelf for months. I finally brought it out to give it a try and found made very impressive improvements over the CS4398 in my Emu 1616m before break in. Better pacing and dynamics, "truer" tonality. Not that any of you here are suprised.

My question is:

Would it be easy to remove the digital filter? Yes I know they look crummy on the scope.

[leo]

My question is:

Would it be easy to remove the digital filter? Yes I know they look crummy on the scope.

No, not as far as I know anyway, the digital filter is built inside the chip so cannot be bypassed

[StanleyB]

Would it be easy to remove the digital filter? Yes I know they look crummy on the scope.
It is not connected, so why would you want to remove it?

STan

[ultraviolet]

I tried a pulse transformer on PC spdif output to DAC earlier and I have to report that in my system it seemed to make absolutely no difference to the sound, which was a shame. Transformer was free though so not lost anything I guess.

Just waiting for new op amp to arrive to try out on DAC output now. If that doesn't make any difference to the sound then I shall have to assume my ears are broken.

[ultraviolet]

Hi to all,
I have accidently ordered pk black gate capacitors from abroad in stead of the FK types for use in the mod 21 part one. I have since found out the pk types are tiny. unfortunately they have been dispatched. Will they fit in the pcb and if so will they be effective or should I place another order for the FK types that are considerably more expensive( PK types are 1 dollar each and the FK types are 5 dollars each)? . I hate it when I order the wrong parts - its like stepping in dog shit!!:lol:

If caps are correct value and voltage then just bend legs to fit PCB holes?

[kalozois100]

I tried a pulse transformer on PC spdif output to DAC earlier and I have to report that in my system it seemed to make absolutely no difference to the sound, which was a shame. Transformer was free though so not lost anything I guess.

Just waiting for new op amp to arrive to try out on DAC output now. .
I found replacing the JRC4558 with LM4562MA made a vast improvement to the sound. :)

[NRG]

I tried a pulse transformer on PC spdif output to DAC earlier and I have to report that in my system it seemed to make absolutely no difference to the sound, which was a shame. Transformer was free though so not lost anything I guess.

Just waiting for new op amp to arrive to try out on DAC output now. If that doesn't make any difference to the sound then I shall have to assume my ears are broken.

Sorry to hear that. Does the card have an output TX already? How did you implement the cct? Did you remove the existing o/p cct? What tx did you use, they can be quite specific?

[ultraviolet]

No output TX just a line driver (I forget which one) with an RC circuit on its output. I tried 2 transformers - one was custom made by one of the switch mode PSU engineers at work and the other was salvaged from an old network card. I just connected to TX to the output - but with no blocking cap on input or resistor on output. I could try cap on input - I presume it stops the core saturating if theres any DC present. I assume the resistor on the output is only doing anything if no cable is connected.

I deduce that either the output was fairly clean anyway or the 7510 is not particularly sensitive to the signal quality on the SPDIF input. I could dig 'scope out and have a look at the waveforms but I prefer to listen for improvements rather than try to measure them.

[StanleyB]

the 7510 is not particularly sensitive to the signal quality on the SPDIF input.
The re-clocking cct takes care of business over a wide bandwidth and phase error range.

Stan

[NRG]

...and yet I found a worthwhile improvement implementing the pulse tx cct on the o/p of the SB...

[StanleyB]

...and yet I found a worthwhile improvement implementing the pulse tx cct on the o/p of the SB...
Good for you:).

[NRG]

....and picking up on this I've now got two SPDIF outputs from my Squeezebox to the 7510 DAC allowing AB test between the output from the pulse cct above and from the output of the Tent Labs X03 board. The Tent labs output is poorer on the scope and in practice also sounds worse...splashy treble and worse separation and definition (in comparison), so I believe there is mileage to be gained with this cct.

[kalozois100]

Regarding the maplin power supply:
When i received the maplin power supply i connected it with 13.5volts setting to the tc-7510 and had listened since on that setting. a friend suggested i try it back on the 12volt setting and after having done so i found the sound to be much better. I don't think my speakers could take the massive bass that the 13.5volts setting seems to produce . Also mids and highs seemed alot more defined. I don't know why i have experienced this phenomenon when others have found the 13.5 v setting better. another variable may be due to the replacement opamp from the one fitted as standard in the tc-7510. Anyway what matters is the better audio i'm getting so a suggestion to others is to try both 12v and 13.5v and for them to see which best suits their set up.

[Covenant]

Stan has advised me that he will have an inexpensive linear supply available in March some time.

[trailer]

Well having settled down listening (very happily I must add) to the 7520 I had a thought "What should I do with the now unused 7510?"

After a bit of conversation with Stan and viewing posts on here I decided to get the op amp changed out along with the capacitors for some Black Gates. The DAC has been replaced with the recommended Wolfson one. Total cost for the parts about twenty quid.

It is due back to me at the end of the week. The only downside to this? I'm out of the country for a couple of weeks so I'm afraid that I won't be able to give it a listen till then :(

It will be really interesting to compare it to the 7520.

Next step? 7520 hot rodding?

[kalozois100]

After a bit of conversation with Stan and viewing posts on here I decided to get the op amp changed out along with the capacitors for some Black Gates. The DAC has been replaced with the recommended Wolfson one. Total cost for the parts about twenty quid.


how do you change the dac chip in the tc7510 for a wolfson one? and where can you get your hands on a wolfson chip??:scratch:

[leo]

http://uk.farnell.com/wolfson-microelectronics/wm8716seds/24bit-dac-192khz-stereo-8716/dp/1354193?_requestid=404139

Changing the dac should only be done if your very confident , it would be easy to screw the thing up.
Some mods are ok for beginners, this is NOT one of them IMHO

You'd be best off asking somebody which has tried this mod to see if it brings a worthwhile improvement

A search on google http://www.head-fi.org/forums/f7/what-inside-berefsord-tc-7510-mk6-3-dac-327325/#post4234581

[leo]

Mod21

47uf caps, plenty of choices

Standard cheap types

http://uk.farnell.com/panasonic/eca1hm470/capacitor-47uf-50v/dp/9693785

Cheapish Audiophile types

http://uk.farnell.com/panasonic/eca1ham470x/capacitor-47uf-50v/dp/8767408

Blackgate, various grades

http://www.hificollective.co.uk/components/black_gate_caps.html

Elna Cerafine and Silmics

http://www.hificollective.co.uk/components/elna_capacitors.html


Mod21 part2

Lm4562

http://uk.farnell.com/national-semiconductor/lm4562ma-nopb/opamp-audio-dual-hf-8-so/dp/1685365

Choices of 220pf filter

Polypropylene
http://uk.farnell.com/wima/fkp2-220pf-5-100v/capacitor-220pf-100v/dp/1005983

polystyrene
http://uk.farnell.com/lcr-components/fsc-160v-220pf-2-5/capacitor-220pf-160v/dp/9520031

Mica
http://uk.farnell.com/cornell-dubilier/cd15fd221fo3f/capacitor-220pf-500v/dp/1264884

[trailer]

http://uk.farnell.com/wolfson-microelectronics/wm8716seds/24bit-dac-192khz-stereo-8716/dp/1354193?_requestid=404139

Changing the dac should only be done if your very confident , it would be easy to screw the thing up.
Some mods are ok for beginners, this is NOT one of them IMHO

You'd be best off asking somebody which has tried this mod to see if it brings a worthwhile improvement


That's why I didn't chance it myself.

I'll post my findings as soon as I get the listening done.

[ultraviolet]

Mod21

47uf caps, plenty of choices


Blackgate, various grades

http://www.hificollective.co.uk/components/black_gate_caps.html



I can't find blackgate 47u anywhere, I suspect stocks have finally run out. Which would you rate as a second best? Cerafine or Silmic?


Also what do ppl think about a linear PSU like this one;

http://www.maplin.co.uk/Module.aspx?ModuleNo=231&doy=26m2&C=SO&U=strat15

[leo]

I can't find blackgate 47u anywhere, I suspect stocks have finally run out. Which would you rate as a second best? Cerafine or Silmic?




In all honesty mate I'm personally not a huge fan of BG caps be it N, NX, NX Hi-Q, FK etc, they all add a particular signature to the sound which to me sounds like heavy colouration .
This is not to have a pop at BG's, people love what they do and thats fine;) I have used BG's in some apps before though to add a bit of flavour if I feel its needed.

The Elna's are also similar regarding having a particular signature, especially the Silmics , the audiograde caps use different internal materials like hemp, graphite etc which affects the sound.

Anyway enough blabbering:lol: I wouldn't rate Silmic better than Cerafine or vice versa, they do sound different, Silmics tend to have a more smooth presentation, Cerafines a bit more forward

You could be boring and just buy general purpose electrolytics, sorry for the s**t reply, hopefully somebody else can say which they like better:eyebrows:

[leo]

Also what do ppl think about a linear PSU like this one;

http://www.maplin.co.uk/Module.aspx?ModuleNo=231&doy=26m2&C=SO&U=strat15


Never tried it personally but if the voltage out is suitable it should be pretty decent, certainly hefty and probably be much better than a SMPS.
Main thing with some transformer based linears which are cheap is that you can sometimes get ones which suffer from mechanical hum/buzzing

[ultraviolet]

Thats a good reply! I've done MOD21 including op-amp at no cost and I've got a free 7 Ah battery tomorrow from work if I remember to pick it up. I was wondering about actually spending some cash now on some caps but I might buy a CD instead now.

I'm a bit cheesed off with myself as I cleared out the garage a bit before Christmas and chucked out a CB power supply 'cos it was a bit tatty and the power transistor had blown. I need about 13.5 V to charge the battery.

[NRG]

These guys have a number of 47uF BG's listed:

http://www.partsconnexion.com/catalog/CapacitorsElectrolytic.html

[leo]

Thats a good reply! I've done MOD21 including op-amp at no cost and I've got a free 7 Ah battery tomorrow from work if I remember to pick it up. I was wondering about actually spending some cash now on some caps but I might buy a CD instead now.

I'm a bit cheesed off with myself as I cleared out the garage a bit before Christmas and chucked out a CB power supply 'cos it was a bit tatty and the power transistor had blown. I need about 13.5 V to charge the battery.

If you notice Stan seems to use general purpose caps for the mod21, how about trying a couple of cheapies and then you can try more exotic parts later for tuning to personal taste

I used something similar to this for charging a 12v 7aH Yuasa battery which is used in the cheapo diy Nosdac http://cgi.ebay.co.uk/500mA-charger-for-6V-12V-sealed-lead-acid-batteries_W0QQitemZ120350818302QQcmdZViewItemQQptZ UK_ConsumerElectronics_Batteries_SM?hash=item12035 0818302&_trksid=p3286.c0.m14&_trkparms=72%3A1683%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318

[leo]

These guys have a number of 47uF BG's listed:

http://www.partsconnexion.com/catalog/CapacitorsElectrolytic.html

Nice selection of stuff on there, lots of resistors to try in my Sabre too:doh:

[kalozois100]

i got back my tc-7510 yesterday from electrical engineer. it now has the mod21 part one and two and the caps from part one are all black gates PK series 47uf/16v ( bought from parts connexion in Canada which shipped and arrived very fast - they also have 20% off caps sale at the moment!). Also the opamp is now the LM4562. Also using maplin p/s on 12 volt setting. I have had the tc-7510 on for 24hrs with the cd player on repeat to help burn in the new parts. I am already very very happy with the improvement in sound although i read that black gates take hundreds of hours to break in. i found the sound to be alot more detailed and there is alot more warmth that i have only experienced with vinyl until now. And very, very smooth audio for hours of listening without the fatigue factor. i'm sure the sound will get even better as it did with the cheap caps that were used in the mod 21 part one before, but boy its already good enough . I would say to all owners of the tc-7510 mark 6/3 not to leave it at that and find someone to do the modifications because the benefits are tremendous for the relative low cost of the mods.
The Beresford dac really is amazing value for money IMHO. I'm not sure how it compares to the tc-7520 but this tc-7510 with mod 21, part 1 & 2 is more than enough for me. :eyebrows:

[trailer]

The Beresford dac really is amazing value for money IMHO. I'm not sure how it compares to the tc-7520 but this tc-7510 with mod 21, part 1 & 2 is more than enough for me. :eyebrows:

If I had a pound for every time I've heard that about hi-fi ................

[James G]

That sounds great and it's where I want to be one day. I'm torn between getting the Silmic II's and the Black Gates though. I might have to try both.


Does anyone know of some type of adapter that you can solder on once and then just snap in different op amps so you can roll them like tubes solderless? Sorry, but I'm not sure what something like that would be called.

[Stratmangler]

The connector you refer to is called a DIL socket.

I've been scouring the web to see if it is possible to get surface mount sockets on a one or two off basis, otherwise you're looking at bending the legs on the ones normally available.

Chris:)

[NRG]

You can get these DIP to SOIC etc converters:

http://cgi.ebay.co.uk/Surface-Mount-Converter-SOIC-8-SMT-SMD-to-DIL-8-adapter_W0QQitemZ360122272673QQcmdZViewItemQQptZUK _BOI_Electrical_Components_Supplies_ET?hash=item36 0122272673&_trksid=p3286.c0.m14&_trkparms=72%3A1683%7C66%3A2%7C65%3A12%7C39%3A2%7C 240%3A1318

but the 7510 is surface mount so going to DIP is not easy...also I'm finding more and more the DIP version of many opamps are not available in the UK...

[leo]

You could solder a DIP socket to this DIP to SOIC socket http://cimarrontechnology.com/dip8toso8adapterpn031101b.aspx

Anywhere local that sells the above, wouldn't minda couple myself

[kalozois100]

If I had a pound for every time I've heard that about hi-fi ................

thats okay where do you want me to send my pound to get the ball rolling:lol:

[StanleyB]

Try this:
http://cgi.ebay.co.uk/5PK-SO8-DIP-SMT-SMD-DIP-ADAPTER-BASIC-STAMP-PIC-ATMEL_W0QQitemZ150302520884QQcmdZViewItemQQptZBI_E lectronic_Components?hash=item150302520884

[trailer]

thats okay where do you want me to send my pound to get the ball rolling:lol:

I was meaning the "more than enough for me" comment. I give you 2 weeks and you'll be looking to change/mod again.

I can give you my Paypal account details if you want..........:ner:

[kalozois100]

I give you 2 weeks and you'll be looking to change/mod again.


"" And ye shall know others as ye knoweth thy self " :ner:

[trailer]

Guilty as charged millord.

[kalozois100]

Guilty as charged millord.

We are all guilty of the same passion m8! but just for the moment to be content with the sound we hear is a very precious moment because as you say we all know it comes full circle , we go cold turkey and seek the next audio " fix " to further quality in sound......its in our nature...... and why we are on forums so we are not alone with this phenomenon. Anyway Its how I see it :)

[freddiecas]

as well as Mod 21 part 1 and 2, I swapped the 2200uF main smoothing caps for 4700uF 16V which just fit under the hood. (I use the Maplin 5A supply). Can't say I could hear much of a difference just from that swap, but the op-amp swap etc is REALLY worthwhile.

I shall remove the ceramic 0.1uFs across EC8 and 9 and replace with polyester or polypropelene too I think.

If I could only get the volume knob off ! I would beef up the smoothing on the front board and replace those mylars and see what could be done to the headphone amp.

[trailer]

I've just got round to listening to the 7510 with the BG/LM4562/Wolfson mods.

A quick question before I post on the sound (as I haven't had much of a chance to give it a proper listen yet). There seems to be a lot more hiss at highish volumes. The fixed output is quite high and I am having to use the variable output to get rid of this.

I suspect that this is something to do with the new DAC chip? Suggestions would be appreciated!

If Kalazois100 is interested I have a spare Wolfson DAC chip which I will happily post to you gratis if you want it?

[StanleyB]

There seems to be a lot more hiss at highish volumes. The fixed output is quite high and I am having to use the variable output to get rid of this.
I suspect that this is something to do with the new DAC chip?
The WM8716 has no analogue filter built in like the PCM1716E has, and the TC-7510 does not make use of the digital filter. So your output from the WM8716 relies solely on the partially filtered O/P around the opamp.

[trailer]

The WM8716 has no analogue filter built in like the PCM1716E has, and the TC-7510 does not make use of the digital filter. So your output from the WM8716 relies solely on the partially filtered O/P around the opamp.

Thanks Stan,

You know what the next question is going to be..............

[kalozois100]

I've just got round to listening to the 7510 with the BG/LM4562/Wolfson mods.

A quick question before I post on the sound (as I haven't had much of a chance to give it a proper listen yet). There seems to be a lot more hiss at highish volumes. The fixed output is quite high and I am having to use the variable output to get rid of this.

I suspect that this is something to do with the new DAC chip? Suggestions would be appreciated!

If Kalazois100 is interested I have a spare Wolfson DAC chip which I will happily post to you gratis if you want it?

Many thanks for the offer for the wolfson chip but i am very happy with the sound from the TC-7510. I do not intend to modify it any more.The combination of new opamp with black gate caps has pushed the dac into a league i could not have afforded with a cd player.it is now time to for me to get back to listening to music after all the mods. Perhaps someone else can benefit from your spare wolfson chip? (p.s. look out for the new thread i am about to open)

[trailer]

I've had a chance to listen to the modded 7510 today for a decent listen. It is very very good. With regard to the filtering on the Wolfson chip if anyone has any suggestions on how this can be done then I would be grateful of the input.

[leo]

Have you looked at the datasheets for the wm8716 evaluation boards? there should be some details in there to give you an idea

[StanleyB]

I remember they suggested a MFB or Sallen Key filter output.

[leo]

These diyers with your dac wanting to mod should be experimenting and evaluating rather than cheat and just ask for the answers:lolsign:

[StanleyB]

These diyers with your dac wanting to mod should be experimenting and evaluating rather than cheat and just ask for the answers:lolsign:
:scratch:. You got a point.

[trailer]

I was just trying to get the "best sound per pound" out of the DAC and put the foot out into the water.

I admit I'm not the best electronics engineer. Far from it in fact.

If it wasn't for this forum I wouldn't have considered going ahead with the mods in the first place. I have gone ahead with them at some considerable expense relative to the initial cost of the 7510 and was asking for some further advice.

I'm most certainly not looking for a free ride.

[StanleyB]

We're just pulling your G-string:ner:.

[leo]

Of course:eyebrows:

Anyway, ignore me, I've not had a fag for two weeks and feeling a bit peevish:lol:

[trailer]

I can't ignore you both. How do you think I'm going to get any decent advice otherwise? :youtheman:

[Ali Tait]

Stick with it Leo,it's worth it in the end! 6 months fag free and counting for me.. Best of luck mate.

[leo]

I can't ignore you both. How do you think I'm going to get any decent advice otherwise? :youtheman:

I don't like advising things I've not tried myself first, especially things which may require some tweaking to get best results

Did you try mailing the guy on that other site who tried the WM8716? http://www.head-fi.org/forums/f7/what-inside-berefsord-tc-7510-mk6-3-dac-327325/#post4234581 I don't even have a TC7510 so can't try anything out, maybe he altered the filter to be suitable too

BTW, try and ignore the bitching etc on that site

[leo]

Stick with it Leo,it's worth it in the end! 6 months fag free and counting for me.. Best of luck mate.

Thanks for the support Ali, its much appreciated;)
I'm just hoping the craving finally wears off:steam:
Anyway congrats to you too!

[leo]

I don't like advising things I've not tried myself first, especially things which may require some tweaking to get best results

Did you try mailing the guy on that other site who tried the WM8716? http://www.head-fi.org/forums/f7/what-inside-berefsord-tc-7510-mk6-3-dac-327325/#post4234581 I don't even have a TC7510 so can't try anything out, maybe he altered the filter to be suitable too

BTW, try and ignore the bitching etc on that site

Bugger, just noticed the guy has been banned from that site so that links not much use, sorry:(

[Ali Tait]

Thanks Leo :) The craving will go,give it time.Be strong!

[trailer]

Bugger, just noticed the guy has been banned from that site so that links not much use, sorry:(

No problem Leo, thanks anyway.

[leo]

No problem Leo, thanks anyway.


Thing I'd do is run leads from the dac chips output and build a circuit on vero board using through hole parts which allows for easier tuning rather than fudge about with the onboard standard SMD circuit

[fault151]

Hi guys,i modded my dac today to have an LM4562 op amp and i also replaced the c5+c6 caps on the dac with some 220pF WIMA caps. Based on Stans recommendations,this should make an improvement to the sound. I already added the mod 21. Heres a few pics of my mod, was fiddly.

Has anyone else done it too? I swear i end up having to turn up my amps louder to drive my headphones. Anyone else found that?


http://img14.imageshack.us/img14/3543/dac3.jpg (http://img14.imageshack.us/my.php?image=dac3.jpg)

http://img528.imageshack.us/img528/5650/dac5.jpg (http://img528.imageshack.us/my.php?image=dac5.jpg)

[StanleyB]

Try 10K for R18 and R19, instead of the 8.2K.

[fault151]

Try 10K for R18 and R19, instead of the 8.2K.

Cheers, ill just have to use standard resistors soldered to the top. Will that be ok?

[leo]

Don't forget to give it chance to run in, new parts can make the sound seem a bit closed in when their fresh normally opening up after things have settled down.

Give it a few days see how it goes;)

[James G]

Ok, here's my crazy hodgepodge of a mod. I'm still experimenting with parts but thought I would post some photos before I totally ruin it. :( I have no knowledge about electronics (as some of you already know) and have just been leeching ideas from the other forum members.

The parts I got were pretty cheap. Actually most of the money I spent was on tools I needed to complete the job. But I love having tools, so this was money well spent. Probably the best thing I got was a large magnifying glass on an adjustable arm. Apart from magnifying, it really focuses the light onto the work area!

I'll start with the most obvious ones from the photos.


EC15-1 & -2: 4700uF/25v Nichicon Muse FW
Ok, extreme overkill right? The kid in me took over when I saw these big gold caps and I bought them without even thinking about whether they'd fit in the case or not. 　They are just being supported in air by the stiffness in the wire.

IC1: For the moment - AD8066
I fitted a DIP socket here so I can roll opamps without too much hassel. I know, I know, there's a SOIC-8 in there right now, but I didn't want to solder it in because there is a LME49720, OPA2134, and LT1364 waiting for their chance to shine (after I give the new parts a good run in).

Ribbon Cable: Solid core tinned copper
I broke the ribbon cable twice taking it apart too much and got frustrated and one night just replaced it all.

EC3, 4, 8 & 9: 47uF/16v Nichicon Muse Fine Gold
Not too expensive and good reputation.

EC1: 1000uF/16v Nichicon Muse FW
They are cheap.

C5 & 6: 120pF/50v Polypropylene Panasonic ECG
Jury's still out on this one. I had a WIMA 220 pF/100v here but the treble seemed a bit zingy, so I'm trying other things. YMMV.

CC1 & 2: 220pF/50v Polypropylene (forgot the maker, anybody know from the pics?)
I don't know what these do, I tried it for a while with CC1 & 2 removed, but the sound seemed too upfront, like the trumpet was blasting right in my face. I put these in and it seemed to move it back a bit. I have a small room and my speakers are near, so YMMV.

EC20 & 21: 10uF/50v Nichicon Muse FW

Power Supply: 12v/5a/60w power brick from an old laptop


So after I get everything settled in I'm going to start rolling opamps to see which one has the best synergy with my kit. Maybe after I get my mind set I'll set the opamp properly on the surface and drill small through holes for the other caps.

Any suggestions are most welcome.

But for now, I'm going to enjoy the music! :gig:

[fault151]

I have the Nichion golds and Panasonic FM's. Both worked pretty well for me.

Are modding the caps in positions c5 + c6 at all? Edit; sorry i couldnt see the mpics before. I see you have changed them. Looks pretty neat! I know how fiddly it is!

[fault151]

jgarner71 = by any chance are you finding you need to drive your amps a bit harder to get the dac to sound right with these mods?

[James G]

jgarner71 = by any chance are you finding you need to drive your amps a bit harder to get the dac to sound right with these mods?

Hey, you can call me James. It's hard to say really. I can barely turn the dial on my amp as it is. I was using the WIMA's before and though it seemed louder (more forward) then.

I'm actually trying to go for a slightly relaxed, but fast and detailed sound, if that makes any sense. I don't want the musicians to sound like they are in my living room, but on a virtual stage behind the wall. But no DSP junk. I thought Stanley's DAC did this very well right out of the box.

I've been running it in for about 24hrs in it's current config now and I'm not frowning to say the least! :)

:band:

[fault151]

Hey, mine ssems to sound detailed, but i swear i can hear distorion and noise. Stan seems to think it may settle down over time. Or it could be that it's picking up lot's of detail. I'll shall see.

I haven't modified the two caps next to c5 + c6 like you have. But in might.

Are you doing anything else to it?

[leo]

Looking good chaps

Be careful with AD8066's, these can oscillate in some circuits, a tell tale sign is they go hot to the touch

Wima's, hmmm well I never got on with the FKP or FKP2 Wima's, I once tried them in the filter for my Sabre dac, highs had a sort of spitty quality which never went away so I changed them to some Evox low inductance, the spit was gone:)

I've noticed a few use Nichicon FG, these are reported to take quite a lot of burning in, frequencies may seem to be all over the place before they have had chance to form.

Audiograde parts are a real pain:doh:

[fault151]

I hope that is what is wrong with mine.

leo when you say the sabre, do you mean the buffalo sabre dac? From twisted pear audio?

[leo]

I hope that is what is wrong with mine.

leo when you say the sabre, do you mean the buffalo sabre dac? From twisted pear audio?


It could be the problem, don't suppose you have a scope?

Yes, my Sabre was the Buffalo from TP, its had a lot of modifications done to it though and doesn't sound like the stock unit

[fault151]

Cool, id love to see some pics! i too have the buffalo +the opus with metranome. What do you think of the sabre as a stock unit? What have you actually done to yours?

I haven't got a scope, i'm going to have serious check and see if i can spot anything. I'm tempted to send it to one of you guys for a second opinion on the sound.

[leo]

If you had a scope you could check the chip for any instability problems, oscillation can be clearly seen on a scope

Does the chip feel physically hot to the touch? obviously be very careful if trying that, if your not comfortable don't do it:)

I started a thread here for the Buffalo http://theartofsound.net/forum/showthread.php?t=1152&page=4 ,
I'm currently playing about with an output stage.
This dac is now my main reference which others are judged against

I've only heard the 7510 Mk6/4 with Mod21, I may pick one up if I see any going dirt cheap, mainly just to mod etc and start a new thread in the diy section , the Buffalo is keeping me busy at the moment

[trailer]

Leo,

I'll send you my modded 7510 down for further analysis if you like. Costs covered of course.

[fault151]

If you had a scope you could check the chip for any instability problems, oscillation can be clearly seen on a scope

Does the chip feel physically hot to the touch? obviously be very careful if trying that, if your not comfortable don't do it:)

I started a thread here for the Buffalo http://theartofsound.net/forum/showthread.php?t=1152&page=4 ,
I'm currently playing about with an output stage.
This dac is now my main reference which others are judged against

I've only heard the 7510 Mk6/4 with Mod21, I may pick one up if I see any going dirt cheap, mainly just to mod etc and start a new thread in the diy section , the Buffalo is keeping me busy at the moment

Wow, just looked at your pics, you have been busy! Id love to hear it compared to mine as a stock unit. I see you also have a slee solo. I seem to remember chatting to you a while back on rock grotto forum.

What is your main amp you run this with?

If the scope isn't expensive, i'll get one and give it a try. I'll test the heat coming form the op amp tomorrow and let you know. I'm pretty keen to get it sorted.:)

[freddiecas]

Hi, how did you get to the bottom of the headphone pcb to change the ribbons? My volume knob is on so tight I am afraid of levering it off in case I break the pot? I wanted to change the electrolytics and those mylars on that pcb too :)
regards,
Fred

[James G]

Be careful with AD8066's, these can oscillate in some circuits, a tell tale sign is they go hot to the touch

Thanks Leo. After my last experience that's the first thing I did after powering it up. :)

Maybe I'll try some of those Evox in the future. Your right about the parts. It sounds different than yesterday. I promised myself I'd give it 2 weeks before passing judgement though.

Edit: On second thought I was able to get a sensitive part or my hand on the AD8066 and noticed it's ever so slightly warm. I couldn't feel it with my finger tip. It doesn't sound bad but maybe I'm not getting the best performance. Any thoughts?

[James G]

Hi, how did you get to the bottom of the headphone pcb to change the ribbons? My volume knob is on so tight I am afraid of levering it off in case I break the pot? I wanted to change the electrolytics and those mylars on that pcb too :)
regards,
Fred

What I did was get some needle nosed pliers behind the base of the knob from the inside. Then applied firm pressure and turn the knob a little each time. Eventually the glue will give way. Unless they used super glue on yours. :)

[snowflake]

Hi,

I have somewhat succeeded with MOD 21 part one. (Inadvertently burnt off some copper tracks along the way too!) and I'm moving onto part 2

my LM4562MA is already on it's way and I basically have 3 questions.

1. I have these caps. I believe they are 220pF. But I have no idea what make or how suited they are for audio. bought it off a local electronics shop. Do I have to get the WIMA ones that Stan specifies?

2. When soldering in the caps (the rectangular ones), is there polarity to observe?

3. Can i just swap out the opamp and replace it with the LM4562MA without adding the capacitors?

I think i'm somewhat handy with the soldering iron, but i have zero electronics knowledge. Any help or advice is greatly appreciated!

My unknown caps
http://i39.tinypic.com/feo0np.jpg

[fault151]

Hi you dont need to use wimas, they are just renound as being good quality, but some poeple don't like them. Its just a preference.

The wimas don't have a polarity. So can go eitther way.

As far as i am aware i thin the caps are meant to be installed with the op amp as this is part of the sound. Soi think it's a yes, they do need installing at the same time. Im sure Stan will correct me if i am wrong.

I would do the op amp forts beofee the caps if i were you. Its easier as the space is tight. Alos use a sharp knife to chop the legs of your old op amp, remove its body and then unsolder the remaining legs. Thats the wy i did it.

[trailer]

I can't get the Wolfson to stop being noisy. Sodding thing.

I guess its time to go back to the standard chip. I guess no one has experienced the noise between songs just doing the Op Amp / cap change out?

[kalozois100]

I can't get the Wolfson to stop being noisy. Sodding thing.

I guess its time to go back to the standard chip. I guess no one has experienced the noise between songs just doing the Op Amp / cap change out?

Go back to burr Brown M8 - it sounds really good with the LM4562MA opamp. :)

[trailer]

Looks like that's the plan. Like I said, I've got a spare Wolfson here if anyone wants to have a shot with it.

[leo]

Hi,

I have somewhat succeeded with MOD 21 part one. (Inadvertently burnt off some copper tracks along the way too!) and I'm moving onto part 2

my LM4562MA is already on it's way and I basically have 3 questions.

1. I have these caps. I believe they are 220pF. But I have no idea what make or how suited they are for audio. bought it off a local electronics shop. Do I have to get the WIMA ones that Stan specifies?

2. When soldering in the caps (the rectangular ones), is there polarity to observe?

3. Can i just swap out the opamp and replace it with the LM4562MA without adding the capacitors?

I think i'm somewhat handy with the soldering iron, but i have zero electronics knowledge. Any help or advice is greatly appreciated!

My unknown caps
http://i39.tinypic.com/feo0np.jpg

Those are ERO MKP1830, they are far superior than the Wima's! low inductance

Only fit them if you know the value though, is there any numbering on top of the cap?

[leo]

I can't get the Wolfson to stop being noisy. Sodding thing.

I guess its time to go back to the standard chip. I guess no one has experienced the noise between songs just doing the Op Amp / cap change out?

Hmm, so does the chip mute when no music is playing? without knowing the original 7510 output circuit I can't advise what to swap to what, it needs scoping mate.
Your going to need Stan on this, ideally it wants tweaking

Have you scanned all evaluation board schematics for the Wofson chip? it needs comparing against the TC-7510 circuit and then working out what needs to be added or changed

[trailer]

Hmm, so does the chip mute when no music is playing? without knowing the original 7510 output circuit I can't advise what to swap to what, it needs scoping mate.
Your going to need Stan on this, ideally it wants tweaking

Have you scanned all evaluation board schematics for the Wofson chip? it needs comparing against the TC-7510 circuit and then working out what needs to be added or changed

Leo,

Thanks again for your reply, always appreciated. Like I've said I'm no great shake on the DIY front, so the idea of scoping the output to see what's going on would be OK, but after that I would have no idea of the way forward!

I've pursued a couple of paths since, including Stan and getting in contact with the link you posted on the Head-Fi forum, and it doesn't seem like a quick fix!

It might be an easier option just to go back to the original chip. :scratch:

[snowflake]

Thanks for the quick replies! It is much appreciated.

I can't wait for the LM4562MA to arrive on Tuesday!


Those are ERO MKP1830, they are far superior than the Wima's! low inductance

Only fit them if you know the value though, is there any numbering on top of the cap?

You can recognize caps just by looking at them? Wow.

Better than WIMA's? Woo Hoo! The numbers at the top say n22 J 100

[leo]

Leo,

Thanks again for your reply, always appreciated. Like I've said I'm no great shake on the DIY front, so the idea of scoping the output to see what's going on would be OK, but after that I would have no idea of the way forward!

I've pursued a couple of paths since, including Stan and getting in contact with the link you posted on the Head-Fi forum, and it doesn't seem like a quick fix!

It might be an easier option just to go back to the original chip. :scratch:

Yes, may be right regarding easier to stick another PCM1716 back in

I promise once I get around to getting one of these 7510 dacs I'll try as many mods as possible and start a new thread in the diy section, probably do a sticky or something seeing as though theres a bit of interest for tweaking these things

[leo]

Thanks for the quick replies! It is much appreciated.

I can't wait for the LM4562MA to arrive on Tuesday!



You can recognize caps just by looking at them? Wow.

Better than WIMA's? Woo Hoo! The numbers at the top say n22 J 100


Sad isn't it:lolsign: I normally know the brands of electrolytics by looking at the vent markings on the top of the cap too:o

N22 usually is 220pf J is 5% for the tolerence and 100 is 100v so they should be right ones to try

[fault151]

Problems with gain and sound that I reported earlier in this thread have now been solved! I will post an entry on my blog very soon (as soon as I have some decent pics) to show you guys and help out anyone who may be having the same problems.

Heres a link to my blog in advance. (http://www.fault151.blogspot.com)

[PJPro]

I'm just about to perform Mod21 and Mod21pt2. Clearly, the mods are to the output stage. So, will the upgrade effect the variable output only or will the fixed output be similarly upgunned? How about the headphone amp? I'm assuming the headphone amp is located adjacent to the volume pot so the performance through headphones will not change.

Thanks for clarifyng this for me.

[PJPro]

Just seen this quote from Stanley.

"However, a regulated linear power supply of at least 300mA and not more than 15V off load gives better bass handling ability and a fuller sound."

Anyone know what the ideal current is?

[PJPro]

I'm just about to perform Mod21 and Mod21pt2. Clearly, the mods are to the output stage. So, will the upgrade effect the variable output only or will the fixed output be similarly upgunned? How about the headphone amp? I'm assuming the headphone amp is located adjacent to the volume pot so the performance through headphones will not change.

Thanks for clarifyng this for me.
Is this a stupid question or is the answer not known?

[James G]

Is this a stupid question or is the answer not known?

Hi PJ. Those mods will affect all output for the 7510. Fixed, variable, and phones.

[PJPro]

Hi PJ. Those mods will affect all output for the 7510. Fixed, variable, and phones.
Thanks jgarner71.

I am performing Mod 21 parts 1 and 2 and documenting the build here (http://community.whathifi.com/forums/t/241888.aspx).

[leo]

Be careful with Rubycon ZA's, their good for digital supply decoupling but used in the signal for blocking DC may be a bit bright and sharp tbh

[PJPro]

Thanks for the advice Leo. I should have asked before I bought them. I picked up the spec from this forum and simply searched for some that met that spec eg 16V 47uF.

Anyways, the overall result sounds pretty good.....

[PJPro]

Leo, would you care to recommend an alternative cap?

Grateful for the benefit of your experience.

[leo]

Ones to usually avoid for blocking DC is very low esr types and things like polymer as these can be electrically leaky and also tend to sound sharp (fine if thats what you want)

I don't have one of these dacs so never had chance to compare but the ones that are usually favoured by the diyer are

Silmic (have a smooth character, slightly warm , some say mellow) usually found on ebay, digikey and some of the online places offering upgrade parts

Panasonic ECA audiograde, the ones in a metalic blue sleeve (similar sounding to above, pretty safe sounding in the extremes ) can be had from Farnell

Blackgate , these are getting scarce now , quite expensive, places like Hificollective, Audiocom etc may still have some
They take an age to burn in (go through the forming process)

Nichicon FG or KZ, well priced but not easy to buy over here, sometimes seen on ebay etc, possibly digikey, not a bad cap for the money

You can also try general purpose available from Maplin etc, considered shite by the hard core diyer, some will say you can't hear a difference
Technically these will be the worse, poor HF etc
If you can't hear any difference between these and the audio classed ones I wouldn't worry about it

Because these caps have bias voltage on them most should be fine, I'd still avoid very low esr types though with the small exception of Panny FC

[PJPro]

Yeah, someone over on the WHFSV site recommended Silmic too. Thanks for your advise.

[waltwhy]

I attempted the mod21 pt2 on a 7510 mk6/4. I used the LM4562MA opamp with CORNELL DUBILIER 220PF, 500V Caps. The sound is good and at first listen I was pleased with the results. As the DAC played I began to hear noise in the left channel. After stopping the source signal the noise continues in the left channel. The sound is like a muted popping. It is not a hum or the sharp static associated with loose connection. Any advice on how to start the trouble shooting process? I am a newbie and won't be insulted by people pointing out the obvious.

[StanleyB]

My 1st guess would be to suspect the LM4562 of having suffered a breakdown due to anti static handling issues. Also check for any signs of solder flux between the pins. Changing surface mount chips is a terrifying job.

Stan

[waltwhy]

My 1st guess would be to suspect the LM4562 of having suffered a breakdown due to anti static handling issues. Also check for any signs of solder flux between the pins. Changing surface mount chips is a terrifying job.

Stan

It might be the flux. What should I use to clean it, alcohol and swab? I also have a 4032 coming. If I swap out the 4562 with it, are there any further considerations?

[StanleyB]

You'll need a 100nF ceramic cap between pin 4 and 8 of the IC. I use alcohol.

[waltwhy]

I cleaned the flux with alcohol and resolder one of the cap pins. Still had noise when I reconnected that continued when unit was turned off. The noise finally stopped when I disconnected the power. Surprisingly the noise stopped seconds after bein reconnected and has not returned. Everything sounds great. Must be a ghost in the machine.:scratch:

[Phileas]

Starting with the simple upgrades that do not require opening the DAC:


question I get asked is about USB. Again, Maplin does a unit that fits between a USB port and the TOSLINK input of the TC-7510. USB ADAPTER (http://www.maplin.co.uk/Module.aspx?ModuleNo=34128).

Apparently, this adaptor resamples to 48kHz. I'm guessing this is not a good thing?

[waltwhy]

I should have left well enough alone. I modded my 7510 mk6/4 with a LM4562 opamp and it sounded great. But I read about several peoples' preference for the 4032 and that prompted me to remove the LM4562 and install a dip adaptor from Browndog. Instead of cutting the legs off of the LM4562 I tried to tease it off so I could remount it to use it with the Browndog. Although this attempt partially damaged the contacts on the CB, I was able to get an OPA2132 dip chip to work with some noise. I then mounted a THS4032ID with a 100nf cap over pins 4 and 8 onto the Browndog and smoked the chip. :smoking:

At this point I just wanted to get back to where I started from but removing the adapter and remounting the LM4562 was more than the board could be expected to take and now I have a dead DAC. It is the second 7510 that I have butchered in 6 months! I am not looking for sympathy and must admit that it felt pretty good when I got the first LM4562 installation right. I guess what I have learned is, if I plan to try to various opamps on the 7510 I should install the adapter first to avoid repeated stress on the circuit board. :doh: I hope that this tale can help someone else to avoid a similar fate.

DACless in Stamford

[leo]

Why not just build a new output stage on vero and wire it in;)

[waltwhy]

Why not just build a new output stage on vero and wire it in;)

Would love to try it but I would need a very patient coach.

[chrism]

Anyone had a go at swapping CC1 and CC2 caps and if so any beneficial changes to the sound? Would something like a Wima 220pf be worth a go (I have a couple spare).

I am looking to improve the transparancy of the 7510 via the variable outputs a tad.

Regards

[StanleyB]

What I have tried is to replace the opamp to a LM4562 and to replace the resistors around the opamp for high precision metal film 1/8 Watts types. I also replaced the four surface mount caps for a couple of WIMA types I got from Maplin. But the job is a bit tricky. First the PCB needs to be removed from the case and some of the electrolytic caps need removing so that you can get to soldering the new resistors and caps. Not something for the faint of heart.

Stan

[chrism]

Hi Stan,

I have already done the 4032 opamp swap and Mod21 part 2 (I have the Wima's in C5 and C6). Could you let me know the ref codes for the others worth trying.

Regards

[chrism]

Does anyone know the optimum solid core wire size to replace the ribbon wire on the 7510 as jgarner71 has done on page 19 - reply 189 (amp and diameter)?

The ribbon cable on my 7510 is looking a bit worn/breaking and I would like to replace it with similar stuff.

Regards

Chris

[freddiecas]

my ribbon cables also broke after taking the boards out of the case several times for modding. My symptoms were the input switches not responding and the leds not lighting up if the end wires broke. I replaced both ribbons with 0.6mm dia solid core wire which fitted the pcb holes fine and was easy to cut and trim to identical lengths for a neat looking job. However solid core might not the best choice if continuing to flex the boards about but since I don't need to take the boards out again it's ok. The hardest part is desoldering the ribbon without lifting any pads or tracks on either side of the board so a good spring loaded desoldering "sucker" is worthwhile.

0.6mm dia solid core = 0.28 mm2 tinned copper with 0.3mm pvc insulation, 1mm overall dia, 70 deg C rating 1.8A, 0.064 ohm/metre

[chrism]

Thanks Freddiecas.

[PaulJ]

I did some additional modifications after the mod21 modification. I am not sure if it is posted already. I am very enthusiastic about the improvement. I have done some reverse engineering and draw the schematic around the opamp. In my opinion a few components are not necessary any more. I removed MC2 and of course the one in the other channel. Because R11 was replaced by a solder bridge this capacitor lose its function and becomes even dangerous. It is now placed directly at the inverting terminal of the opamp and can cause ringing or overshoot. I also removed R16 and the one in the other channel because this resistor only forms a DC load of the opamp.
http://imagemoo.com/images/attachmentjpegwytt_thumb.jpeg (http://imagemoo.com/viewer.php?file=attachmentjpegwytt.jpeg)

[PaulJ]

My list of modifications at the TC-7510:
EC8/EC9/EC?/EC? electrolytic capacitors were replaced by four 180uF capacitors. This was part of “Mod21”.
R13/14 resistors replaced by a solder bridge. Was also part of “Mod21”.
Opamp replace by a low distortion type. I have used AD8028 and ADA4841-2. Last one I blew up during measurement but it worked fine.
MC1/MC2 removed because of “Mod21” it could not work as filter anymore so you better can remove this ceramic capacitor from the signal path.
R12/R16 removed because it was a load for the opamp and has no function regarding signal quality.
C6/C7 Removed. First I replaced these ceramic capacitors with a 220pF film type (styroflex) capacitor. Because of the new wideband opamp you have to be sure that the circuit is stable also with the amplifier connected. I did some measurements with an oscilloscope and indeed there where high frequency oscillations, not sure but you have to think about 10MHz or so. You have to modify the characteristics of the opamp circuit to stop the oscillation. My first and easiest attempt was to remove the feedback capacitor C6/C7 and luckily it worked. Additionally, if you can remove a capacitor from the signal path it is always better then the best capacitor.
Extra capacitors placed in the analog power supply of the PCM1716 DAC and connected it to pin 15. This is inspired by the “wire mod” mend for the Wolfson DAC. The purpose of the original “wire mod” was to connect the +5V power supply to pin 15 of the DAC. I picked the local +5V and made it clean with a 180uF + 100nF ceramic.
http://imagemoo.com/images/mod3cjpgepam_thumb.jpg (http://imagemoo.com/viewer.php?file=mod3cjpgepam.jpg)

I have never done measurements at a DAC before. I am not sure if it is normal but you can measure a high frequency (quantization) noise level of about 100mV peak peak! Because C6/C7 is removed this high frequency goes to the amplifier. It went also strait through the amplifier to the loud speakers.

Noise at output DAC:
http://imagemoo.com/images/noise1jpgpbol_thumb.jpg (http://imagemoo.com/viewer.php?file=noise1jpgpbol.jpg)

Noise + music:
http://imagemoo.com/images/noise2jpgus6r_thumb.jpg (http://imagemoo.com/viewer.php?file=noise2jpgus6r.jpg)

[PaulJ]

I tried to figure out what settings are selected for the PCM1716 DAC chip. I am confused about the DE-EMPHASIS setting, pin 26 and 27. It was clear that pin 26 is connected to 0V, but pin 27 had at least no connection to 0V or +5V. A possibility is that this pin is controlled by the crystal interface chip (CS8414, I think). That should be the correct way. The problem is that I have tried to measure a connection but I could not find one. Maybe the connection is blew away during my experiments. If this pin (pin 27) is left floating then a pull up in the PCM1716 pulls to the +5V and that means that DE-EMPHASIS is selected!

[StanleyB]

The problem is that I have tried to measure a connection but I could not find one. :eyebrows:

[PaulJ]

DE-EMPHASIS problem solved! The output of the CS8414 is connected via a transistor to pin 27 of the DAC. The transistor is necessary because the control signal needs to be inverted!

[steve dixon]

Next question I get asked is about USB. Again, Maplin does a unit that fits between a USB port and the TOSLINK input of the TC-7510. USB ADAPTER (http://www.maplin.co.uk/Module.aspx?ModuleNo=34128).[/QUOTE]

am i to understand that one of these adaptors connected to an optical lead will allow me to achieve 24/96 output from my mac mini to the 7510 dac ?
thanks
steve

[Themis]

am i to understand that one of these adaptors connected to an optical lead will allow me to achieve 24/96 output from my mac mini to the 7510 dac ?

The description says " It supports 48KHz in digital / analog audio playback".

You have plenty of 24/96 on the professional side: I guess something like http://www.westenddj.co.uk/Product/EDIROL/DJ+Effects+and+Production/UA1X/

[StanleyB]

USB only goes to 48KHz from what I understand. However, a few companies have been using upsampling to claim 96KHz for their USB port.
You can get a PCMCIA to optical adapter card that supports 96KHz. I got one somewhere that I use for testing purposes. Works fine.

[steve dixon]

The description says " It supports 48KHz in digital / analog audio playback".
well what do you know, i remembered i have a xitel usb to toslink adaptor left over from my experiments in minidisc, i routed it out and plugged it into the back of the mac mini and hey presto usb output no questions asked, only problem is the mac mini audio out settings are unavailable which leads me to believe it's defaulted to toslink settings anyway. i'm listening as i type and my first impression is....... well there's no real difference to a straightforward toslink cable. so i guess i'll just have to buy a 7520.
still no harm done to the pocket to find out.
thanks
steve

[Themis]

USB only goes to 48KHz from what I understand. However, a few companies have been using upsampling to claim 96KHz for their USB port.
You can get a PCMCIA to optical adapter card that supports 96KHz. I got one somewhere that I use for testing purposes. Works fine.
Is that because of the USB 1.1 ? Are there any USB 2.0 audio devices, I wonder ?