What improvements to the sound quality does the WM8716 make?Quote:
Originally Posted by Sensimilia
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What improvements to the sound quality does the WM8716 make?Quote:
Originally Posted by Sensimilia
Originally Posted by Covenant http://theartofsound.net/forum/image...s/viewpost.gif
So we have a new kid on the block, the LT1364.
One of the mods or Stan should tell us if its suitable-some details:
GBP 70MHz
Slew-Rate 1000V/μs
Supply Voltage ±2.5 → ±15V
Package SOIC8
CMRR 76dB
Function Unity-gain stable, voltage-feedback
Operating Temperature Range -40 → +85°C
Settling time ns to % 50 → 0.1
V Offset mV 1.5
So what are you saying Stan.:scratch: Do you expect problems using this opamp in the TC-7520? Should i give it a try?Quote:
Originally Posted by Sensimilia
None I can think of. But a lot of people want the latest DAC chip before they part with their money;).Quote:
Originally Posted by HighFidelityGuy
I expect problems. Slew rates of 1000V/uS are sources of HF oscillation. I stay away from those high speeds when it comes to audio circuits.Quote:
Originally Posted by rhmjmango
Ah, I see. Personally I don't mind as long as a good chip has been used and most importantly it's been implemented properly. I'll stick with the existing one. Thanks. :)Quote:
Originally Posted by Sensimilia
My pair of LME49720HA just arrived. It looks like it's going to be a bit tricky to attach the 100nF cap but I'll see what I can do.
Does it matter if one of the cap's legs touches the metal can?
I'm not using the cap on my 49720's.Quote:
Originally Posted by HighFidelityGuy
Please correct me if I am wrong about this. The LME49720HA does not require a cap because it is not separated from the socket by an interface board. The capacitor that is already fitted is adequate.
That's what I thought. Hence no cap.
Hmm, when I asked a few days ago if all of the replacement opamps would benefit from the cap, Stan said yes. Could you please clear this up Stan?
I suggest that you refrain from doing any sort of repairs or mods if you are not familiar with the requirements regarding opamp power supply decoupling.Quote:
Originally Posted by HighFidelityGuy
For reference, see the manufacturer's datasheet of the component you intend to use, and also read up about it ' The Art Of Electronics' by Horowitz and Hill.
Stan
Pssst Leo-can you help here?:mental:
The guy who is soldering my THS4032CD to the 'SOIC to DIL' boards wants to know whether I need round or square pins (see email below)Quote:
Originally Posted by apmusson
"We can supply them with round or square pins.
Round is smaller & allows them to be plugged into a turned pin IC socket but
on some plugboards the round pins sre too small to be reliable on the
plugboard & need to be plugged into a turned pin IC socket which in turn is
plugged into the breadboard. Square pins are ideal for plugging into a
breadboard but are too big for a turned pin IC socket. They can be forced
into a leaf spring IC socket but it's not an elegant solution.
Which do you want. Square(0.9mm diagonal) or round (0.5mm diameter)?"
Can anyone advise which I need? I assume its the round pins?
Thanks
Ade
OK, the pins on the BrownDog adapter I have used are 0.5mm round. Hope this is what you need.Quote:
Originally Posted by apmusson
Ken
Thanks Ken. Thats just what I needed to know.Quote:
Originally Posted by sponge
I'm afraid I can't offer any solid answers because I don't own the TC-7510 or 20 so don't know how any of these replacement op-amps react in this particular unit, all I can do is offer advice on things maybe worth tryingQuote:
Originally Posted by Covenant
For all op-amps I try in any of my own gear I check for instability/oscillations,temp issues or any nasties, read the spec sheet to make sure its at least got half a chance to work in the particular application
Some of the faster higher bandwidth types like video rated op-amps usually require much more care and tend to be less suited as a drop in replacement, sometimes they will work fine yet sometimes require additional work, it may sound ok for a while but that does not guarantee its not suffering from some HF oscillation
Some op-amps are also not suited to be used at unity gain
LM4562 is a device rated for Hi-Fi audio and its unity gain stable, of course care should still be applied but you have more chance of getting stable results with this one than some of the other higher spec types
Without droning on too much more :doh:
I think the metal can LM4562 should be ok ,the onboard bypass ceramic should be adequate and should not need an additional one, looking at the pic apart from the socket the cap looks close to the pins(unless theres some weird long track) , ideally (If it was me) if the thing measures ok and I was sure this op-amp is the one I want to keep not wanting to try others I'd go as far as removing the DIL socket and soldering the op-amp direct to the pcb.
Thanks Leo,
Assuming an op-amp did cause HF oscillation would removal and replacement with a more basic one solve the problem or is it possible to do permanent damage?
Thanks guys, I'll leave the caps off for now and see what happens.
I've formed and trimmed the legs of my 49720's to make them as short as possible and I'll fit them tonight. I'm going to borrow an antistatic wrist strap and mat from work just to be on the safe side.
The wife's working late tonight so I get lot's of uninterrupted listening time. Perfect timing. :cool:
Quote:
Originally Posted by Covenant
Depends, mainly the damage would be to the op-amp internally, if an op-amp starts to suffer from bad oscillation it will over heat, continued use whilst over heating can make the op-amp go noisy, sound distorted or hissy.
Problems to the circuit outside of the op-amp can be things like burnt resistors, damaged regulators etc, if the op-amp oscillates it can put much more strain on the supply, causes the whole thing to ring like buggery
Some cases the thing feeding the op-amp or being fed from the op-amp may get damaged, things should be better protected though if input and output coupling caps are used
I've been running 4562's and 49720's for a week each, with no cap, constantly with no issues.
I'm afraid you are the guinea pig then Trailer!
If you experience any problems please report back asap.
Aye,
"NOW YOU TELL ME!!"
Daaaaaaaaaaaaaaaaad!!!!!!!!!!!!!!!!!!!!
Somebody needs to make a FAQ or sticky thread;)
OK well the 47920's are now in - bit of a struggle straightening the legs to get the little buggers in the sockets but I got there eventually!
One thing - how hot are they meant to get? After a couple of minutes the one on the right if you're looking at the DAC from the front was very hot to touch after I unplugged the DAC just to check they were both securely seated.
cheers
Dan
No idea. I just put the lid back on. Nothing on fire as of yet. How are you finding the sound?Quote:
Originally Posted by mwahahaha
A little leaner as you found although I think that is because there's more going on at the top end which is good. A more spacious sound than the original. Not a "night and day" change but I didn't expect that at all - just a refinement of what was there already.
Overall - a very happy camper!
I found that they took a good few days to settle down. I don't know why. Maybe it was just me getting use to them, but they certainly get more refined. And the bass is LOW
I've had my 47920's installed for about an hour now with the DAC playing through my amp and my headphones to run both opamps in and they are only slightly warm to the touch. Perhaps this is something to do with the impedance of your headphones if they're quite high or low or something? :confused: I don't know much about driving headphones as I prefer not to use them.Quote:
Originally Posted by mwahahaha
On the subject of the 47920's, I'm liking the sound so far. I've not noticed a massive difference yet but I think that's because my speakers aren't good enough to make a critical comparison. I should be getting some new ones soon though.
I have noticed a little more detail overall and more punch to the bass.
with the LM4562NA I found an obvious and immediate difference.
As in different sound signature kind of difference.
As time went on it became better and better (and more different from the original sound)
Agree that a sticky about best Op Amp to use, various mods would be good. Perhaps even a Poll or two?
Aye I went from the 4562s to the 47920s so the night and day wasn't there as going from the 4562s from the standards. I'm looking forward to seeing how the 4032s sound in comparison though.Quote:
Originally Posted by Gazjam
I've just noticed that due to the 47920's being taller than the original opamps, they may slightly touch the inside of the lid when I replace it. Is this bad?
If it's bad all put a strip of insulating tape under the lid. If it doesn't matter, I may put a blob of heatsink paste on top of each one to help them dissipate heat through the case.
I've ordered the 4562s and the 4032s. I will get them both in time for the weekend. Which ones should I start with? Stan mentions using both types (one in each IC socket). I might do the same - use the 4032 for the headamp and the 4562 for the static line out circuit and route that through my Graham Slee Solo Headamp.Quote:
Originally Posted by trailer
What do you think?
Ade
Oh god now you've got me worried! Might check them again after I get home tonight see how they are:confused:Quote:
Originally Posted by HighFidelityGuy
I don't use headphones so that doesn't explain it? Maybe I damaged the opamp whilst installing it and that has resulted in the heat? I'll compare them both when I get home.
Personally, I'd try swapping the opamps around - ie. the one in socket 1 swap with the one in socket 2 and vica-versa and see if the problem moves with the opamp. If it does then check there isn't a short circuit to the can with one or more of the legs. If that's clear, pop the original 5532 in the hot opamp socket and observe again.Quote:
Originally Posted by mwahahaha
Ken
Hmm, according to Stan the opamp an the right is for the headphone output, so something doesn't seem right. Saying that, the one on the right is slightly warmer than the one on the left in mine but then I have headphones connected. I'd definitely do what Ken said to be on the safe side.
Just got home and whipped the lid off and all was well. I reseated the hot amp before I went out and maybe I hadn't got it in 100% correctly. Anyway just rolling a few tunes through the dac and will unplug everything and have another check before I go to bed.
I don't use the headphone amp anyway (Yet!) so only really need the one anyway if one is damaged.
OK well after a few mins of tunes the headphone amp opamp is very hot again.
I've taken it out and put one of the original ones back in just as a control.
The main opamp is fine though so perhaps I have a dud? I'll see how the original fares after 10 mins or so.
Best £10 you have spent Gaz?Quote:
Originally Posted by Gazjam
Just installed my 4562s. My first listen (20 minutes - quick test) left me with a smile on my face. The 4562s seem to create a more 'solid' sound (drums had more depth) and also an improvement in separation. I shall carry on testing them for a few days and then try the 4032s on the heapamp circuit.Quote:
Originally Posted by Covenant
Big improvement for £10 imho.
Ade
Once the original opamps are replaced for the LM4562 or THS4032, the TC-7520 ends up having one of the best non-discrete output stages in a DAC out there.
Dunno,Quote:
Originally Posted by Covenant
there was that Belgian hooker that one time...... :eyebrows:
and it was 8.99, so even better.
Was that EURO or Belgian Francs?Quote:
Originally Posted by Gazjam
LM4562NA (x2) arrived this morning.
10 minute job (mostly ensuring the kitchen work surface was as dust free as possible with a clean microfibre duster and finding my old antistatic wrist-strap and attaching it to the earth connection under the sink and getting the little plastic cap from the TC-7520 box to cover the exposed fibre optic connector).
Swapping the opamps was very easy due to the sockets (thanks).
All connected back to the hifi and the bass improvement was immediate. Nothing subtle. I spent an hour or two listening to 'Sinatra at the Sands' and Pearl Django and Bucky Pizzarelli. (iTunes Lossless and 256kbps AAC via USB from laptop system.)
Now I am watching the Sopranos episode "Mr Ruggerio's neighborhood" from season 3 (the one with the great mixture of Mancini's "Peter Gunn" theme and "Every Breath you take" by The Police) with my Panasonic DVD/HDD recorder connected via optical cable to the DAC.
Finer detail and better bass. It has not lost the class-A type character that I so enjoy with the TC-7520.
I will not be doing any further upgrades. I like the neatness of the Beresford supplied PSU and dislike the size and look of the Maplin unit. (Looks tacky and is too big with more wires.)
I am certainly not going to start soldering anything. No experience or training.
I have been urged by 'Gazjam' (in another forum) to wait for the new opamps
to run-in. They sound fine right now so if they get better then that is a bonus. The rest of the TC-7520 has been playing for many hours every day for almost 2 months so I am sure it is 'run-in' by now. I honestly cannot say I listen for such things.
As someone said, it is all about the music. The nicest thing about the TC-7520 so far has been the way it disappears. (Even my wife loves listening to the Archers on Freeview radio via the DAC or the Omnibus repeat on iTunes and likes how natural and easy and open it sounds. I won't tell her about the upgrade and see if she notices anything different in the next few days.)
Just consider that you would have had to send the DAC away and fork out at least 200 quid before you could get a set of LM4562 fitted to the DAC of one of my nearest priced competitors:eyebrows:. And after spending at least £400 for that DAC plus its upgrade I have not yet come across any A/B tests that puts the performance of the TC-7520 below it, or any other DAC for that matter. The only mention of sorts is that done my JLAND100 about his 3 box solutions DAC.Quote:
Originally Posted by chebby
http://rockgrotto.proboards.com/inde...0&page=1#47590
Crappy review of the 7520 by a Cyrus fan. As usual price not a factor.
The shocker was that some of them were modified, but he had no idea which ones. Is it the same Cyrus DAC that was judged to be not much better than the TC-7510 by a well respected HIFI magazine not so long ago?
I wouldnt know Stan as its about two years since I bought a hifi mag! Much more information on forums such as this. As you said he just casually throws in the fact that some of the dacs are modified but he doesnt know by whom, what was done and how much was spent.
The sad thing is many people will go and spend too much money on an inferior product as a result.
Over the last few weeks i have been testing the following opamps with the 7520.
LM4562NA
OPA2132PA
OPA2134PA
And have decided to stay with the LM4562's, put them back in today, the others are very nice too but i just love the 4562's soundstage, presence and bass .
Proac 110
Harman Kardon HK680
Beresford TC-7520
Airport Express / Macbook
CA 640C Azur
I have installed one LME49720HA today and got terrible distortion. Sounded like the PA at a working mens club after ten pints of Guiness.
Thought I had done something wrong and put back the 4562-brilliant sound.
Is it possible I have a duff one?
I have gone back to the original opamp in the headphone section and the 49720 in the line section as the other 49720 was getting really really hot I didn't want to leave it in and risk damaging the dac.