Mod your Beresford 7520

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25-03-2009, 19:07
chrism

Hi Stan,

Beginner but handy with the old iron so happy to have ago. If I wreck it it will give me a good excuse to buy a 7520 ;)

Regards

Chris
25-03-2009, 19:10
rhmjmango

Getting warm!
http://search.digikey.com/scripts/Dk...me=399-4328-ND
25-03-2009, 19:12
leo

Quote:

Originally Posted by Sensimilia

A few beginners have ran into troubles:(.

Yes, its easy to end up with a knackered dac
25-03-2009, 19:16
sponge

Quote:

Originally Posted by rhmjmango

Talking about a 0.1uF ceramic cap. I do not know what to look for on the farnell website. Can anybody help me out? Thanks!

Try part no 114-1775 from Farnell - Good quality Vishay cap at 35p for 5 :)

Ken
25-03-2009, 19:20
chrism

Am I right in thinking that Farnell is £20.00 min order or am I reading the small print wrongly. RS online does not appear to have this though.

Regards

Chris
25-03-2009, 19:21
leo

Quote:

Originally Posted by sponge

OK, here goes:

http://farm4.static.flickr.com/3459/...1e61ee3e_m.jpg

Sorry about the photo quality.
Here is the mounted and modded chip installed in the DAC.

Ken

Nicely done there Ken! should help prevent any issues
25-03-2009, 19:24
leo

One thing to remember if others are fitting the ceramics, don't over heat or sharply bend the legs, these caps are pretty fragile
25-03-2009, 19:39
drumlins4ever

As an idea
I think it may be interesting after a month or so when everyone has become acquainted with the various opamps to run a favorites poll.
25-03-2009, 19:41
HighFidelityGuy

Quote:

Originally Posted by Sensimilia

There is. It's the one marked MLC10 in the picture posted by Ken:). But the specs recommend that the 100nF is as close as possible to pin 4 and 8. So that's what the '0.1mF mod' is all about;). You are adding a 100nF as close as possible to pins 4 and 8. The one on the main PCB is not close enough once you start adding an adapter PCB. The distance from say pin 4 on the surface mount IC and the appropriate leg on MLC10 is now several mm longer. And that extra track increase is suddenly an obstacle/nice short length of RF aerial. Putting an extra cap in circuit and closer to the chip even things out again.

STan

Thanks for taking the time to explain that so thoroughly, it's really helped me understand what the cap is for. :)
25-03-2009, 19:46
sponge

Quote:

Originally Posted by chrism

Am I right in thinking that Farnell is £20.00 min order or am I reading the small print wrongly. RS online does not appear to have this though.

Regards

Chris

You are probably right at that - Welcome to the world of DIY electronics! ;)

Ken
25-03-2009, 19:54
Covenant

Any one fancy a group buy for the THS4032 as its a minimum £20 order?
25-03-2009, 19:58
Getgaff

Quote:

Am I right in thinking that Farnell is £20.00 min order or am I reading the small print wrongly

No minimum order for me - just ordered 5 x 114-1775 for £2.07 inc vat and delivery.
25-03-2009, 20:00
Getgaff

Quote:

Try part no 114-1775 from Farnell - Good quality Vishay cap at 35p for 5

£0.36p each - minimum order of 5.
25-03-2009, 20:11
sponge

Quote:

Originally Posted by Getgaff

£0.36p each - minimum order of 5.

Ooops, sorry - I'm going to have to start wearing these specs!!

Ken
25-03-2009, 20:13
fault151

Guys anyone have a link to buy a LME4970HA op amp,i looked on ebay buy said nothing available.
25-03-2009, 20:29
freddiecas

if you already have a LM4562 in your 7510 6/4 Mod 21 part 2 is it worth changing it for a THS4032?
25-03-2009, 20:32
Getgaff

Quote:

Guys anyone have a link to buy a LME4970HA op amp,i looked on ebay buy said nothing available.

This the seller I used,

http://cgi.ebay.co.uk/ws/eBayISAPI.d...&Category=3272
25-03-2009, 20:32
leo

Quote:

Originally Posted by fault151

Guys anyone have a link to buy a LME4970HA op amp,i looked on ebay buy said nothing available.

http://cgi.ebay.co.uk/LME49720HA-OPA...1%7C240%3A1318
25-03-2009, 20:33
leo

Snap:lol:
25-03-2009, 20:37
Getgaff

:doh:
25-03-2009, 20:56
HighFidelityGuy

Ah I was wondering why I couldn't find any info on the LME4970HA, it's actually the LM4562HA, how odd. :scratch:

They're £20.30 from Farnell, so that ebay source is nearly 50% cheaper. Nice find!
25-03-2009, 21:48
kalozois100

Quote:

Originally Posted by freddiecas

if you already have a LM4562 in your 7510 6/4 Mod 21 part 2 is it worth changing it for a THS4032?

This is definately a question i would like answered too as i also have the above mods you mention in the 7510..........yeah is it worth it or not? :confused: The LM4562MA already seems a very good performer.
25-03-2009, 22:08
StanleyB

Quote:

Originally Posted by kalozois100

This is definately a question i would like answered too as i also have the above mods you mention in the 7510..........yeah is it worth it or not? :confused: The LM4562MA already seems a very good performer.

The THS4032 is far more of a performer in the TC-7520. I wouldn't advise carrying out any more surgery on the PCB through a repeat removal of the TC-7510 opamp. Disaster possibilities such as track damage are higher than 66.6%. On a fresh PCB you stand a better chance of success.
26-03-2009, 11:33
HighFidelityGuy

I've just ordered a pair of LME4970HA's and some of the adapter boards needed for the THS4032. I'll be ordering the THS4032 form Farnell at a later date along with some other bits I need for other projects I'm working on. I'll let you all know what I think to them.
26-03-2009, 11:53
sponge

Oh no - I seem to have a problem. :(

Last night the TC-7520 headphone amp with THS4032's was playing fine, so I replaced the cover and left the unit playing with a looped CD into my K701's.

This morning when I had a listen, I hear a VERY faint "crackle" on quiet passages - Only when music is playing and not noticeable on louder passages. It's not the source as the same thing happens when playing the same track via CD (optical) or Squeezebox (coax).

I suspect a bit of instability with the THS4032's - But which one?

Perhaps Stan can help here - I am aware the 4032 is not unity gain stable so maybe this cannot be fixed if one of the opamps is acting as a buffer. Pity really as I love the THS4032 sound signature.

Have any of you guys trying the THS4032 noticed anything similar?

Ken
26-03-2009, 12:14
kalozois100

Quote:

Originally Posted by Sensimilia

The THS4032 is far more of a performer in the TC-7520. I wouldn't advise carrying out any more surgery on the PCB through a repeat removal of the TC-7510 opamp. Disaster possibilities such as track damage are higher than 66.6%. On a fresh PCB you stand a better chance of success.

Statistics always get my attention Stan!! - and i hadn't realised the risk for repeated opamp changes although i am kicking myself I didn't install an adapter for opamp rolling for the 7510 at the time of changing the opamp . Still it sounds very good as it is so i am thankfull the mods went well with no side effects. one suggestion for 7520 owners is how much i like the audio signature of the black gate caps in the mods for the 7510 that the LM4562MA drive. Is this feasible for the 7520 aswell??
26-03-2009, 12:50
HighFidelityGuy

Quote:

Originally Posted by sponge

Oh no - I seem to have a problem. :(

Last night the TC-7520 headphone amp with THS4032's was playing fine, so I replaced the cover and left the unit playing with a looped CD into my K701's.

This morning when I had a listen, I hear a VERY faint "crackle" on quiet passages - Only when music is playing and not noticeable on louder passages. It's not the source as the same thing happens when playing the same track via CD (optical) or Squeezebox (coax).

I suspect a bit of instability with the THS4032's - But which one?

Perhaps Stan can help here - I am aware the 4032 is not unity gain stable so maybe this cannot be fixed if one of the opamps is acting as a buffer. Pity really as I love the THS4032 sound signature.

Have any of you guys trying the THS4032 noticed anything similar?

Ken

Hmm, that's a bit worrying. Perhaps they are over heating? Would it be possible for you to check how hot they are and report back?
26-03-2009, 13:06
sponge

Quote:

Originally Posted by HighFidelityGuy

Hmm, that's a bit worrying. Perhaps they are over heating? Would it be possible for you to check how hot they are and report back?

Well, I have the cover off the TC-7520 at the moment and the chips are well within their temp range - Only warm to the touch and the unit has been powered up for quite a while.

This is so annoying as the sound (to my ears) is superb - It drives the K701's effortlessly.

Ken
26-03-2009, 13:44
Covenant

Could you swap back the old op-amps just to make sure its not something else?
26-03-2009, 13:58
HighFidelityGuy

Thanks for the update.

I've just been comparing the THS4032 with the original NE5532 and I noticed that the NE5532 needs up to +/- 22V while the THS4032 only needs up to +/- 16V. I don't know if this has anything to do with it. I guess it depends on what voltage the 7520 is giving the chip. I guess Stan is the best person to answer this. Any idea what's causing this Stan?
26-03-2009, 13:59
sponge

Quote:

Originally Posted by Covenant

Could you swap back the old op-amps just to make sure its not something else?

Yep, tried that already - Problem goes away with the original 5532's.

Just noticed something else - When the Squeezebox changes tracks, I hear a slight "click" in the phones - This didn't happen with the 5532's.
26-03-2009, 14:08
sponge

Quote:

Originally Posted by HighFidelityGuy

Thanks for the update.

I've just been comparing the THS4032 with the original NE5532 and I noticed that the NE5532 needs up to +/- 22V while the THS4032 only needs up to +/- 16V. I don't know if this has anything to do with it. I guess it depends on what voltage the 7520 is giving the chip. I guess Stan is the best person to answer this. Any idea what's causing this Stan?

Those voltages are the maximum - The minimum working voltage is considerably less - 10V (+/- 5V) for the THS4032 for example.

Ken
26-03-2009, 17:55
trailer

Well I've had the LM49720's in for a day now. Took a bit to get them running I think. More so than the 4562's and I suspect they might not be fully ran in yet.

Compared to the 4562's they are more revealing of the recording. More clinical I would say. Some recordings I think "much better", then others are a bit "erm, OK". Like I said I think this might be due to the revealing nature of the 49720's and the quality (or lack of) of the recording.

I'm going to persevere. (And I might get some 4032's :cool: )
26-03-2009, 19:00
rhmjmango

Some people on the web like the LME49860 very much so i had a look at the catalog of National.

http://www.national.com/cat/index.cgi?i=i//305

I wonder if the specs. of this opamp make it possible to use in the 7520.
Can anybody comment on this opamp?

Oke i've found the answer, i read they have the same quality specs as the the LM4562! Just higher voltage loads.
26-03-2009, 20:02
HighFidelityGuy

Quote:

Originally Posted by rhmjmango

Some people on the web like the LME49860 very much so i had a look at the catalog of National.

http://www.national.com/cat/index.cgi?i=i//305

I wonder if the specs. of this opamp make it possible to use in the 7520.
Can anybody comment on this opamp?

Oke i've found the answer, i read they have the same quality specs as the the LM4562! Just higher voltage loads.

It appears to be pin compatible so I think it should work. The LME49860NA version would be the one to go for as it's the right package type.

Farnell sell it HERE

The specs seem almost the same as the LM4562 and the LME49720 but the LME49860 has a higher max voltage rating.
26-03-2009, 23:53
Stratmangler

Quote:

Originally Posted by Stratmangler

I am more than pleased with the results though - music just "sounds right".
Music sounded good before the mods, but the whole mod21 thing has lifted my 7510 up into a different league.

I should have learned by now to keep my mouth shut by now - I keep on forgetting (sign of stupidity, maybe ?) - but I keep getting caught out by the running in period required by components.

I've had the 7510 with the recently done Mod21 stage2 upgrades running for 48 hours or so, and the sound has gone from brilliant to ok, defined to grungy, generally great to good to passable to poor, and back again, sometimes within the space of an hour.

As I am typing things sound fantastic, but I am expecting a change for the worst before things eventually stablise and bed in.

Here's hoping for stabilisation sooner, rather than later:cool:

Chris:)
27-03-2009, 09:50
mwahahaha

Just a little confused from trying to combine all the info on the THS4032's - in order to use these you need an adaptor board but do you also have to solder in an additional cap?

Cheers
Dan
27-03-2009, 10:00
tizer2000uk

I have noticed clicks and pops on various tracks with the LM4562's (MP3's) With lossless files I dont have any problems. I think any anomalies on tracks might be due to them being bad recordings and the LM4562's ability to dig up alot of detail.
27-03-2009, 10:01
trailer

Quote:

Originally Posted by mwahahaha

Just a little confused from trying to combine all the info on the THS4032's - in order to use these you need an adaptor board but do you also have to solder in an additional cap?

Cheers
Dan

Aye.
27-03-2009, 10:04
mwahahaha

Cheers Trailer much appreciated.

Think I might start with giving some LM4562's a go and see how I get on from there:)

Cheers
Dan
27-03-2009, 10:23
trailer

Quote:

Originally Posted by mwahahaha

Cheers Trailer much appreciated.

Think I might start with giving some LM4562's a go and see how I get on from there:)

Cheers
Dan

No problem. Make sure you get the LM4562NA.

http://shop.ebay.co.uk/merchant/yp53...Q_fromZQQ_mdoZ
27-03-2009, 10:26
mwahahaha

Will do, Cheers!:)
27-03-2009, 15:27
chrism

LM4562NA for the 7520 and LM4562MA for the 7510 - just to be clear.

Any news on the problem reported with the THS4032 - I am waiting to buy one.

Regards
27-03-2009, 16:01
sponge

Quote:

Originally Posted by chrism

Any news on the problem reported with the THS4032 - I am waiting to buy one.

Regards

I's still awaiting some feedback on the problem - I am living with it at the moment as the sound is so good, but it niggles and is a bit distracting.:(

Ken
27-03-2009, 16:04
trailer

Have you both got the Pin4/8 cap fitted?
27-03-2009, 16:07
sponge

Quote:

Originally Posted by trailer

Have you both got the Pin4/8 cap fitted?

Yes - See post #43.
27-03-2009, 16:14
trailer

Ok, I'm getting some 4032's next week.

I've been listening to the 49720's again this afternoon. That's 48 hours in the 7520 now.

Firstly things seemed to have changed for the better. A definite improvement on the 4562's. Bass is deeper and there is much more detail and clarity of individual instruments. Not quite as big a soundstage but I'm being picky on that one.
27-03-2009, 16:18
Covenant

Just a suggestion (and I know nothing about electronics)-could you get hold of another THS4032 and try it without the capacitor. That would tell you if its been damaged by heat when soldering or possibly a dry joint is causing the crackling.
27-03-2009, 16:56
sponge

Quote:

Originally Posted by Covenant

Just a suggestion (and I know nothing about electronics)-could you get hold of another THS4032 and try it without the capacitor. That would tell you if its been damaged by heat when soldering or possibly a dry joint is causing the crackling.

OK, that's a thought - I have a spare chip and some BrownDogs - I'll give it a try. As a matter of fact, if I swap the two opamps around, the crackling gets a little worse, which could suggest one of them is a bit iffy.

Thanks for the suggestion - I'll keep you posted.

Ken
27-03-2009, 17:04
rhmjmango

I will also roll in a LME49720HA to find out the difference with the LM4562HA.

I saw this seller on ebay.
'We recommend using Black Gate (or similar) capacitors on the power rails for these opamps'.
I wonder if he means connecting pin 4 and 8 with the fore mentioned cap.

http://cgi.ebay.co.uk/LME49720HA-LM4...3A1|240%3A1318

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