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apmusson
24-07-2009, 08:28
As discussed in the original tc7520 mod thread.

I am very excited about getting the special edition tc7520 from stan soon.

This special edition tc7520 caiman has a different DAC chip from the original tc7520. This DAC chip has its own audio characteristics and may suit different opamps to the original tc7520.

This thread is to discuss mods (inc opamp replacements) for the caiman tc7520.

I have ordered the ad826 opamp to test the waters but would also like to retry some of my older opamps when the caiman arrives.

Ade

Stratmangler
24-07-2009, 08:41
I have ordered the ad826 opamp to test the waters but would also like to retry some of my older opamps when the caiman arrives.

Are you going to spend some time listening to it before whipping the lid off ?:smoking:

It hasn't landed and you're improving it already.

Just my observation:)

Chris:)

apmusson
24-07-2009, 08:45
Of course I am.

:lolsign:

I'm sure that it will be an excellent DAC in its original state.

I just wanted to create an area where people could post comments and changes rather than 'mix it up' in the old tc7520 thread.

Ade

StanleyB
24-07-2009, 08:47
Shocking what people are already planning to do this lunch time:mental:.


Stan

apmusson
24-07-2009, 08:58
I hope it arrives today. I'm very excited to try it.

I'm not planning any changes for a while - my experience is that Stans DACs are excellent in their non-modded forms and I'm looking forward to trying it 'au naturale' for quite a while. But one of the things that I love about this forum and stans DACs is the ability to mod.

Ade

Stratmangler
24-07-2009, 09:05
Fair comment about the seperate thread, I just thought the modification bit was rather "cart before horse".;)

IIRC didn't Stan say that the Caiman PSU wouldn't available for a bit, cos it needed some certificate or other ?:smoking:

Which means it's best to leave the lid on for 2 weeks after the new PSU lands.

I'm not trying to put you off, honestly :lolsign:

Chris:)

StanleyB
24-07-2009, 09:08
I hope it arrives today. I'm very excited to try it.

Out of all the DAC dealers, my speed of delivery is still the best in the world:).

Stan

link
25-07-2009, 15:05
is the caiman available now? is it available on the website?

roscoeiii
25-07-2009, 15:13
It is available now. Stan posted an announcement in "Trade Inspirations" PM him and he will send you a link.

link
25-07-2009, 15:17
ok thanks, i'm just visiting the digital impression forum and didnt notice these threads.

leo
27-07-2009, 19:02
A thread modding a ready modded 7520:scratch:

I guess just rolling a few op-amps isn't bad though:)

StanleyB
27-07-2009, 19:09
I'll be trying the LM4562HA in one once I have soldered in those cans. I am not convinced that squeezing them in a socket is doing them justice.

Stan

leo
27-07-2009, 19:09
Regarding AD826, its a very good chip in the right place, internally its the same as the THS4032, main difference is the compensation cap on the output of the AD826 ,reduced bandwidth

roscoeiii
27-07-2009, 19:15
Leo, in your experience, what are the sonic effects of the AD826's compensation cap and reduced bandwidth?

From earlier threads, the LM4562HA also came immediately to mind for me as well.

But first to sit back and listen. Then see what others have swapped in and liked. Then eventually I may get off my duff and swap op-amps myself.

leo
27-07-2009, 19:15
I'll be trying the LM4562HA in one once I have soldered in those cans. I am not convinced that squeezing them in a socket is doing them justice.

Stan

I'm still using HA, totally agree regarding soldering in place, tbh with the metal cans using pins they tend to go a little loose in the sockets causing a bit of noise on the outputs if the dac is tapped

leo
27-07-2009, 19:19
Leo, in your experience, what are the sonic effects of the AD826's compensation cap and reduced bandwidth?

From earlier threads, the LM4562HA also came immediately to mind for me as well.

But first to sit back and listen. Then see what others have swapped in and liked. Then eventually I may get off my duff and swap op-amps myself.

Helps driving capacitive loads better, may be worth giving it a go in the Headphone position too just to see how it performs, where the THS4032 had problems driving some cans (its not just the cans impedance but cable capacitance can also cause problems) the AD826 may be better suited

sponge
27-07-2009, 19:40
Helps driving capacitive loads better, may be worth giving it a go in the Headphone position too just to see how it performs, where the THS4032 had problems driving some cans (its not just the cans impedance but cable capacitance can also cause problems) the AD826 may be better suited

The AD826 is my personal favorite for the Headphone position - I could not settle with the THS4032. I have a LM4562NA in the line-out position and this combination works just fine with K701 and HD600 cans via both the 7520's HA socket and my external headphone amps.

I know the LM4562HA gets some good reports, but I'm a little sceptical how a metal can can make a noticeable difference (improvement?). Perhaps you would like to comment Leo?

If I swap just the 4562NA in the line-out socket to the HA version, will it affect the smooth AD826 sound I like from the HA socket?

Why can't we just leave well alone!! ;)


Ken

leo
27-07-2009, 21:09
The AD826 is my personal favorite for the Headphone position - I could not settle with the THS4032. I have a LM4562NA in the line-out position and this combination works just fine with K701 and HD600 cans via both the 7520's HA socket and my external headphone amps.

I know the LM4562HA gets some good reports, but I'm a little sceptical how a metal can can make a noticeable difference (improvement?). Perhaps you would like to comment Leo?

Only thing I can think of is that the metal can affects thermal matching better of the IC internally, less drift etc, it may also be tighter specced than the standard plastic version



If I swap just the 4562NA in the line-out socket to the HA version, will it affect the smooth AD826 sound I like from the HA socket?

Why can't we just leave well alone!! ;)


Ken

Stan will correct me if I'm wrong.
The line out op-amp is in series (along with the coupling caps,resistors) with the HA op-amp so if you change the line out op-amp it'll have an effect on the HA too

Give the AD826 a try in both positions, you may like it better or worse, it should work ok without issues

sponge
27-07-2009, 21:39
Thanks mate, much appreciated.

Ken

leo
27-07-2009, 23:32
No probs:smoking:

StanleyB
27-07-2009, 23:42
The choice of opamp for the headphone is very much dependent on which headphone you are using. The choice of opamp for the line out is dependent on your speakers. I have been listening to Bela Fleck and the Flecktones through the HD650 and the NS1000M. With that combination, I like the LM4562HA/LM4562NA. But when I substitute the HD650 for the K701, then my choice is LM4562NA/THS4032CD.
So the opamp pairing is not so straight forward.

sponge
28-07-2009, 08:07
The choice of opamp for the headphone is very much dependent on which headphone you are using. The choice of opamp for the line out is dependent on your speakers. I have been listening to Bela Fleck and the Flecktones through the HD650 and the NS1000M. With that combination, I like the LM4562HA/LM4562NA. But when I substitute the HD650 for the K701, then my choice is LM4562NA/THS4032CD.
So the opamp pairing is not so straight forward.

That's true about the headphone pairing Stan. But I do seem to have hit a happy compromise with the AD826. I'll not say it's a "Jack of all trades" but for my K701's and HD600's it's pretty close. If you haven't tried an AD826, give it a go.
My concern is with the line-out Opamp. The LM4562NA works well with my external head amp, but will there be an improvement moving to the HA version - Or even another AD826 (I only have one). And what effect will this have on the 7520's headphone output which I use a lot? - I don't want an overly bright sound.

What we need is a whole bank of Opamp sockets and a couple of rotary switches to select different devices - Perm any 2 from 10 sort of thing :)
Now there's a mod and no mistake ;)

Ken

StanleyB
28-07-2009, 08:13
My concern is with the line-out Opamp. The LM4562NA works well with my external head amp, but will there be an improvement moving to the HA version - Or even another AD826 (I only have one). And what effect will this have on the 7520's headphone output which I use a lot? - I don't want an overly bright sound.

Keep the rest of us in the picture with your findings:).

Stan

joshcloud9
03-08-2009, 18:17
Hi all,

I have a pair of AD797AN's on a browndog adapter and am wondering if they will be suitable for the 7520 / Caiman I have yet to buy?

I am currently using a Musical Fidelity V-DAC which I am happy with for the time being, but upon the arrival of my Nuforce IA-7 V2 shortly I will be looking at Berersford to up the anti for me!

I am presuming that the Beresford does/can surpass the V-DAC?!

Any thoughts...

apmusson
07-08-2009, 13:15
I have tried quite a few opamps on my std 7520 without a hitch, but I'm afraid I cant comment on whether the AD797 will be compatible (although the browndog adaptor will at least make it pin compatable I assume). Anyone else like to comment?




Hi all,

I have a pair of AD797AN's on a browndog adapter and am wondering if they will be suitable for the 7520 / Caiman I have yet to buy?

I am currently using a Musical Fidelity V-DAC which I am happy with for the time being, but upon the arrival of my Nuforce IA-7 V2 shortly I will be looking at Berersford to up the anti for me!

I am presuming that the Beresford does/can surpass the V-DAC?!

Any thoughts...

leo
07-08-2009, 20:17
AD797 are great op-amps, unfortunately their not really suited in this app as is, may work with a few mods, I briefly tried them but had the occasional break up/distortion

Chippy_boy
20-08-2009, 17:31
Hello, I'm new here and this is my first post, so "Hello" from me :-)

I am getting a Caiman tomorrow and have great hopes for it - let's hope I am not disappointed.

One "mod" I thought of is, would there be any mileage in running it off a 12V battery instead of the little mains adapter? I see it only draws about 100mA, so at 1.2w a Li-ion battery (or even a car battery) could power it for hours with a rock solid, high current-capable power source. Surely some improvement to dynamics and transparency.

What do you reckon?

StanleyB
20-08-2009, 17:49
Hi Mark, well a battery is possible but a few people have had less than satisfying results with batteries compared to raw mains.