Caiman Mods

Quote:

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Originally Posted by chrism

Does anyone know why non polarized caps rather than polarized ones would offer upgrade to the opamp circuit? I thought that the non polars are just two caps back to back effectively. Is it more likely that the improvement in sound could be just down to a different cap?

Regards

Chris

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I too was wondering this.

I have, however, bought a load of the 47uF 16v non-polarised caps that stan recommended. Just awaiting their arrival then I shall get stuck in with the soldering iron.

http://www.homehifi.co.uk/images/mods/caiman/caps.jpg

From left to right:
1. The standard PCB.
2. One fitted with the LM4562HA,
3. And the one I prefer for my headphones: the THS4032CD

Only 6 polarized caps should be replaced. Leave the others well alone. They are for the bias of the headphone amp.
Also replace the two yellow caps either side of the headphone opamp from 47nF to 68nF.

Looking good Stan:smoking:

Quote:

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Originally Posted by StanleyB

http://www.homehifi.co.uk/images/mods/caiman/caps.jpg

From left to right:
1. The standard PCB.
2. One fitted with the LM4562HA,
3. And the one I prefer for my headphones: the THS4032CD

Only 6 polarized caps should be replaced. Leave the others well alone. They are for the bias of the headphone amp.
Also replace the two yellow caps either side of the headphone opamp from 47nF to 68nF.

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Perfect, I shall give this a go.
I have 30 of the non-polarised caps on their way to me, I should also have 5 THS4032CD's & 5 OPA2132's on their way too me as well. All I need now are the 2 WIMA caps, and some SOIC to DIP pcbs and im ready to go.

Just a thought Stan, is it possible to get a second Op-Amp PCB with components? One for playing with or modifying and the other for a base comparison. Then maybe it would be possible to just switch the entire PCB to perform side by side tests of component combinations. :eyebrows:
Mind you, I'm sure that's what you do anyway... :lol:

I know what I am doing this weekend :)

Can any of these alterations be applied to the 7520 Stan? (and is it worth it)

They work fine on my TC-7520 as well.

Stan,

Looks good.

Following your testing do you prefer the LM4562HA (metal can) opamp to the standard LM4562's (plastic) for the line out circuit?

Regards

Chris

I have always preferred the THS4032CD for my system, and matches the combination of NS1000M & HD800 perfectly for me.
The LM4562 metal can type has more bass than the plastic version, but less detail and less treble, when used on my system.

The one on the right hand side looks quite interesting.

Two questions;
1) Where are the two yellow caps at the very top of the PCB attached to? The same place the blue ones are in the middle one?

2) Do these changes counteract the highly-strung needs of the THS4032CD? There is quite a lot of sibilance / frequency misrepresentation with them in the unmodified circuitry.