What makes the most sound improvement?

[till]

most sound improvement

The bottle of wine you drink at the evening you test your new diy amp after its finished for the first time with real music.

[TimA]

……but where to from there???

Steve,

Some suggestions based on my own experience.

General…
Replace the volume pot with an attenuator (shunt type).
Upgrade the electrolytics.

With reference to reducing harshness.
Cheap electroylics sound congested and harsh, use film types where possible, preferably Jensen paper-in-oil.

Buffer…
I have repeatedly tried the OPA627 (and many other OPA/AD op-amps) in two different circuits (in, and not in, class A). I have consistently formed a preference for the AD797, NE5534, NJM2114 and the LM6171 due to their more natural presentation of detail. For striking dynamics, excitement and thrills the OPA627 is perhaps a better choice, along with many other FET input op-amps, though to my sensitive ears most of the FET types sound hard and edgy to some degree. The AD6810 and the AD825 are exceptions. For tonal accuracy, smoothness and fine detail try the LM6171 in class A, though fit a 500nF film cap across its supply pins, though don’t expect much in the way of ambient warmth. For that try the NE5534 which improves on all of the above with respect to fine ambient detail, or the AD797. For many I am sure the NE fails to provide excitement and it certainly sounds less dynamic than most, but it somehow manages to extract all that is good in a recording whilst removing the rest. Or should that read ‘it doesn’t add anything of its own’. For best results perhaps you could omit the NE5534 compensation capacitor and configure the circuit for some gain. The NE5532, which has the compensation capacitor built-in, sounds less good in my circuit.

Tim.

[BlackDog]

Originally posted by TimA
……but where to from there???


Replace the volume pot with an attenuator (shunt type).

You mean a stepped attenuator...or something else?

Upgrade the electrolytics.

I'll be ordering some Panasonic FC's for the supply caps soon.

With reference to reducing harshness.
Cheap electroylics sound congested and harsh, use film types where possible, preferably Jensen paper-in-oil.

Buffer…
For best results perhaps you could omit the NE5534 compensation capacitor and configure the circuit for some gain. The NE5532, which has the compensation capacitor built-in, sounds less good in my circuit.

Tim.

I quickly built a buffer onto breadboard last night, using an NE5534 and decided to follow the circuit Nuuk has on his website, without any unity gain compensation. It worked (ie I got sound) , but I haven't had a chance to listen to it properly yet. It'll have to wait 'till I get back from my hols to play with it more.

Steve

[TimA]

Steve,

Yes, I mean a stepped attenuator.

Tim.

[Nuuk]

Yes, he means a shunted stepped attenuator.

Read this Steve.

[matjans]

apart from the volume control and electrolytics, using quality resistors (especially in the feedback loop) improves the sound too.

Try Caddock mk132's, if you can get'em. To me they sound very natural and detailed, the soundstage is much wider than with normal metal film resistors. Expensive though...

[maylar]

Riiiiight.

Better use pure silver wire too. Doesn't distort those electrons like copper does.

[matjans]

... and all interlinks sound the same.

you could ofcourse *try* it...

[matjans]

hah i found the thread i was looking for: link

people talking about the sound of caps & resistors.

[BlackDog]

Thanks for all the suggestions guys.....

Can't say much more as I am holiday, and this is just a brief trip to a net cafe...

Steve