CS4397 dac

[FireFly]

Some news:
Capacitors C32 and C33 (original value 56pF) should go out. Op-amp will not oscillate without them , they are killing highs.
Capacitors C34 and C35 (original value 1nF) should go out. Or minimal value of 100-150pF, as Leo suggested.
C44 and C51: desolder original 100μF, put 47μF.
C40 and C50: leave original SMD, bypass with 0.1μF MKP (small size)

Bottom side of the board:
Solder lytic capacitor 4.7μF or 10μF directly to op-amp legs 4 and 8 (4=negative, 8=positive) for decoupling. Use good quality cap.

[JDMz]

This guy did tests and proved that it Improved the highs..
http://theartofsound.net/forum/showp...&postcount=210

Removing those capacitors, are we replacing it with something else? Or just leaving it empty?

[Taro]

Hi
I'm Marco from Germany (sorry for my bad english).
My Kit arrived today.
I compared the "stock"-dac-kit with my CD-Player ( a Sony SCD-XE670).
The only difference I heared was that the DAC is a bit louder than my CDP.
I'm a bit disappointed. Is this normal in "stock"-state?

What is the first thing I could do to improve the Sound?

My equipment:
Sony CDP SCD-XE670
Amp: Rotel RA-931 (I use its headamp)
Sennheiser HD650

Thanks in advance


Marco

[Marco]

Hi Marco, from another Marco

Welcome to AOS. Where in Germany are you? My wife has relatives in Köln and Bergisch Gladbach.

Marco.

[Taro]

Where in Germany are you? My wife has relatives in Köln and Bergisch Gladbach.

Marco.

Hi Marco

I live in western Germany. About 100km to Köln and 10km to the Netherlands.

[Marco]

Hi Marco,

Are you anywhere near Euskirchen? My wife also has relatives there. We usually spend a week in Köln and a week in the countryside near where you are

I love Germany!

Anyway, we better keep the thread on topic I just popped in to say hello.

Marco.

[Taro]

Hi Marco,

Are you anywhere near Euskirchen? My wife also has relatives there. We usually spend a week in Köln and a week in the countryside near where you are

Euskirchen is in the South of Köln. I live in the North (about 100km) of Köln.

I love Germany!

Me too!

Anyway, we better keep the thread on topic I just popped in to say hello.

Yes we should. I think the others are getting nerved by this.


So could anyone make a guide/tutorial or simply a list of what improved the sound? That would be awesome!

I read the whole thread (and also this and this) but I'm a bit confused because some mods are contradictory.
One persons changes Capacitor-A like this and another like that.

Thanks in advance

Marco


P.S.: There is actually no thread in our german hifi-forum. If I suceed with my mods, I will post one.

[JDMz]

im gonna try firefly's mod when people start confirming it is good. Yea I am confused too. Leo has 4 capacitors around the opamp when firefly removes 2 of them. And he removes the resistor mods too. Leo hasn't been on in a while, but I will do the mod once he agrees with firefly lol.

[leo]

Things like PSU's and type of op-amps can cause varying results, I personally don't like Oscon caps in a lot positions yet some others do, as with everything else its best to try it out, if you don't like it, just rip it out

I've not tried removing the caps in the op-amps feedback positions yet.
I'm currently using AD826 which can be a little touchy so requires a bit of care
Soon as I get time I'll remove the caps and have a look on the scope

If you remove the the caps and notice excessive brightness this can be a sign of HF distortion caused by ringing, some op-amps shouldn't cause any issues so should be fine

[JDMz]

I have capacitors like this except 4uF on my outputs. http://www.parts-express.com/pe/show...number=027-200

It does not show polarity.. can it go any way?