CS4397 dac

[alb]

This is how my version of this DAC looks when hooked up to a Lampizator style tube output stage.



Another pic showing updates to the DAC mainboard. Getting rid of a few surface mount parts and replacing with quality capacitors. Seems to have paid off. Still work in progress though.

[Filterlab]

Very nice indeed.

[iihay]

Sorry I'm late chaps, been busy and not had a lot of time

Currently still using the modified op-amp based output stage but got another one of these cheapo dacs so will try the Lampizator output stage on this one to compare

Theres only so much you can do with these dacs but it makes sense to get as much as you can out of them.
I'm still playing about with the decoupling, again the dac is limited because of the layout, I'll post more info as soon as I can

Cool, I'm not ready to tinker yet anyway got a humm on my amp to resolve first, causing me some significant grief

Interested to hear more.

Cheers

Iain

[leo]

A few very simple things to try first if you intend on using the standard op-amp based output stage, don't expect giant killing performance but its not too shabby IMHO for a dirt cheap thing

Recommending a specific capacitor type is hard for the decoupling, it mainly depends on what regulated PSU your going to be using, just be careful if using lots of low ESR caps and check for instability

For any op-amp you want to try carefully check the datasheet first to make sure its suitable

[jonners]

This is how my version of this DAC looks when hooked up to a Lampizator style tube output stage.



Another pic showing updates to the DAC mainboard. Getting rid of a few surface mount parts and replacing with quality capacitors. Seems to have paid off. Still work in progress though.

alb - you seem to have soldered the replacement through-hole components very close to the board, and I'm wondering how you managed to do that so well?
The boards supporting the valves look very cool - can you tell me where I can get some like those please?
Thanks, John

[lurcher]

The boards supporting the valves look very cool - can you tell me where I can get some like those please?

http://www.hificollective.co.uk/comp...onnectors.html

And scroll down

[alb]

Hi John.

you seem to have soldered the replacement through-hole components very close to the board, and I'm wondering how you managed to do that so well?

The photo angle makes them look closer than they actually are. However, i did make an effort to keep the leads short as possible. My solder station has an iron with a long and quite thin pointy tip, that will get underneath em.

The Glasshouse tube mounts are useful, as they bring all connections to the top. Makes access much easier when swapping bits around, which one inevitably does.

[jonners]

Thanks, alb and lurcher. Now I just need my CS4397 board - coming on a very slow boat from China, I think.

[nickthevoice]

Do you had same value capacitor for all ?

nichicon Muse FG 1000uF is a great value for C19 or more bigger ?

you bypass SMD by MKP capacitor with same value ?
because BYPASS create 2 time the original value (2uf // 2uf = 4uf)


Thanks in advance.

nicK

[alb]

Nick.

I just used caps and values that i already had in my parts box.
C19 is Pana FC 1000uf, C21 is Pana FC 150uf.
The gold Samwha caps are 220uf and the Oscons 150uf.
The cream grey box caps are 0.22 polyester and are probably not ideal.

I have already changed C9 (input cap) from .22 polyester to a .47uf Obbligatto which is much much better, although way too big to fit on the board.

Please don't think that this random assortment is my best combination. To find that, could take some considerable experimentation.
However, what i have ended up with is still a significant improvement on the unmodified board.
Lots more work to be done yet, and always open to suggestions.