'noodle' dac (ebay special)

[gurusan]

ok...well if not just to learn something, how would I go about getting the 5V out more stable?

[Nemo de Monet]

It's really fairly pointless, but you could use something like Texas Instruments' TL780-05, a 1% "precision" regulator. It's debatable whether it would actually provide "better" regulation in your application, and even more debatable whether it'd have any meaningful (audible/measurable) effect on your DAC's output.

I mean, to put things in perspective, most reasonably common, reasonably affordable multimeters are probably accurate to 1% or less, so you're worrying about variances that are probably not reliably measurable. Considering what passes in the world for "12VDC", a few hundred millivolts from nominal on your DAC power supply is *more* than "good enough"...

[gurusan]

ok, gotcha.

But anyway.... I happened to have a few spare National Semiconductor LM1086-5 regulators around from a project a long time ago.

I popped one in to replace the old L7805 and now the DMM reads 5.01V constant. You are right, I can't detect any audible difference, but my obsessive mind is at ease now

[AZNracerx1989]

I used the opa sun hdam on this DAC and it sounds really good! But where do I ground it? AG or the other grounds?

[kirimaru]

I just recieved the dac,its sounds ok but it make hissy noisy when the sample rate is over 48khz.
I think i am missing something,can somebody enlightme ?
thanks.

[linuxworks]

I believe you have to change a few things (nothing big, though) to get 96k to work!

research it but it does not support 96k as shipped. look for that lampazilla (sp?) guy - his website had some dialog on what things to wire where to get 96k 'back' again.

[adamus]

edit - beaten to it

yes, you need to do a mod to get it working over 48khz. look on the diyaudio forum. Its somewhere in there (digital section)

[gurusan]

done this and confirmed as working. careful lifting the leg though. might be best to just cut the trace

diyAudio Forums - CS8416/CS4397 board at 96kHZ? - Page 1

Originally Posted by error401

I would normally expect a DAC using this IC/receiver combo to utilize the 96KHz pin on the CS8416 to select a high sample rate mode in the DAC when you apply such a signal. An obvious failing of the design. M4 is the CS4397 pin that puts it in high sample rate mode, you'll need to disconnect it from ground and apply an appropriate signal.

You will need to carefully lift the M4 pin (2) from the PCB (...), and bridge it to the CS8416 96KHz pin (16) with a wire. This pin is an output so shouldn't be connected to anything and you won't need to lift it.

[kirimaru]

Thanks to all of you guys,you all were very helpful.
the dac is working perfectly at 96khz.
thanks.

[linuxworks]

hey, leave us with a photo or something!



glad it worked out.

[kirimaru]

I am going to recap the dac, so i will post the pics tomorrow.

[fordgtlover]

Here's my recapped version


I've made the following changes:
R2 3K
C3 10uF 10V oscon
C8 .1uf Polypro
C9 .1uf Polypro
C10 .1uf Polypro
C11 .22uf MKT EPCOS
C12 .1uf Polypro
C13 .22uf MKT EPCOS
C16 100uF 16V os-con
C17 100uF 16V os-con
C18 100uF 16V os-con
C19 Rubycon MBZ 1500uF
C20 100uF 16V os-con
C21 470uF Panasonic FM
C22 22nF
C23 1nF
C25 10uF 10V oscon

R8, R9, R14, R17 30K
C32, C33, C34, C35 150pF

Opamp opa2107

Leo's bypass mod
C27,C28,C30,C31,C6,C54 Bypassed
L & R out C 2uF Obbligato PIO
L & R out R 51 Ohm Kiwame

[adamus]

I use the 2107, tried quite a few and it was the king.

[kirimaru]

Sorry for the delay,here is the photo.
[IMG] [/IMG]

[fordgtlover]

Originally Posted by adamus

I use the 2107, tried quite a few and it was the king.

I have got to admit that the 2107 was the first one I grabbed. I liked it so I haven't rolled any others , but I have made up for it by swapping out a stack of caps.