Hifimediy direct out cs4398 DAC

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Hifimediy has started devloping a DAC with cs4398 chip and no output stage or LPF. Instead of adding cost with an output stage that some people will bypass to build their own or just go cap/trafo out, we will focus on only digital part and cutting cost by leaving out unecesary parts.

The background of this is several reports of Vout dacs sounding better direct out (with or without a cap or with trafo), or a simple lampizator style tube output stage.
I tried this last year and exerienced an increase in sound quality almost as big as when I switched from tube amps to tk2050 amp.

link to my post about direct out DAC:
http://www.diyaudio.com/forums/class-d/164274-new-tk2050-board-39.html#post2235475

Have been wanting to make a dac for this for a while, and we are now getting closer!
Yubing came up with this design as a start.
WM8805 receiver cs4398 DAC
no LPF or output stage
coax and optical input
It should work even without a output cap, but that might be depending on the amp.

What do you think?

Steinar
 

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Hi. Nice project for advanced diyers. I think of the people like me who use a laptop as source with no spdif output. Any chance to consider a top notch usb 96/24 input as well, based on Tenor TE7022L or similar ? this would certainly increase price quite a bit.

@scott : second the need for excellent clock.
wolfson WM8805 receiver has actually even better specs than DIR9001 :)
 
As a general diy kit, it would be nice to expose the s/w interface pins for both chips. Then some simple jumper/switch configuration can allow h/w or s/w mode.

A couple of cost effective improvements:
- A clock with its own low noise regulator feeding the WM8805 (rather than a crystal)
- A low noise regulator for the analog section of the DAC chip
 
Hi all, and thanks for the input on this.

Yes, I think we definately should include a good quality clock.
We will also consider upsampling chip (in hardware mode)
I think we should make room on board for output caps (or trafos). we could supply it with output caps which would be very simple to remove if needed and add minimal cost, at the benefit of being plug and play ready.
USB input is also an option, TE7022L is an interesting option, but would add costs.

It might be an idea to make different versions of this DAC, using the same PCB but leaving out parts for different versions: no usb, upsampling versions, could be bypassed with jumpers.
 
One thing I think worthwhile adding is a digital volume control. This will allow direct connection from dac to tripath direct. The chip already comes with that built in. So might as well use it. I tried something like that once, I was using the inverting stage of the tripath chip as an IV converter for my Tda1541. Sounded pretty good but implementing volume control was a huge pain...

Oon
 
update

hi guys.
I finished the first version of PCB drawing these days, and here it is.
So, the CS8421 will be used as sample rate converter and it can be bypass by resistors. also, a TE7022 will be used or not installation. The DAC module support different voltage output DAC chips and CS4398 will be the our choice at first. The board need 2x AC 9V power supply for digital and analog part for better performance, or single 9V supply for them both.
 

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Looking good. I have an Audio-gd DAC that swaps out a DIR9001 receiver or a Wolfson. The DIR9001 is clearly better in that DAC. Have you all considered using it? This looks to be a very fun project. How many amps will the 9V power supplies need? Any plans for some nice power supply boards to go along with the DAC? I have been wanting toi build a supper integrated and I see the HiFiMe products lending themselves very well to that project. :D
 
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