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-   -   Experience with this DIY DAC ? (http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac.html)

ah-luo-ko-ko 5th February 2009 03:03 AM

Experience with this DIY DAC ?
 
2 Attachment(s)
Got this DAC from ebay.

No sound when using quad speed setting!

Need help.

How do I source a192K digital stream ?

hafp 5th February 2009 03:39 PM

If that DAC uses the CS4397 and CS8416 chips, you need to lift pin 2 of the CS8416 chip to ground and run a wire to pin 16 of the CS8416 chip.
There is much information about this DAC chip on message boards.
It will operate at 96kHz, but do not know if it is capable of 192k operation.
Good luck

ah-luo-ko-ko 20th February 2009 04:04 PM

Tks Hafp;

This DAC is based on CS4398 and CS8416. The CS4398 sampling rate is controlled by 4 dip switch to (manually) set M0, M1, M2 and M3 to ether HI or LO for sampling at 41K with de-emphasis off, 41K with de-emphasis on, 96K and 192K. It works with all setting except setting the control to 192K. When setting to 192K sampling, there is only hiss..

Wonder if anyone has experience with this DAC or is able to explain how to get the 192K sampling to work

johnm 21st February 2009 07:43 PM

Ahhhh the secret is out - this little DAC is fantastic...

I have this same DAC and am stunned at the sound quality for such a low price, especially with 16-bit lossless files. Unfortunately I am not able to try it at 192kHz setting as I don't have a source that runs this high alas.

Try replacing the op-amps for LM4562s - nice change ;)

For another tweak:

http://www.lampizator.eu/lampizator/...lampucera.html

Have you tired e-mailing the Ebay seller about the 192kHz setting? If it doesn't work then it's misleading information as it's sold as a 24/192 DAC!!!

cheers,

- John

ah-luo-ko-ko 22nd February 2009 06:49 PM

Hi John;

I did email the seller. However, since this seller is in China/Hong Kong, I ran into comms problem with him.After a number of email exchanges, he insisted that the 192 sampling work.

I came across another forum (audio-karma) where another fellow is encountering identical problem with the unit.

I did some research and it appears that in order for the 192K sampling to work, the input to the DAC has to be at some higher rate than the norm 44.1/44K. There is mentioning that source to the DAC has to be something like DVD-A output. What I do not understand is that DVD-A is an encoded format and it will be required to decode the DVD-A data stream to PCM to feed into the DAC for it tow work. Do you know if that is the case ? If so, when DVD-A is decoded to PCM, what sampling rate the PCM signal is at ?

johnm 22nd February 2009 07:14 PM

I'm no expert but don't you need a device capable of outputting a 192kHz digital signal into the DAC? (NOT 44.1....) ??

Kevin Wood 23rd February 2009 02:21 PM

I think John has hit the nail on the head. The CS4398 can operate in 3 modes - single, double and quad, as mentioned. These modes control the oversampling function built into the device. If the appropriate mode is selected the CS4398 will oversample accordingly for the best performance. 128x in single speed, 64x in double speed and 32x in quad speed.

Single speed works with sample rates up to 50KHz
Double speed works from 50KHz up to 100KHz
Quad speed works from 100KHz up to 200KHz

So, for 44.1K input (which I assume is what you have?) the best mode is single speed because the DAC will internally oversample to the maximum extent possible. It appears that you have got it working in double speed at 44.1KHz but this is below the rated minimum for this mode. It's actually only if your source has greater than a 50KHz sample rate that you have to switch it into double or quad modes.

Now, if you have a 96KHz source you would need to manually switch into double speed mode. Automatic switching can be achieved by making a connection with pin 16 of the CS8416, as the 8416 detects incoming sample rates above 96KHz.

I agree that this is a great DAC. Have had mine up and running for a couple of weeks, not tweeked as yet, and am vvery pleased with it. Will have to try the LM4562 though. :cool:

Kevin

Puffin 23rd February 2009 03:54 PM

I am a bit confused. I would have thought that you would need an up-sampler. Does this dac up-sample?

johnm 23rd February 2009 05:07 PM

Glad to hear you like the sound of this DAC too Kevin. I have to say, with the LM op-amps and a few days running in and a hefty torroidal transformer supplying the power it bested my Audiosector DAC in a number of areas which I found startling. It doesn't have the rolled off treble of NOS designs either, and all the problems that go along with it.

This thing seems like a gem in terms of modding too. I intend to perform the mods I detailed in the earlier post sometime soon. Should sound even better just bypassing the second op-amp, and all the caps. I have the feeling it will be a giant beater of a DAC after these mods.

Add this to a Shigaclone and you have a top flight CD playback system for under 100 - stunning! Using mine with a PC and Foobar2000 and my 16-bit files have never sounded better :cool: Going to build a chassis for it next, but will keep it simple and probably just use a wooden chopping board. For some reason digital sounds better to me without a metal case!

- John

johnm 23rd February 2009 05:48 PM

Hi Puffin: Yep I think it upsamples by design. I'd have to check the data-sheet to be sure though...


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