DAC 2496 (AK4393) DAC KIT With CS8416+AK4393+5532

[Black Stuart]

Erin,
I use both h/amp and speakers but my preference is to listen through speakers. A h/amp is the best way to evaluate any mods since there is no hiding place using a good, sensitive h/amp. What has surprised me is that the power version of the Bada h/amp conveys almost as much detail as the h/amp and that with only a change of the coupling caps - I ditch any Solens I find as well as Wimas, though I will give Darios Wimas a chance.

50AE - I was persuaded by my Dutch mate Harry to shell out(spend for non English speakers) for a pair of Dutch hand made silver foil 0.47uF caps - they were not cheap but worth every penny - I shall swap them into the Bada power amp.

For those using cap out with this DAC - ERSE caps, very cheap,very small and better anything other than the most expensive caps. They go deep and the top is as sweet as a nut. You have to buy a minimum of $25 (I think) seriously give these caps a try - a 3.3uF would be a good value to try.

Re. PSU caps - I was lucky enough to buy in lots of Philips LL caps and Rifas both of which are now NOS. Unfortunately I don't have any with enough poke to use with this DAC. The Philips are superb with just a hint of warmth and I can't understand the fanatical support for BGs especially the hugely expensive PSU caps and in a straight fight between the original Silmics (not Silmic11) and BGs, the Silmics bass is way better.

Erin - I once did'nt understand that neutral does'nt mean bland , quite the opposite. Neutral means more of the original signal gets through. So I don't want anything other than a neutral response. With a less than neutral sound timbre and colour is lost. Piano and electric guitar are excellant for showing what kind of sound a system produces, if the music is mellow then it should sound mellow and if an electric guitar is jangly and sharp then for me that means my system is reproducing what is on the vinyl or CD.

A suggestion for those who bought finished boards - instead of de-soldering components, think about cutting just the bodies of the Rs or caps (the components supplied are cheap enough to destroy), leaving the leads still soldered to the PCB - solder onto these and when you are satisfied with your choice of component then and only then de-solder the original legs and solder in the final component choice. Wait until you are happy with the whole sound and take the PCB out just the once.

My limited knowledge is about analogue circuits not digital so this DAC will be a learning curve for me and I hope that I shall approach this with an open mind.

Stuart

[PreSapian]

a guy who i sold this dac to just informed me that the board still makes sound when he takes out the op-amp, and that the tranformer overheats when doing so.

what is going on here?!

it also makes sound when he plugs in the op-amp backwards.

[hotiron]

Yes, there is a resistor in the feedback loop connected to both DAC and output, thats why you get sound with no Opamp. The transformer overheats when the opamp is connected backwards because the opamp is now fried and shorting the power supply.

[haik]

I have a specific question.

The DAC kit goes into an "undefined state", when no S/P-DIF signal is present. It gives a +/- 250 Hz, 26 mV output. (when the SP/DIF is available, it goes "silent" and only 0,1 mV on the output is present).

The "auto detect" function in the CS8416 which should give a high or low on pin 15 is not working properly. Even with no input, it shows a low output and the AK4393 (pin 8) is also low. By datasheet is means:

Soft Mute Pin in parallel mode
When this pin goes "H", soft mute cycle is initiated.
When returning “L”, the output mute releases.

When connecting a CD-player (Marantz CD4000) and switching it on, the output changes, and the output on the opamp goes to 0,1 mV. (when no CD is inserted).


Anyone knows why the does not sense "audio or no-audio"? Normally the LED should be illuminated when no audio is connected, by the led is dark.

[bcmbob]

Very interesting, as just this morning I had a situation where both amps and the DAC were powered up before I turned the computer on. I got a low level yet smooth hiss with the error light on. As soon as Windows activated the S/Pdif driver the error light went out, the "96 present" led activated and the hiss disappeared. I didn't see it as a big problem and suspect that protection circuit/function is not fully implemented in this design.

I'll also be interested in any further details and or mods. With the MyRef amps I'm using, the DAC MUST be on (signal or not) first to avoid some really ugly and possibly speaker damaging noise.

[ch33ta]

CS8416 is the source of your problems - the hiss you mention...
When it loses SPDIF signal, PLL loses lock and VCO frequency drops to ~750 kHz,
and you get the hiss on your DAC output.

However there is a simple solution to this problem - just connect a 11.2896 MHz oscillator
to the OMCK pin on the CS8416 - tried it and it works great.

For a more detailed explanation read page 28 in the CS8416 datasheet.

[bcmbob]

Thanks, I'll give it a try.

[ch33ta]

BTW. just to mention, on these ebay DAC kits, the OMCK pin is soldered to ground.
So you should desolder the pin, and pull it up, than solder a thin piece of wire to it and connect to an oscillator...
Not an easy task, you have to be very careful not the break the pins of the CS8416, but I managed to do it on two DAC boards so far, so it's not impossible...

[haik]

Hello ch33ta,

Do you have a schematic for the 11.2896 MHz oscillator? I would like to build one.

Haik

[qusp]

Originally Posted by PreSapian

a guy who i sold this dac to just informed me that the board still makes sound when he takes out the op-amp, and that the tranformer overheats when doing so.

what is going on here?!

it also makes sound when he plugs in the op-amp backwards.

erm, what possesses a sane human being to deliberately verify if the opamp works backwards