A NOS 192/24 DAC with the PCM1794 (and WaveIO USB input)

Brilliant :happy2:

Have to concur!
Works great with piCorePlayer. Choose the first I2S dac in the list and you're off!
Also tried Volumio, but as I go direct from the dac to my active speakers I need software volume control. Volumio's software volume control barely works. Good thing I had turned it all the way down before turning the speakers on 🙂.

So, am now running with Doede's 5V into the rpi, hooked via P5 header to the DDDAC.

Comparing it now to my SBT + booster, at first glance it does well....

btw, James, casing turned out nice!
 
Hej stijn001
why shall i not use a cap in the negative line ??..i use the balanced wiring ,where i use positive and negative and common......

Bjarne, I ran with the same wiring like you discribe with a cap on the pos only for a couple of weeks. But I'm running capsless now with no Vdc to speak of. I've made sure my Ra/Rb's were very well matched. in my setup Vdc is not an issue. Doede's idea about the adjustment with a pot should solve any Vdc issues.

I've still not decided if I'll stay cap'less or not. Cap'less is more detailed but thinner. I quite like the sound signature my Auricap caps were giving me, a bit fuller and more bottom end at the expense of detail.

If you put caps on the negative, which orientation are you going to use, reverse, exciting!? 😉
 
After Doedes tip...i have no dc from dac (0,7mv) no click in my volume
i am not sure if i will say the sound is thinner ,than with my aleph pre..the aleph have caps in input
maybe it is my Groundsound digifilter that make a difference..my amp comes after this filter
i will play some more days to find out ,,what i prefer ,,for now i will say the sound direct to volume, (fully balanced) is the best
best Bjarne
 
For those interested. I’ve been playing with an attenuator/potentiometer. Initially I wired it up in a conventional way (gnd/in/out). However I’ve now tested various values of a shunted attenuator. First of all the shunt attenuator sounds much better with a good quality shunt resistor, but also the DDDAC seems to be able to power drive it well which is the main thing, as not all sources do. A 10K shunt with a potentiometer of 100K to ground is working very well for me.
 
Interesting, any pics or schematic?
What potentiometer are you using? Did you contemplate a stepped ladder /attenuator?

By special request 🙂

Using the Alps is just for POC purposes, but sounds better then expected. Not adjusting volume in software is the big benefit for the setup I was running.

Obviously the qaulity of the Shunt resistor is critical in this senario. (I chose a Caddock)

btw, this obviously also mitigates the need for a bleeder resistor as well.


An externally hosted image should be here but it was not working when we last tested it.
 
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10k shunt with a 100k pot is a strange choice of values for shunt pot. I can see the DDDac would like the loo wish load but the range / function of the pot must be a little strange surely?
To keep a similar "feel" to the volume control law you normally choose a series resistor approx 90% the value of the pot track, so 91k with a 100k pot, 47k with a 50k pot, or 18k with a 20k pot.
 
10k shunt with a 100k pot is a strange choice of values for shunt pot.....

This combinations of values (+/- 1/10, shunt/pot) I've seen being used in different places, so they don't seem to be that strange. However I did play this by ear, through trail and error partly due to my lack of knowledge to calculate values properly. I tried 10K, 50K & 100K pots with a 10K shunt and the 100k seemed to me to be the best fit for my particulair DAC/AMP combination.

If I have the parts I'll give your suggestions a try.

What do you mean by "To keep a similar "feel" to the volume control law"?
 
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The shunt/pot values depend on the position you need your pot to be for your audio set (amplifier gain) and preferred loudness. You need to take care that the sum of pot+shunt is not to low, because this will draw to much current from the dac outputs. That maybe the reason that Stijn ended up at 100k.

You need to be aware that when using a shunt volume control the value load impedance changes at rotation and htis can influence the sound.
 
SPDIF pops between tracks

So, here I am, happy owner of a 2 deck DDDAC 1794S.

Building was easy, but now I have a minor problem.
When I skip a track, using SPDIF, I hear some pops / statics.
When I use the USB it's perfect.
It happens with all kind of SPDIF sources.

Is this normal behaviour, or can I do something about it (apart from using USB 😉 )

Thanks,
Jeroen.