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

[juancho]

I agree on the power supply but IMO the DAC sounds many times better with a reclocker (Kali in my case) and a valve output stage. I use the Broskie unbalanced with separate custom power supplies for each channel. Sublime!

 

[smooth dancer]

Acoustic treatment in the ceiling, and absorbent’s in first reflection spot.

 

[smooth dancer]

Ok juancho, maybe kali is next step, but time will tell. I am so pleased with the sound as it is now.

 

[mbrennwa]

Sorry if I ask again. Have you experimented with other solutions or you are just happy with the stock?

I have installed an RC filter with a HUGE C in between the stock PSU and the DDDAC. I could not hear a difference.

 

[mbrennwa]

Ok juancho, maybe kali is next step, but time will tell. I am so pleased with the sound as it is now.

Good luck with the Kali. It worked fine in one of my DDDACs, so I got another one for my second DDDAC. Didn't work well. I swapped the Kalis between the two DACs and found the newer Kali is the problem. I suspect Allo changed something with the Kali, but they couldn't really help to solve the issue. I went with a HifiBerry instead, and the sound quality is about the same as with the "good" Kali.

 

[juancho]

I've implemented two new Kali's n recent weeks and none of those or older ones have presented any problems.

But the valve output stage would be my first recommendation for the biggest increase in SQ compared to capacitors, Sowters, or Cinemags

 

[mbrennwa]

I've implemented two new Kali's n recent weeks and none of those or older ones have presented any problems.

That's good to hear. Did you do the WaveIO -> Kali -> DDDAC thing? Or some other setup?

But the valve output stage would be my first recommendation for the biggest increase in SQ compared to capacitors, Sowters, or Cinemags

What circuit did you use? Is it DC coupled to the POS and NEG outputs of the DAC chips?

 

[juancho]

I did the Wave, Kali blue board set up.

 

[juancho]

'What circuit did you use? Is it DC coupled to the POS and NEG outputs of the DAC chips?' as above I used the Broskie unbalancer with custom separate channel power supplies using high voltage regulators. It is cap coupled to pos and neg DAC outputs

 

[edwtsui]

Hi,

Just want to clarify one thing. For power supply PCB, C1/C3 were marked as 4.700uF but those two are the largest among all cap. Should they be 4700uF instead of 4.700??

 

[mbrennwa]

Hi,

Just want to clarify one thing. For power supply PCB, C1/C3 were marked as 4.700uF but those two are the largest among all cap. Should they be 4700uF instead of 4.700??

The dot is confusing, if not wrong. 4700 μF is right.

 

[edwtsui]

The dot is confusing, if not wrong. 4700 μF is right.

Thanks. Supposed they are reservoir caps and shouldn't be that small.

 

[karahana]

I tried different configurations with my dacs and what I did come to
1 Battery is very clear, it improves basically everything but lacks the dynamics (no go for me)
2 ReClock board is very dependent on the power, different power gives different lets say signature and clarity
3 Tube output gives in comparison to duelunds only analog sounding. Since I don’t have very good tubes (6H6P) I lose some clarity and presence. I presume with good DHT (like 101D) it will add some magic. It would be an interesting comparison between sowters and tube.
4 Again confirm the point of view that the sound is a modulated electric signal. Without good power, there will not be good sound.
If I need to rate the impact
1. Power
2. Reclock (it does make difference)
3. Tube output (maybe it as big as reclock with good tubes)

So I think that noise numbers are not as important (after a certain level) as the load.
Still reading the thread for the power options.
As always will appreciate any enlightenment.

Has someone used Sjostrom psu (SSR04)? It has low output impedance and 0.9 uV noise

 

[karahana]

Smooth dancer thanks for the pic! It is great psu though costly. I know the magic those jbls can give))

 

[karahana]

Juancho! May i ask you to send some pics of your dac? Did I understand correctly that you have compared sowters cinemags and capasitors with valve output and preferred valves? What was the difference that you heard?

 

[juancho]

I agree but tube output with JJ802s beats reclocking

 

[juancho]

Juancho! May i ask you to send some pics of your dac? Did I understand correctly that you have compared sowters cinemags and capasitors with valve output and preferred valves? What was the difference that you heard?

Correct. Valve output is an easy win over Sowters for me. The music flows better, sounds more organic and has better drive and dynamics. Valve output also works really well with two boards. I'll do some pictures in the next days

 

[karahana]

Thank you! As i was quite impressed that sowters were considered better choice than tubes, i thought it should at least as good, may be the dac itself has organic analog sound. so.. Volume control is a nice addition though.

 

[mbrennwa]

Thank you! As i was quite impressed that sowters were considered better choice than tubes, i thought it should at least as good, may be the dac itself has organic analog sound. so.. Volume control is a nice addition though.

How many DAC boards do you have in your DDDAC? I'd guess that you need at least 4 boards to get sufficient drive capacity (low ouput impedance) for the next stage. Also, a transformer volume control (TVC) helps a lot to improve output impedance (as long as it is not set to max. volume).

 

[edwtsui]

Hi there,

By comparing the schematics between 4.2 & 5.1, I can see there are many changes on DAC board.

1. What is the purpose of adding a UA7810 between LF33 and a shunt regulator? Can I regulate the voltage directly from 12V to 8V without UA7810?

2. Why the decoupling caps changed from 47u+100n to 10u+100n in version 5.1?

3. If I don't use Tent lab shunt, any alternatives?