Hi end DAC kit ebay

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Did anybody bought this one and had a listen? I'm really interested in the sound of this unit in STOCK FORM! Because, one can mod this dac, but this will lead to a never ending story. In the end one has to replace nearly ALL the parts on the pcb, and this way it doesn't make any sense to me to buy a completely assembled and ready-to-run dac module.

So, how do these modules sound without any mods?

Thanks a lot!

Martin

I just ordered one 2.0B OS/NOS, one input module (want to try the USB) and one tube output module. I'll let everyone know how they sound. I can give you the set-up right now:

Source will be uncompressed audio files ripped off CD's played from the computer via USB.

The Tube output module will drive two Quad II with NOS GEC tubes and fresh capacitors.

Speakers are (1) Yamaha NS1000M and (2) Lowther DX2 with PM6 cones (the later in "Mini monitor" cabinets)

/p
 
Tube output

HI FLANCFUSTER,
did you know what is Zout of your R.H.Tube Module DIY Kit for DAC.
I am Very intersted in sonic feedback of it despit your "artifact" problems.
Thanks in advance
Yoran

Hi Yoran, I've modified tube output from raindrop_hui. Changed tubes with 6H1P(miniature, from Russia). I like it!!!
The artifacts are gone. One voltage regulator was not working properly. Raindrop send me another one to replace it. Now everything is working fine.
Personally, I prefer 6H1P over the Raytheon 5744.
Sorin.
 
Stuff arrived from Raindrop!

OK, folks, here we go!

The package arrived two days ago, in spte of constant ash-stops in air traffic. Inside were 3 pcb's with all components mounted and two tarnsformers.

I have tested the input module and the DAC itself. The tube output stage had too much gain so I will have to measure and adjust. Besides, I don't have the schematics yet, so I'll wait for them to arrive before I try it out.

Anyway, the sound is absolutely fantastic. Well balanced, solid bass and crisp high ends. Voices sound great with this setup. I have only the NS1000M's hooked up at the moment, and I have never heard them sound as good as now.

The input module's USB chip (CM102S) took some thinking, googling and tricks to get to operate properly. Apparently, the driver that is included in Windows doesn't support a volume control for the main volume - this was a total drag. A numer of hours later I find myself with a driver! Yeah! If someone has simular problems, I'll be glad to post it. It works under Windows 7 Media Center with all bells and whistles.

I have hooked up the Airport Express via TOSLINK and the media center computer via USB. DAC output is straight to the inputs of two Quad II mono blocks with fresh NOS tubes and all passive components exchanged for new ones. Quads drive one NS1000M each.

I am very satisfied so far and look forward towards getting the tube output stage in the loop.

/p
 
Hi Yoran, I've modified tube output from raindrop_hui. Changed tubes with 6H1P(miniature, from Russia). I like it!!!
The artifacts are gone. One voltage regulator was not working properly. Raindrop send me another one to replace it. Now everything is working fine.
Personally, I prefer 6H1P over the Raytheon 5744.
Sorin.

Could you please make some short comments on what is that what you like more with 6H1P. And perhaps elaborate on some characteristic sound differences?
 
More info...

Tried to switch it to NOS mode. This is accomplished by pulling the 7220 out and closing four DIP switches mounted underneath it. In NOS mode the signal was badly distorted, and from other info on this forum I have concluded that it is because the I2S lines are neither loaded nor attenuated. I have ordered a small inductance and a DIL socket in able to build an I2S attenuator suggested here.

More to come...
 
Could you please make some short comments on what is that what you like more with 6H1P. And perhaps elaborate on some characteristic sound differences?

After tube output modifications, the highs are better, bass is deeper and some HF interferences are gone (with Raytheon I could hear interferences probably from other devices nearby and I had to create a shield for them). For testing purpose I've build a small and simple I/V stage with LM4562 and compare them. I have to say that LM is good, but tubes have something special to my ears. Amplified with a SE 6C33C (Borbely schematic) is definitely a beautiful match for me.
To answer the question regarding 2XTDA vs. 4XTDA, personally I haven't heard any improvements with 4XTDA.
I recommend TDA1541A with tube output(lampizator or whatever you like) and SE amplifier.

Regards,
Sorin
PS. Tubes are these ones(I'm not very good with Cyrillic letters, it may be 6H1P or 6J1P :
tube.jpg
 
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After tube output modifications, the highs are better, bass is deeper and some HF interferences are gone (with Raytheon I could hear interferences probably from other devices nearby and I had to create a shield for them). For testing purpose I've build a small and simple I/V stage with LM4562 and compare them. I have to say that LM is good, but tubes have something special to my ears. Amplified with a SE 6C33C (Borbely schematic) is definitely a beautiful match for me.
To answer the question regarding 2XTDA vs. 4XTDA, personally I haven't heard any improvements with 4XTDA.
I recommend TDA1541A with tube output(lampizator or whatever you like) and SE amplifier.

Regards,
Sorin
PS. Tubes are these ones(I'm not very good with Cyrillic letters, it may be 6H1P or 6J1P :
View attachment 169032

Thanks for the comments and thanks for the photo. From there I can see it is neither 6H1P or 6J1P.
Letter: Ж does not have real equivalent. We use Ž in latin lettering eq.
What I have understood it is not sub-miniature tube but miniature: 6Z1P-EV/6Sh1P-EW
Which means totally different tube!?
 
Thanks for the comments and thanks for the photo. From there I can see it is neither 6H1P or 6J1P.
Letter: Ж does not have real equivalent. We use Ž in latin lettering eq.
What I have understood it is not sub-miniature tube but miniature: 6Z1P-EV/6Sh1P-EW
Which means totally different tube!?

Hi Bassivus,
For your info I've attached data-sheet of the tube I'm using.

Regards,
Sorin
6j1p.GIF
 
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