DAC AD1862: Almost THT, I2S input, NOS, R-2R

It is not finished yet, but I'm working on it
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Why bother with ad 1865 when you have the way better ad1862 with uf l pads already ?
Anyway, look at wjat did Miro on that board to add your 3 uf-l sockets in the same order than the fifopi to avoid the cables cross itselves. Keep the register and avoid the i2stoPcm board... Use short uf l cables...2" is fine if you find it.
 
Why bother with ad 1865 when you have the way better ad1862 with uf l pads already ?
Anyway, look at wjat did Miro on that board to add your 3 uf-l sockets in the same order than the fifopi to avoid the cables cross itselves. Keep the register and avoid the i2stoPcm board... Use short uf l cables...2" is fine if you find it.
Runs at 5v and has an internal i/v. that doesn't sound like a cool concept to you?
 
Why bother with ad 1865 when you have the way better ad1862 with uf l pads already ?
Anyway, look at wjat did Miro on that board to add your 3 uf-l sockets in the same order than the fifopi to avoid the cables cross itselves. Keep the register and avoid the i2stoPcm board... Use short uf l cables...2" is fine if you find it.
The attached picture was not too good. I used the RPi CAD model just for the pin reference.
In the reality, top of the Rpi would be the FiFoPi board, and my DAC connecting directly to the FiFoPi's isolated 40pin connector.
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I don't want to use u-fl connector and cables. This is the base of my concept.
And why want I use AD1865? Because I already have this DAC, and sounds very good with passive I/V and tube ouput stage. This is the current configuration:
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I never tried with the header, theorically it is the same than the uf-l or even better cause shorter. However I had always a doubt due to the material of the pins, plastic isolator, impedance respect...though few mm it should do not arm...but I don't know as I never tried the fifopi header, just its uf-l outputs.
Looks good, what tube do you use ? What reg for B+ please ?
I like the Jenzen and Jantzen DC caps... What are the main caps on the regs ? Looks like, Nichicon UKZ or Panasonic FM...even Black Gates Std ? But as I see another Nichicon I bet the black are KZ...

That is a really clean job you made...resistors also chosen with care. You will certainly surprised by the difference on the two digital front ends...
 
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That's pretty darned cool. I dig it.

Do any of you know what the op amp in the AD1865 is comparable to? I know the spec sheet suggests using an NE5532 as a low pass filter, maybe it integrates an NE5532 type circuit for
I never tried with the header, theorically it is the same than the uf-l or even better cause shorter. However I had always a doubt due to the material of the pins, plastic isolator, impedance respect...though few mm it should do not arm...but I don't know as I never tried the fifopi header, just its uf-l outputs.
Looks good, what tube do you use ? What reg for B+ please ?
I like the Jenzen and Jantzen DC caps... What are the main caps on the regs ? Looks like, Nichicon UKZ or Panasonic FM...even Black Gates Std ? But as I see another Nichicon I bet the black are KZ...

That is a really clean job you made...resistors also chosen with care. You will certainly surprised by the difference on the two digital front ends...
I'm using 6N23P-EV tubes. On the photo the output stage is an unbypassed SRPP, meantime I made another output stage, bypassed SRPP, and the Output capacitors are now V-cap ODAM.
Currently the B+ supply is a simple TL783 reg. something similar:
https://cdn.imagearchive.com/groupdiy/data/attachments/13/13618-09209bee75c0fa3174ef97d4b1fa75fa.jpgBut few month ago one of my fried recommended Ale Moglia's Mu-Follower panels (I built a phono stage with these Mu-Follower panels, and I have positive experience with it): https://www.bartola.co.uk/valves/2019/02/03/hybrid-mu-follower-aka-gyrator-rev08-pcb-update/
Main caps on the B+ supply are Nichicon KX 330uF. If you want to start now, go with the Mu-Follower panels. I also want to replace the old supply in the next few week.
 
Have you tried this board? do you feel the difference in sound quality? would you recommend it?
I'm thinking about buying Bluesound Node (nice OS, but bad power supply) or building something based on RPi + Volumio( paid subscription, strange UI (in my opinion), can reach better sound quality, than Bluesound Node).
Thanks!
I didn't tried it yet, I bought it a few days ago, I'm waiting for the post 🙂
I'm using Roon on my Raspberry Pi (USB port of the Raspberry conected to the JLSounds card), and I'm satisfied with the sound quality, but I hope with FiFoPi will sounds at least same quality, and I can use JLSounds card for my other project.
 
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Gaszto,
Similar here. I adviced this tube in this thread and uploaded Thorsten Loesch pdf paper on his i/v stage with the close ecc88.
Idem as you a friend advised me Moglia cathode gyrator as well...css sorta.
I am curently looking for a HV reg for the B÷ to avoid the expensive choke loaded reg.
I look at K&K but far from Europe..taxes and customs are b...h . I m looking for also a soft start for the B+ , delay can be made passive...see Loesch paper I linked in a post here.... I also hesitate to make a soft start for the heater while people say a IHT doesn't need it...but as I want to use SS rectification that has inrush current at start on....
I am very slow at building things these days...too many projects to finish.
Well done for your tube output 🙂
 
The pcb of the passive I/V AD1865 for RPi.
This version working with RPi, and there are 4pcs U.FL connector external PCM signal. Registers powered from the FiFoPi clean power, AD1865 digital part powered from separate connector.
If it looks ok, I'll populate Gerbers, and I'll create a another version U.FL connector for I2S signal instead of the 40 pin connector.
 

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