DIY DAC with premade PCBs, some questions

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For good, problem free USB, try the latest version of I2SoverUSB with two isolated linear power supplies. Put shielding around the USB board because its a source of radiated EMI/RFI that can get into subsequent dac circuitry. Then reclock again, try a FIFO buffer, or whatever else you want to do, then put another, different shield around that. Then put the dac chip, or other dac D/A converter itself in its own shielded environment too. BTW, that's what stuff like Station_Pi and Shield_Pi are trying to do; however IMHO that approach doesn't work quite as well as it could if it weren't limited to RPi stack form.

IOW if you want an exceptional dac, IME you have to go to exceptional lengths to make it as good as you can. Does all that attention to detail make an audible difference? IME it does, at least if the rest of the system is good enough to accurately reproduce what's coming out of the dac.
 
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BTW, that's what stuff like Station_Pi and Shield_Pi are trying to do; however IMHO that approach doesn't work quite as well as it could if it weren't limited to RPi stack form.
true, i probably will play around with shielding too... thanks for the tips

and from a video i got this idea: clocks on a seperated board which is suspended... i have to see how my setup ends up to maybe implement that too

If you are that bothered use a USB isolator.
i wish it would be that easy, i already have a Topping HS01 here, usb cables and tweaks (ifi isilencer for example) still matter, so only usb isolator doesnt change much
thats why i create this ground loop eliminator pcb, just to see if further improvements can be gained
 
Regarding HS01, I tried it and found it made USB noise worse. It seems that it has some kind of internal SMPS that is powered from the PC side of the USB bus. The SMPS will power the DAC side of HS01 if no external power supply is used.

My comments on it in another thread: https://www.diyaudio.com/community/threads/problematic-usb-isolator-unit.399247/post-7356655
hmm for me it never made it worse, but also not much better... ifi isilencer is more of a audible change

tho there are other flaws with it, not properly reconnecting on its own for example
 
It seems to me that everything is unnecessarily complicated, so that in the end you won't even get anything done.

The latest I2SoverUSB board, Miro AD1862 NOS DAC (or AD1865 or PCM1702) and power supplies for it all.

NOS DAC is not very sensitive to jitter, it is quite simple, and sounds great with some discrete OPAs, incomparably better than that Chinese confection (Topping and the like).

You also have DDDAC, where you pay more, but you just stack completed and tested modules.
 
You can also pay more and connect boards from TheWellAudio. I use some of their stuff in my experimental dac, and it sounds very good. Of course it looks like a lab experiment too. Not done experimenting yet, is why.

Attached below left is what it looked like at one point, fairly neat. Now it looks a lot messier but sounds considerably better.

The black rectangular object seen in the lower right between the USB board and PCM2DSD converter is a metal plate covered in gaffer tape so it won't short out anything. It shields the board on the left, a FIFO buffer and dac controller board. There are steel walls between that stuff and the dac itself along with its reference voltage regulators and discrete output stage shown in the upper part of the pic.
 

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well NOS dacs are different kind of beast, im just not happy about that they cant utilize DSD

if i wanna go with the DSD route i either have 2-3 DSD dacs or delta-sigma to choose from as it seems
ESS im kinda tired of (3 dacs with ESS so far), i definitely wanna try AKM... they also have better options for dsd playback as it seems

i started looking in doing two own pcbs with ak4493 and ak4137, it seems doable but i would need to learn alot about pcb design, im just worried about wasting my time on "older" chips, tho ak4493 also seems easier to implement than the newer models

i also was thinking about buying some AKM dac and start tuning it myself...
Geshelli J2 is kinda perfect because it takes amanero modules... i could still play around ak4137 or pcm2dsd board

geshelli would be also one of the few options with ak4499... and even changeable opamps... but comes at around 800 euro i think if i import it




maybe i should just start with a DIY protodac pcb.... just to see what NOS with PCM sounds like compared to my current setup, maybe its better than DSD + delta-sigma chips....
 
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DSD is made from PCM format, why should it be better? It's completely irrelevant, believe me. Your best bet would be to get a good DIY NOS DAC from someone to try out. So I started with the DDDAC, and then I built more of those NOS DACs and it all sounds better to me than the Delta-Sigma in the same price category. Even these chips I use (PCM63/PCM1702/AD1862/AD1865) sound better in NOS mode, and do higher sampling rates. Those Delta-Sigma DACs are killed purely by oversampling and digital + analog filters. Oversampling leads to jitter sensitivity and the need to at least digitally filter the noise. Most often the result is a tiring & dull sound.

My recommendation is the AD1862, available from Digikey or ebay. PCM63 might be the best, but it's hard to get, they usually ask a lot of money for used chips. It is a big risk because it is sensitive to soldering & desoldering. The only thing I haven't tried yet is the TDA1541A. And I will probably try that soon, I need to put together an AYAII kit by Pedja Rogic for my friend.
 
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DSD is made from PCM format, why should it be better?
well because the conversion from pcm or dsd to analog is different, i think thats mostly the reason

Those Delta-Sigma DACs are killed purely by oversampling and digital + analog filters
deltasigma chips handle DSD differently to PCM, did you compare DSD on delta sigma to NOS?

Oversampling leads to jitter sensitivity and the need to at least digitally filter the noise. Most often the result is a tiring dull sound.
the key is to use good resampling algorithms, there are large differences between them, also IME oversampling with good algorithms leads to less jittery sound, smoother, more analog yet again, crap algorithms like the windows once... well sound crap

if im not currently using hqplayer my setup includes pipewire which upsamples to 176,4khz with the resampling settings maxed out, much better than windows imo
 
I haven't dabbled much with DSD, I have a huge archive of PCM music and NOS DACs. We compared on Topping D50S and SMSL SU9 DACs PCM vs DSD. It all sounds the same to me, not worth bothering with. And the files are much larger and just take up disk space. A lot of people here listen mostly to Deezer and Tidal, which is PCM FLAC format. I don't see that DSD matters much. It can also be converted back to PCM if needed.
 
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I was mainly attracted by the sound of the old R2R chips in NOS mode, although some are not R2R (TDA1541A) and most of those called R2R first 6 bits actually process in Thermometer code. I haven't tried these discrete R2Rs that are available, because I doubt the possibility of making a 24bit DAC with resistors.
 
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hmm ... what about these? it might be worth testing NOS before i go all into DSD...

https://de.aliexpress.com/item/1005004602930094.html

https://de.aliexpress.com/item/1005004000761155.html

both could be equipped with high quality parts

or do you know a better pcm1794 or similar variant pcb?
Im also curious about these dacs, please buy one and test :D
A Ukrainian speaker maker uses this same dac, made by LHY Audio in his setup, you can check out his set up on his YouTube channel, which even via YouTube sounds great!
BTW - in the comments he provides a drive link to his parts list and designs, well worth checking out, his electronics are all together under €1k! o_OBest of luck