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

yes very lately after we talk. I made first the error because the marking with the two first bjt despite you advertised me, lthen eft it few months after some problems, then completed it later. Sounds more than good, different from my reference but hard to compare as my ref diy dac has a complex digital front end and clock and had 3 years of work, on passive parts and multiples supplies ! Stock, although yours sounded better than my stock ref tda1541A S1. I see you also use R-core traffos as I did and it is one of the little trick that sounds good with this dac chip... I surmise yours onthe photo are old Selectronic with the screen wirered to the main ?

Thanks again for the two boards you sent me back then. If you want to try Miro's for the curiosity I can send you some boards I have left.

here people

Right. I don't mean to hijack this thread in anyway, I'm just curious.

Did I send you the previous version with the non-smd output stage? I think I remember that there was an error there on the boards, which marked the transistors in the wrong direction.

I think maybe the AD1862 is inherently better than the TDA1541, so it's an unfair comparison. It would be interesting to test the AD1862 with a different discreet I/V stage.

I would love to test miro's boards for comparison. If you have a couple boards left you can pm me about it.

I don't remeber how I wired the trafos. I am guessing that I left the screens floating. My memory isn't very good these days.
 
Hmm, maybe trying out the trimming stage should be next experiments... thanks for the information!
I think I was a little inaccurate in my description. You can either use a scope and feed your dac with a -60dB sine signal and trim until you see the least amount of noise on your output. Or you canhook up your speakers and feed your dac with a very low input digital signal, while putting the volume of your amp to max, and you'll hear audible noise. And then you just trim until the noise goes away. I have done this many times. I have 110dB sensitive speakers, and the noise is really audible. I think maybe diyhifi is down now, but that's where I learnt this back in the day, and I have repeated this procedure several times.
 
@Painkiller - any chance you would have a written procedure on how to do it?

Displaying my ignorance here, but how do you make the -60db file for the source? Exactly what do you look for on the scope? For example if the -60db is a 1khz sine, do you adjust until that 1khz is gone or is it something else?

Its a question that has come up a few times, and in truth, I've always had more basic things to fix first!
 
RE setting the trimmers for minimum distortion.
I use a S/PDIF Digital Audio Signal Generator.
It was a Siliconchip project from quite a few years ago.
https://core-electronics.com.au/s-pdif-digital-audio-signal-generator-kit.htmlI set it for 1k hz and adjust the level to -60dB.
Then look at the output with a scope.
The sign wave has a sort of cross over distortion & as you adjust the the trimmer you can zero it out
until you have a clean looking sign wave.
I will post some before and after scope shots tomorrow.
 
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Finally I could finish the DAC.
I appreciate to Miro,Meanie,Garcia and ppl here.
I use to use Topping D70 using XLR connect.
Now I concentrate on music and more enjoy the siund more than before.
 

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Hi, I decided to give this DAC a go, got the DAC chips from Paddy and ordered the parts up, however I'm unable to upload the Gerbers for the I2S/USB board not flipped from post 2546 to JLCPCB, my go to PCB fab.
PSU1 uploads fine as does the board with the shift registers but not the one that I want,

Anyone else encountered this?

Andy
 
Hi, I decided to give this DAC a go, got the DAC chips from Paddy and ordered the parts up, however I'm unable to upload the Gerbers for the I2S/USB board not flipped from post 2546 to JLCPCB, my go to PCB fab.
PSU1 uploads fine as does the board with the shift registers but not the one that I want,

Anyone else encountered this?

Andy
I had the same issue, seemed like the render function on JLCPCB did not work. Had to manually input the size and skip the render and it worked.