why would you use 4 dac's stacked when the signal is stereo? I do have a lot of reading to but I would like to have some idea as of what is going on... I dream of building a DAC fo my self ...hahaha thank you for your time
regards angelo
regards angelo
I've you read this?
DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit
As a bonus, stacking the dac boards decreases the output impedance.
(The i/v resistors are 1/2 with 2 dacs, 1/4 with 4...)
DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit
As a bonus, stacking the dac boards decreases the output impedance.
(The i/v resistors are 1/2 with 2 dacs, 1/4 with 4...)
thank you much! apparently I have a lot to learn before I do anything, You don;t mind me asking sometimes, do you?
I swapped out the 3.3v reg for a Dexos Class d reg I had knocking around and the crackle has gone and the sound is improved. So the reg clearly corrects the crackle and it seems the opto coupling and data justification benefit from the 'super reg'
thank you my friend! should I start and read thru the entire stack of pages here or, you could direct me to the highlights perhaps?
we have a NOS DAC, which is a single channel, from what I understand...
and one of the main dealing issues in here, has been the power supply, thus the regulated shunt issues and the capacitors right?
what else has been a major issue? could you tell in short?
thank you for your time
Angelo e
There is not a single issue in Doede's basic kit.
Wether you tweak it or not, it remains a very good device.
Wether you tweak it or not, it remains a very good device.
as i will try anything
best i used in this position is https://ie.farnell.com/jsp/search/productdetail.jsp?SKU=2112915
http://ie.farnell.com/wima/smdtc04220tb00kq00/cap-film-pet-2-2uf-63v-smd/dp/1890111RL
smd film caps either 1uf or 2.2 there wasnt much difference bettween the 47uf muses and tantalums of various sizes
the smd 2.2uf film cap is also very impressive as an output cap
so basically is the issue of power supply... that is not part of the Doede's basic kit...
Thanks for your enthousiasm and interest. I see though, that your questions can also be solved, by reading my website. there is a lot of information and explains quite some things. this thread is a nice place where advanced DIY are sharing very nice tweaks, both on the dacs as well the power supplies (which are also a basic kit part.)
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Interesting! Which different caps did you try here and how did they compare? Did you find they made an obvious difference?
Also, remind me, which regs are you using on the dac board?
Please note, there never was an issue with Doede's Design. What were/are discussed here are an individual's preferences. i.e, to maximise the extremely best of what are already best DAC design I have heard!
Why don't you do yourself a favour by going through the literature on DDDAC.com? This thread will be very useful if and only if you would like getting the hands dirty and further experimenting to suit your setup, and matching synergy? Getting people to spoon feed what is already little effort needed seems you might not be a diy type of individual. 🙂
The power supply is not an "issue", doede's power supply and on board regulation are already very good.
I'm using it unmodified (with 2 boards and balanced outputs) and I love what I hear.
But tweakers here seem to have found room for improvement from different supply solutions.
Anyway, first place to start is doede's web site:
DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit
Wish you good reading!
Edit: chanh was quicker... We seem to say exactly the same 😉
Edit 2: doede was even quicker! Damned...
I'm using it unmodified (with 2 boards and balanced outputs) and I love what I hear.
But tweakers here seem to have found room for improvement from different supply solutions.
Anyway, first place to start is doede's web site:
DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit
Wish you good reading!
Edit: chanh was quicker... We seem to say exactly the same 😉
Edit 2: doede was even quicker! Damned...
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I have given some thoughts of this over night, still I wonder there must be a valid reason for 47uf to be at those places? I was wanting to try out Vishay MKP 0.068uf but it might not be adequate? Perhaps Doede or someone could elaborate more about these two critical caps, please?
it is 47 uF for reasons of setting the right low frequency corner for the coupling of the bias circuit. you can use lower values, than the bias will vary with any low frequency component from the power supply. if you remove them, the DC at the output is immediately there. with the 47 uF it takes like a good second. showing a low freq roll of below few hundre mHz... hope this helps?
found very little difference between various caps Electrolytic between 47uf and 300uf
im not going to say theres no difference as ive only one dac and it takes me a few mins to change out the caps
i did try without caps too and it didnt sound bad but that was just curiosity
the film caps produce a little cleaner more detailed sound
which is right up my street
the film caps on the pos output sounds more like using pos and neg without the other possible issues
im using lifepo4 cells to power direct to dac chip using only 0.1 uf decoupling caps its by far the best tweak for me followed by using z-foils as output resistors and i2s resistors and also the 2.2 uf smd film cap as output cap
Doede's power supply has no issue, it's working as expected.
Everything is tweakable, but remains working out of the box.
Everything is tweakable, but remains working out of the box.
Thank you for patiently answering some of my questions, collectively speaking, I am trying to deside which DAC to get involved with, since I was the owner of another apparatus, the "famous" 24/192 (Experience with this DIY DAC ?) china motherboard LM DAC3, which I gave to a friend, and thus the interest. Sorry if I even remotely have given the impression of a lazy to read all this valuable stuff, man. I will, I just wanted to have some exposure before I start focusing on it.
BTW how does one acquire the kit?
regards
angelo e
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I've put the unregulated powersupply in the box.. 🙂
In my case the powersupply uses a 2x18V secondaries transformer (measures 19.3V). After Rectifier, there remains 15.6VDC and after serial common mode input choke, there remains 14Vdc. I use a 25 Ohm bleeder, which brings the voltage down to 12.2 Vdc when connected to the DDDAC. The PS draws 17Watt, which loads the input choke up to just over 1 amp, which should make it work quite nicely. Sounds wonderfull, much more analogue.
I use the chassis as a heatsink for the bleeder which gets up to about 50C. The chokes get up to about 45C, (warmer then I expected). Ambient temp is quite high here at the moment, but the lid isn't even on yet.
Let me know if you want to know more or have any suggestions.
In my case the powersupply uses a 2x18V secondaries transformer (measures 19.3V). After Rectifier, there remains 15.6VDC and after serial common mode input choke, there remains 14Vdc. I use a 25 Ohm bleeder, which brings the voltage down to 12.2 Vdc when connected to the DDDAC. The PS draws 17Watt, which loads the input choke up to just over 1 amp, which should make it work quite nicely. Sounds wonderfull, much more analogue.
I use the chassis as a heatsink for the bleeder which gets up to about 50C. The chokes get up to about 45C, (warmer then I expected). Ambient temp is quite high here at the moment, but the lid isn't even on yet.
Let me know if you want to know more or have any suggestions.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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