My Alix/mpdpup is connected to the dddac with two boards.
I use the dddac power supplies 12v and 5v with minor modifications (black gate non polar antiparallel on output, film cap not soldered and elna silmic for the big caps.)
The alix is fed with a tent power supply.
Two extra boards with sowters are on their way to me (hopefully soon).
I also plan to mount tent shunt regulators on the dac boards, I wonder what that will do with the sound?
The sound is already pretty good and is a close match to my cd player/ dac combo but I hope this will improve with the planned modifications to exceed the cd player/dac performance ( I have a feeling that it will)
Do let us know how the modifications go. I for one am very interested in how far the DDDAC can be taken.
starting to put together the 5v and 12v power supply kits.
power supply kits done. now time to wire it all back up and see if it brings any improvements!
also i relised my preamp is fully balanced and has balanced input. so if I wanted to wire the dddac board to output balanced, do I need output capacitors?
Cheers!
An externally hosted image should be here but it was not working when we last tested it.
power supply kits done. now time to wire it all back up and see if it brings any improvements!
An externally hosted image should be here but it was not working when we last tested it.
also i relised my preamp is fully balanced and has balanced input. so if I wanted to wire the dddac board to output balanced, do I need output capacitors?
Cheers!
hi Tuyen, nice work so far !
yes you need capacitors if there is a connection between both systems ground. this is normally the case, one way or the other. if not you can try without, as long as the amp can handle a few mV DC. that is what you will measure, please check, between POS and NEG terminal....
oh, do not forget to place the jumper on the WaveIO board to "EXT"
yes you need capacitors if there is a connection between both systems ground. this is normally the case, one way or the other. if not you can try without, as long as the amp can handle a few mV DC. that is what you will measure, please check, between POS and NEG terminal....
oh, do not forget to place the jumper on the WaveIO board to "EXT"
Hi tuyen,
i have the dddac woking with balanced outputs, no capacitors, no problems at all.
Regards
Hi, I am ordering the parts for the power supply, for some reason farnell doesn't have 25VAtoroid transformers, only 30VA would these work too? They don't seem to have the handy square casing:
Toroid Transformers at Farnell
Okey nvm, I'm obviously rather bad at finding stuff at Farnell, it worked now and I got the right ones I think:
25VA transformers on Farnell
Toroid Transformers at Farnell
Okey nvm, I'm obviously rather bad at finding stuff at Farnell, it worked now and I got the right ones I think:
25VA transformers on Farnell
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Please don't take this question as a criticism, I am just curious about how these things work:
Would there be less need for big output capacitors or good transformers if the DAC were designed in a more complex way?
Or in other words: is this DAC intentionally expensive? Could similar results come from a design that required less expensive parts?
I really love this design for its simplicity, but the suggestions for ~150e worth of capacitors or ~600e worth of transformers struck me as odd, and leave me wondering about the reason.
Would there be less need for big output capacitors or good transformers if the DAC were designed in a more complex way?
Or in other words: is this DAC intentionally expensive? Could similar results come from a design that required less expensive parts?
I really love this design for its simplicity, but the suggestions for ~150e worth of capacitors or ~600e worth of transformers struck me as odd, and leave me wondering about the reason.
Testing the DDAC
Hi All,
First oF all must acknowledge what a geat guy Doede is to deal with!
Just got the dac going for an initial run on the bench top with the assembly on a mdf board to sort out/ trouble shoot if required. My raw supply is a bit over the top. Consists of two 30Va EI transformers with a secondary of 22v centre tapped. For the 5V supply, I set up a full wave supply feeding two 25mh (2 amp) chokes followed by 6800mfd which then feeds into Doede's psu boards. For the 12V supply its bridge across the full 22V feeding a 0.3H (1.1amp) choke feeding into 12000mfd and then into the PSU board for stabilsation. Diodes are MBR10100 single diodes to give me the flexibility.
Initial raw supply tests under resistor load gave a clean 7mv ripple before the board for the 12v supply and about 25mv for the 5V supply.
I used Duncan amps PSU modeler to ensure that current loading is well above the critical level. Used extra power resistors to do this.
Tested the sound with headphones ( AKG702, silver wire harness) and Schiit lyr headphone amp. Sounds great, but Foobar settings may need checking as there are random scratchy noises when playing. Will try to post photos over the next few days.
Cheers!
Ravi
Hi All,
First oF all must acknowledge what a geat guy Doede is to deal with!
Just got the dac going for an initial run on the bench top with the assembly on a mdf board to sort out/ trouble shoot if required. My raw supply is a bit over the top. Consists of two 30Va EI transformers with a secondary of 22v centre tapped. For the 5V supply, I set up a full wave supply feeding two 25mh (2 amp) chokes followed by 6800mfd which then feeds into Doede's psu boards. For the 12V supply its bridge across the full 22V feeding a 0.3H (1.1amp) choke feeding into 12000mfd and then into the PSU board for stabilsation. Diodes are MBR10100 single diodes to give me the flexibility.
Initial raw supply tests under resistor load gave a clean 7mv ripple before the board for the 12v supply and about 25mv for the 5V supply.
I used Duncan amps PSU modeler to ensure that current loading is well above the critical level. Used extra power resistors to do this.
Tested the sound with headphones ( AKG702, silver wire harness) and Schiit lyr headphone amp. Sounds great, but Foobar settings may need checking as there are random scratchy noises when playing. Will try to post photos over the next few days.
Cheers!
Ravi
Hello.
The suggested capacitors are really "highest available quality".
You can probably achieve excellent performances with less expensive ones.
An interesting reading, subjective opinion of course, but it gives a good idea of relative audio quality between capacitors:
Humble Homemade Hifi
On the "budget side", Jantzen audio (Silver or Superior Zcap) should give very good results for around 30/35 euros a pair.
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Thanks a lot, that makes the entire set be in a reasonable price range.
I am still a bit unclear about when a transformer is needed, it reads like it is optional but recommended. Does it depend on the (pre-)amplifier that comes after the DAC? What should I look for when matching the DAC to an amplifier?
I am still a bit unclear about when a transformer is needed, it reads like it is optional but recommended. Does it depend on the (pre-)amplifier that comes after the DAC? What should I look for when matching the DAC to an amplifier?
Doede will explain in more detail I'm sure but the transformers aren't needed at all. If you do want to try the transformers though you will need at least 4 DAC boards.
I currently have 4 DAC boards with the Mundorf Caps, I'm considering the transformers as the next step. As it is in my system the DDDAC sounds excellent.
If I'm not mistaken, the original purpose of the tranformers was to boost the output signal from 1.25V to 5V.
Depending on your (pre)amp, 1.25 may be far enough but some setups could benefit from higher input level.
Yep that about sums it up Ian. The single board had scale and an analogue presentation. The extra boards added a little more depth, and a good deal more subtlety to the texture