You can try Pieter Treurniet from Tribute. He can wind volume transformers at order if you want. Sowter also has some in stock and not expensive.
Groeten,
Salas 8VDC Shunt PS
My BF862 Buffers to the Cinemags have broken in giving more detail and drive from a one board DDDAC. +/- 12VDC 200ma CCS Salas shunt regulators are supplying about 60ma to the buffers. More about this in a future entry. I am ready to try other upgrades and tweaks.
I discovered that a 200ma CCS Salas does not sound right trying to supply 12VDC to the DDDAC. A 1 amp 12VDC linear regulator sounds much better - presumably because it has sufficient current available.
I upped the Salas to 250ma CCS and adjusted the voltage to 8VDC. I lifted the 10uh inductors after the LF80 regulators and ran individual wires from the Salas to the DDDAC board into the inductor holes to the PCM1794 chips. I didn't remove any caps. I also lifted the 10ohm resistors from 12VDC source and connected another wire from the Salas to the 12VDC input. 8VDC is more than enough to satisfy the three 3.3VDC regulators.
The improvement in sq was immediate. The sound is more analog and lively. While the entire musical spectrum is more pronounced, the deep base improved the most. No negatives. I recommend that anyone using a shunt power supply for the 12VDC to the DDDAC try to use it as an 8VDC supply and bypass the LF80. I don't know if this would work as well with a series regulated voltage power supply. Next, I'm going to replace the three LF33 regulators with Belleson SPM78's which are only 22mm tall (not including pins) and cost $36USD each.
My BF862 Buffers to the Cinemags have broken in giving more detail and drive from a one board DDDAC. +/- 12VDC 200ma CCS Salas shunt regulators are supplying about 60ma to the buffers. More about this in a future entry. I am ready to try other upgrades and tweaks.
I discovered that a 200ma CCS Salas does not sound right trying to supply 12VDC to the DDDAC. A 1 amp 12VDC linear regulator sounds much better - presumably because it has sufficient current available.
I upped the Salas to 250ma CCS and adjusted the voltage to 8VDC. I lifted the 10uh inductors after the LF80 regulators and ran individual wires from the Salas to the DDDAC board into the inductor holes to the PCM1794 chips. I didn't remove any caps. I also lifted the 10ohm resistors from 12VDC source and connected another wire from the Salas to the 12VDC input. 8VDC is more than enough to satisfy the three 3.3VDC regulators.
The improvement in sq was immediate. The sound is more analog and lively. While the entire musical spectrum is more pronounced, the deep base improved the most. No negatives. I recommend that anyone using a shunt power supply for the 12VDC to the DDDAC try to use it as an 8VDC supply and bypass the LF80. I don't know if this would work as well with a series regulated voltage power supply. Next, I'm going to replace the three LF33 regulators with Belleson SPM78's which are only 22mm tall (not including pins) and cost $36USD each.
Attachments
Supersurfer,
The Salas outputs are soldered to the Sensor inputs underneath the connectors. Sensor wires from 3 destinations could create problems.
I plan to upgrade the cooling using the aluminum chassis when I get back up North in late May. I will also increase the 8VDC Salas to 300ma. The CCS on the 8VDC is the only device too hot to touch, so I will be adding another cooling fin to this now. Meanwhile I will just enjoy the music.
Thanks for your input.
The Salas outputs are soldered to the Sensor inputs underneath the connectors. Sensor wires from 3 destinations could create problems.
I plan to upgrade the cooling using the aluminum chassis when I get back up North in late May. I will also increase the 8VDC Salas to 300ma. The CCS on the 8VDC is the only device too hot to touch, so I will be adding another cooling fin to this now. Meanwhile I will just enjoy the music.
Thanks for your input.
Yep, a switching power supply
Thanks, Supersurfer and WalterW is right that brown PCB is a switching power supply for the xmos i2s board usb power, a temporary solution that i have lying around. The dac and motherboard is supplied with a dual output psu based on TI TPS7A47 regulator that has kelvin sensing on load thus providing quite a fast and stable voltage and suppose to be ultra low noise though I can't verify it.
So far differential output with direct connections is sounding best connected to my balanced preamp/headphone amp. The bass sounds better define,more punchier, cleaner overall and of course louder than rca out.... I guess the higher voltage you get going balanced compared to single ended is the main contributor for better sq. Not sure how much better if I were to go with the sowters though that is a bit costly to pursue.
Still waiting for my pcm1794 dac chips plus soic to dip adapter boards and other stuff to arrive before I could try and play around with just stacking dac chips and other stuff to fool around before I settle down with a final built within this couple of weeks/months hopefully sooner than later.
Hi carlsor nice stuff you've got going there....I'm very much interested in the buffer circuit you're using there. Hopefully you'll post up the schematics and part list for the buffers and maybe I can do some comparisons between going the buffers way or dac stacking or both to see which would yield the better overall sq.
Bypassing the inductors should give it a slight improvement in sq and try giving the analog section more than 8 volts(8.6 to be exact) if you can or 9 volts if you can't(stay within 9v though) since that would yield better sq and the dac still can run cool to the touch.
Acko S03
I added the Acko S03 reclocker/isolator to the pi and it has improved the sound noticieably. Again, more definition, more detail and the bass a little better. Imaging has also gained some focus. Still tweaking it with Acko's help.
I did replace the Lundahl 1684's with the Cinemag 15/15b's. I'm not sure about that change. The Cinemags are smoother and the highs are less in your face (Carlsor summarized it best: very polite sound). But I seem to have lost some dynamics in the exchange. The dac doesn't seem to play as loud (for the same volume setting), which might be why it sounds less dynamic (I have a passive preamp so I need all the gain I can get). I'm using the 10k resistors, I'll try a lower one as Doede recommended before.
I added the Acko S03 reclocker/isolator to the pi and it has improved the sound noticieably. Again, more definition, more detail and the bass a little better. Imaging has also gained some focus. Still tweaking it with Acko's help.
I did replace the Lundahl 1684's with the Cinemag 15/15b's. I'm not sure about that change. The Cinemags are smoother and the highs are less in your face (Carlsor summarized it best: very polite sound). But I seem to have lost some dynamics in the exchange. The dac doesn't seem to play as loud (for the same volume setting), which might be why it sounds less dynamic (I have a passive preamp so I need all the gain I can get). I'm using the 10k resistors, I'll try a lower one as Doede recommended before.
Attachments
This is mine version of the DDDAC, I’m not really in electronics , but Doede, this forum and audio-creative.nl convinced me that it was possible for somebody who’s a little bit handy and with a wellstation.
After contact with Doede I ordered it, use a lot of ideas from this forum. Tantalum, short spacers, the Modu Case, Cinnemag and build it. It’s now playing for a week and it sounds great.
I play with a Sonos, compare it with my 20 year old Wadia 12 which I want to replace. The DDDAC does every thing better, more details, 3D, more music.
I only had to found a better way to place the tumble switch.
This also proofs the brilliant design of the DDDAC: Someone has not to be a electronic expert to build, but it also gives a challenge to real tweakers.
Go on and thank you all. AcvB
After contact with Doede I ordered it, use a lot of ideas from this forum. Tantalum, short spacers, the Modu Case, Cinnemag and build it. It’s now playing for a week and it sounds great.
I play with a Sonos, compare it with my 20 year old Wadia 12 which I want to replace. The DDDAC does every thing better, more details, 3D, more music.
I only had to found a better way to place the tumble switch.
This also proofs the brilliant design of the DDDAC: Someone has not to be a electronic expert to build, but it also gives a challenge to real tweakers.
Go on and thank you all. AcvB
Attachments
Hi, the idea is from WalterW, it's the modu Galaxy Maggiorato GX388 330 x 280 mm, I found on post 881, 885, and 896. I also order feet and a special 10mm front. This give some problem with the tumbler switch because the thread of the switch is 9 mm, this had to be solved yet. I used 4mm under the main board and 7 mm between mainboard and first deck to keep the high below 80mm. I used to solder one red capacitor a little bit aslope to avoid contact with a solder above, better use 8 mm. It's rather expansive but it's a nice case: feet, extra front and transport 106 Euro, order at ELTIM audio BV, Europe's main supplier of original MOREL drive units and related products., gr, AcvB
Not at all what I meant ...
I have the original board.
I have no interest in using the SPDIF input.
I might go with eight DAC boards in the future,
Would it be worthwhile to go ahead and get the new motherboard?
I have been working on a new phono stage so have done nothing with the DAC from when I first assembled and it did not work. Wondering if I should start with the new board sine I am basically starting over.
Trying to get absolute clarification on how to use the new board. Is it ONLY for those who want the SPDIF input?
Thanks,
I have the original board.
I have no interest in using the SPDIF input.
I might go with eight DAC boards in the future,
Would it be worthwhile to go ahead and get the new motherboard?
I have been working on a new phono stage so have done nothing with the DAC from when I first assembled and it did not work. Wondering if I should start with the new board sine I am basically starting over.
Trying to get absolute clarification on how to use the new board. Is it ONLY for those who want the SPDIF input?
Thanks,
