DDDAC 1794 / 12V PSU
Hi there,
I am using standard 12V PSU kit.
Wondering whether I could substitute a filament choke in position R2 (0.1 ohm 5W)
Question - What would the max choke DCR allowance be in this R2 position ?
I have a Hammond 300mH, 1A choke, 6 ohm DCR.
DAC is using three deck so approximately 300ma would pass through choke. This would cause a voltage drop around .3 x 6 = 1.8V would this be too much resistance to regulate properly ?
Cheers Johno
Hi there,
I am using standard 12V PSU kit.
Wondering whether I could substitute a filament choke in position R2 (0.1 ohm 5W)
Question - What would the max choke DCR allowance be in this R2 position ?
I have a Hammond 300mH, 1A choke, 6 ohm DCR.
DAC is using three deck so approximately 300ma would pass through choke. This would cause a voltage drop around .3 x 6 = 1.8V would this be too much resistance to regulate properly ?
Cheers Johno
Hi Johno, two chokes will definitively not work. The point is not the 300mA, but the high currents to charge the first capacitor. Voltage will drop dramatically. You can simulate this with the free PSU2II program from Duncan.
the good news: if you replace the SECOND 0,1 Ohm with this Choke, you will have just sufficient voltage left over for regulation and it filters very well.
just give it a try and let us know how it went, ok ?
12V PSU with Hammond 159ZA, 300mH CHOKE
Ok tried the Hammond 300mH, 1A choke, 6 ohm DCR in lieu of R2 (0.1Ohm) in 12V PSU.
Bad news the v drop is too much the voltage after the choke is 15.2V with a 230V input, this is with a 3 tier DAC. Now I assumed the current consumption was approximately 310ma and Duncan PSU modelling shows around 17V output after filter with a x10 reduction in ripple compared to the 0.1ohm. But my current tongue tester indicates a current load of around 450ma ? Anyway the PSU would not regulate under load with 15V at the output of the filter. Such is life !
Next option in the junk box was a Radio shack 270-030 noise filter, 0.7uHy, 4 amp choke, 91mOhm. These are used in motor vehicles for AM noise suppression. I wired this in series with R2 on an outrigger all voltages returned to normal as this is an iron ferrite snubber choke it can't be modelled correctly in Duncan PSU software ?
So in conclusion it would appear the Hammond 6 ohm DCR is unworkable if using multiple tier DAC perhaps with single tier it may work ok, pity as the 300mH choke basically reduces the ripple to less than 10mV. This is a 10 fold decrease in ripple compared to R2, 0.1ohm
Cheers Johno
Ok tried the Hammond 300mH, 1A choke, 6 ohm DCR in lieu of R2 (0.1Ohm) in 12V PSU.
Bad news the v drop is too much the voltage after the choke is 15.2V with a 230V input, this is with a 3 tier DAC. Now I assumed the current consumption was approximately 310ma and Duncan PSU modelling shows around 17V output after filter with a x10 reduction in ripple compared to the 0.1ohm. But my current tongue tester indicates a current load of around 450ma ? Anyway the PSU would not regulate under load with 15V at the output of the filter. Such is life !
Next option in the junk box was a Radio shack 270-030 noise filter, 0.7uHy, 4 amp choke, 91mOhm. These are used in motor vehicles for AM noise suppression. I wired this in series with R2 on an outrigger all voltages returned to normal as this is an iron ferrite snubber choke it can't be modelled correctly in Duncan PSU software ?
So in conclusion it would appear the Hammond 6 ohm DCR is unworkable if using multiple tier DAC perhaps with single tier it may work ok, pity as the 300mH choke basically reduces the ripple to less than 10mV. This is a 10 fold decrease in ripple compared to R2, 0.1ohm
Cheers Johno
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Thanks for feedback - if you really want to experiment with the choke, you could change the transformer to a 2x18V version….
Hi there,
Appreciated if anyone can answer my question. Should I go for hifiberry or WaveIO if sound quality is the major consideration.
The WaveIO and the RPi+HifiBerry serve to very different functions. The WaveIO converts from USB audio to I2S, so it provides an USB audio input to the DDDAC.The RPi+HifiBerry work as a network music streamer and music server (depending on software and attached storage) with an I2S output to the DDDAC. You'll have to decide first which of the two you want.
Regarding sound quality, I felt the RPi+HifiBerry sounded better when I changed from the WaveIO. But that was not a systematic and controlled comparison, and I may have been biased by the "shiny new toy effect".
I am pretty sure that Audio Creative will also sell WaveIO boards if you ask them. I might also have one or two floating around. PM me if you want one.
If you use a Kali reclocker you can get equal sound quality from the Wave IO as an RPI. Most folk I know prefer the flexibility of their Mac or PC as source rather than the limitations of the RPI available software. I'm talking Netflix, You Tube, Amazon Prime and internet radio stations among others.
Oh, and the newer Kali boards do not seem to work with the WaveIO anymore. Allo do not know why.
Hi every one!
I am starting to build my dddac. From the reading this thread I came to the following configuration. It seams it will give the best sound quality. I would really appreciate some advices and experiences on this build.
1. Configuration
ODROID C1+ (or BBB) i2s —> isolator (from diyinhk) —> external clock (from jlsounds.com) —> directly 4 decks (no main board)
Will Odroid do the conversion to the Right Justified?
What possible issues I can run into with this configuration?
2. Powering
I need 3 sources of power. I think this is the key point for sq.
(4 boards, may be 8 later)
Odroid - 5v, 2A
Clock - 5v, 150mA
4 decks - 12v, 400mA
1 What is your experience for the best power supplies (like salas or Sjostrom or choke Etc?)
2 Tubed psu (6c5s)? (CLCLC From lampizator I already have)
3 Battery?
4 I also heard very good feedbacks about using ultra caps (2x2.7v, 3000F) in psu, has someone had an experience with?
3 Output stage
By now I have duelund 1uF 630v caps and
I understood that tubed stage its not worth it and the best option is the sowter (or other) trannies
What is your experience, what would you recommend?
I am starting to build my dddac. From the reading this thread I came to the following configuration. It seams it will give the best sound quality. I would really appreciate some advices and experiences on this build.
1. Configuration
ODROID C1+ (or BBB) i2s —> isolator (from diyinhk) —> external clock (from jlsounds.com) —> directly 4 decks (no main board)
Will Odroid do the conversion to the Right Justified?
What possible issues I can run into with this configuration?
2. Powering
I need 3 sources of power. I think this is the key point for sq.
(4 boards, may be 8 later)
Odroid - 5v, 2A
Clock - 5v, 150mA
4 decks - 12v, 400mA
1 What is your experience for the best power supplies (like salas or Sjostrom or choke Etc?)
2 Tubed psu (6c5s)? (CLCLC From lampizator I already have)
3 Battery?
4 I also heard very good feedbacks about using ultra caps (2x2.7v, 3000F) in psu, has someone had an experience with?
3 Output stage
By now I have duelund 1uF 630v caps and
I understood that tubed stage its not worth it and the best option is the sowter (or other) trannies
What is your experience, what would you recommend?
Sell those Duelunds and get yourself a pair of trannies. I don't know about the volume control in your system, but using a transformer volume control for this is the best choice in my opinion. It takes the balanced signal off the DAC chips and feeds it directly to your power amps -- very easy and clean! The Sowter 9335 are very good for this in the DDDAC.
I know there are a lot of pages in this thread but if you search back through some of the pages you can get a good idea of what others have experimented with. I used an oversized toroid (125va) I can’t remember exactly what kind of filtering I used, may have been LC or perhaps RC. I then used DEXA regulators right at the mother board input connectors for the +5 volt and 12 volt inputs.
I read this forum from time to time for almost 2 or 3 years though I did not read everything. From what I learned from here is that battery power is the simplest and cleanest solution. (with allo isolator and reclocker) There should be no problem for BBB as it will be isolated. I already have clclc with tube rectifier (see pic) so it will not be difficult co compare. I don't have much knowledge in electronics so I
hope someone could point me something I don't see as with duelunds.
Also probably it is useful to summarize the best configuration every now and then in such a long thread. Dexa are interesting, thanks!
hope someone could point me something I don't see as with duelunds.
Also probably it is useful to summarize the best configuration every now and then in such a long thread. Dexa are interesting, thanks!
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Here is mine psu. R-core trafo’s, rectifier bridges from Sjøstrøm audio, chokes from Lundahl and stock psu’s (without stock trafo’s). I have tested my dac against expensive that cost twice, and dddac is still my choice. Overall sound is very good, and it is dynamic as hell.
Funky music played loud simply blow you away.
Funky music played loud simply blow you away.
