Salas SSLV1.3 UltraBiB shunt regulator

diyAudio Chief Moderator
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Btw what do you think of the 4V vref circuit in Soekris?... Is it plausible that vref capacitance was lacking? (3*100uF + 47uF MLCC) I heard a huge difference after I added 3*1500uF polymer caps per rail - much fuller low end and more naturalness/dynamics all-round. Even my noisy laptop soundcard is now more "analytical" than dam1021, though of course lacking in real low-level details.

Looks like rev2 with 470uF polymer cap added to each rail. I think rev2 comes with 47uF each rail out of the box. Spikestabber recently added caps to his rev2 (or maybe rev1) and had great subjective results. Maybe Dimdim would be interested in trying the mod :D

The filter caps I was worried about are the 4 at the top left corner. I think the 2 to the right are for 5V LDO and another RC filter so probably has their place on the board... Anyways, will probably leave them there as is since they don't interfere with UltraBiB :)

Anyways, when tweaked ladder sounds this good who needs snub college stuff named ΣΔ :D
 
Looks like rev2 with 470uF polymer cap added to each rail. I think rev2 comes with 47uF each rail out of the box. Spikestabber recently added caps to his rev2 (or maybe rev1) and had great subjective results. Maybe Dimdim would be interested in trying the mod :D

It's a 0.02% Rev.1 with the low-res mod and the caps that are visible. I don't really remember their capacity - I'll have to look once I get a chance.
 
Anyways, when tweaked ladder sounds this good who needs snub college stuff named ΣΔ :D

Lol, I'm sure some ΣΔ also sounds great!

It's a 0.02% Rev.1 with the low-res mod and the caps that are visible. I don't really remember their capacity - I'll have to look once I get a chance.

the marking seems to say 471 which is why I guessed 470uF. Might be worth trying some more capacitance :p
 
I’m guessing that more pleasurable sound isn’t your only motivation at this point :D Sanity and seriousness aside, for me it’s all too easy to “obsess” over a build that I seem to be have responsibility for and enjoy it (all too much). I hope no one else shares this temperament :eek:

But, Dimdim, you should try the cap mod in all seriousness. If only for the greater good of the Soekris community (I mean it’s easy and many of us hear a great improvement)
 
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One more DCG3 upgraded with ultra BIB.
Not that DCSTB was not up to the task, but ultra BIB gave a noticeable uplift to the sound.
 

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Have two 1.3 boards and minikits on the way (hopefully) from last GB. Would like to try one full board as a replacement PS for a dual-mono DAM1121 build. Salas, am I correct in the following:

DAM1121 positive 5V Digital rail is 250mA typical with a max of 350mA. So, powering two DAMs from a single positive rail of the 1.3 with plus 100mA headroom would be a 800mA target current. R1 would then be 0.75R 2W for that rail.

DAM1121 positive 5V Analog rail is 20mA typical with a max of 50mA. So, powering two DAMs from the other positive rail on a 1.3 board with plus 100mA headroom would be 200mA target current. R1 would be 3R 0.5W(?)for that rail.

The same calculation for the DAM1121's -5V rail, i.e, 3R 0.5W (?) for the R1 on the negative rail.

Does the 1K value for R9 still stand in this configuration? At least on the 800mA rail? But not necessary on other two rails. Total 'Spare' current is 300mA.

Do capacitor values in the build guide still pertain for this configuration? Any tips on which brand and values for this application welcome :)

Re transformer, using an R-core at 9VAC, the current draw is around 10.8VA so could I get away with a 30VA trafo? Or is 40VA a safer choice here?

Or are my sums off?!

Also, if I have the real estate to accommodate two R-cores is there any advantage to separating the DACs trafo from the rest - rest in this case is a uC and its attendant display, IR rcvr, rot enc etc as well as a 3V3 supply for an USB/I2S XMOS board.
 
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diyAudio Chief Moderator
Joined 2002
Paid Member
Does the 1K value for R9 still stand in this configuration? At least on the 800mA rail? But not necessary on other two rails. Total 'Spare' current is 300mA.

Do capacitor values in the build guide still pertain for this configuration? Any tips on which brand and values for this application welcome :)

Re transformer, using an R-core at 9VAC, the current draw is around 10.8VA so could I get away with a 30VA trafo? Or is 40VA a safer choice here?

Or are my sums off?!

Also, if I have the real estate to accommodate two R-cores is there any advantage to separating the DACs trafo from the rest - rest in this case is a uC and its attendant display, IR rcvr, rot enc etc as well as a 3V3 supply for an USB/I2S XMOS board.

- It stands (for the 800mA case)
- They do pertain. Currently on Mouser C1 Nichicon LKS 6800uF/25V C2 Nichicon UKZ 470uF/25V C3 Nichicon UES 47uF/50V
- Can get away with 30VA
- Sum and R1 values are correctly calculated
- Not bad to separate in theory but you must ask Dam experts if it practically pays off in this case or not
 
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Thanks.
Subjectively, have you found a difference with the rcore trafos vs toroids?


nash

I did extensive tests with toroids and r-cores and these are more silent (less hum) they produce much clearer and extended highs and naturally that also results in better resolution in the lower octaves.

Toroids have subjectively more present bass but with less detail and extension.

Unfortunately I can not find any r-core distributor in europe so I am now stuck with toroids.

PS: beware of chinese r-cores as IMO they do not regulate properly... not well built.
 
Salas I'm serious. Using HQPlayer poly-sine-xtr filter to upsample to 353/384Khz to bypass onboard FIR1 (and NS5 noise shaping though I'm not sure if makes an audible difference), dam1021 improves extremely dramatically in naturalness. The harshness in the higher frequencies is reduced to extremely low levels if not completely gone (it'll take someone who spent more time in concert halls recently to claim perfection...). But even the SoX/SSRC filters which are slightly shorter (but still x8 to x150 times longer than the best dam1021 FPGA filters) make a huge improvement. You need to have a listen when you get the chance :)
 
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