ive only tried amanero and jlsounds oem also in this position
i suppose some of the shunts the guys use here should be good too maybe they will advise
well i assumed that if your using a transformer was to decouple dc voltage whilst avoiding using a cap (like the dddac has) and buffer
im not familar i was thinking more like the pass b1 buffer or http://hifisonix.com/wordpress/wp-content/uploads/2015/01/UBx.pdf
I had one a while back, but at some point I traded it for a tube amp.
It was pretty transparent, sometimes I wish I had kept it. I had an older version of the S&B one.
A few guys make them, S&B, Sowter, Silk and Intact (Dave Slagle)
If I were to buy one now, it would probably be the Intact one.
It was pretty transparent, sometimes I wish I had kept it. I had an older version of the S&B one.
A few guys make them, S&B, Sowter, Silk and Intact (Dave Slagle)
If I were to buy one now, it would probably be the Intact one.
I am using the SLAGLE attenuator on the output of the SOEKRIS and my phono amp.
Superior sonically to a TVC, I have used the SLAGLE and SOWTER TVCs, the autoformer is much better.
Lifetime attenuator. Get one and you will never have to think about attenuators again.
Unless you like thinking about them!
Superior sonically to a TVC, I have used the SLAGLE and SOWTER TVCs, the autoformer is much better.
Lifetime attenuator. Get one and you will never have to think about attenuators again.
Unless you like thinking about them!
Hi,
I bought the v3 and some high precision regulators.
For mois, what I understood :
Vref : 4 caps like 470 or 680 uF at +-4V reg or 16 caps directly to the switch, or both ?
Caps low ESR like Nichicon FP, others better ?
0.1 ohm bypass resistor and jumper to the other
Am I right ?
I also saw it was possible to replace the RC output filter cap : can you advice caps value and Quality ?
Are there other simple mods that can be implimented ?
Many thanks in avance
Jules
I bought the v3 and some high precision regulators.
For mois, what I understood :
Vref : 4 caps like 470 or 680 uF at +-4V reg or 16 caps directly to the switch, or both ?
Caps low ESR like Nichicon FP, others better ?
0.1 ohm bypass resistor and jumper to the other
Am I right ?
I also saw it was possible to replace the RC output filter cap : can you advice caps value and Quality ?
Are there other simple mods that can be implimented ?
Many thanks in avance
Jules
The rev 2 and rev 3 vref buffers are different from the rev1 design that really needed modification, unless you fully understand the vref buffer circuit I don't recommend you touch it....
Dear Soren,
I saw the mod very well documenter :https://hifiduino.wordpress.com/2015/07/12/soekris-dac-modding-vref/
As I'm quite used to that kind of solder mod, does it sonicaly present an interest in rev3 ?
Same for resistors regulators mod : was it implimented in the rev3 ?
I saw the mod very well documenter :https://hifiduino.wordpress.com/2015/07/12/soekris-dac-modding-vref/
As I'm quite used to that kind of solder mod, does it sonicaly present an interest in rev3 ?
Same for resistors regulators mod : was it implimented in the rev3 ?
I have been running without any cap at all for a few months and I've had zero problems. I am just a reckless tinkerer though so don't take my word alone!
Hello Soren,
I have one board Rev1 0,02% and one board Rev3 0,02% and want to go the true balanced way. Can you tell me what to change on board Rev1 so that it is almost the same as the Rev3 board and I can use both in true balanced mode? The wiring of two boards for balanced mode shouldn't be the problem but I need to know the difference on Vref-Buffer and how much capacitance I have to add on each shift-register. SMD soldering is not that problem for me.
I have done the factory mod, but as you said recently the vref-buffer in Rev3 is different to vref-buffer on the other two Rev's.
I love this dam1021 really much but I don't want to buy a second board from Rev3. I hope you can give me an answer.
Thank you in Advance
Johannes
I have one board Rev1 0,02% and one board Rev3 0,02% and want to go the true balanced way. Can you tell me what to change on board Rev1 so that it is almost the same as the Rev3 board and I can use both in true balanced mode? The wiring of two boards for balanced mode shouldn't be the problem but I need to know the difference on Vref-Buffer and how much capacitance I have to add on each shift-register. SMD soldering is not that problem for me.
I have done the factory mod, but as you said recently the vref-buffer in Rev3 is different to vref-buffer on the other two Rev's.
I love this dam1021 really much but I don't want to buy a second board from Rev3. I hope you can give me an answer.
Thank you in Advance
Johannes
Almost the same here: I have a rev. 2 combined 0.02/0.01 board. I'd like to go balanced - what do I do? Can I just buy rev. 3? Do you happen to have 1 hybrid board rev. 2 still left in stock?
Lucho
The holes are nom 26 mil - 0.66 mm diameter, most smaller caps up to Ø10 are spec'ed at 0.5-0.6 mm and should fit....
Btw, I forgot to mark + and - on the PCB, will mark a picture at some point, until then:
C166-C168, C172-C174: Plus is towards the XLR plugs.
C169-C171, C175-C177: Plus is away from the XLR plugs.
I'll recommend to verify with a multimeter....
For people who want to use two boards from different production lots in balanced mode here is how each of the four vref buffers look like from the factory:
Original rev1: 10R series resistors, 22 uF output capacitor, 330 pF feedback capacitor and 499R feedback resistor
Factory upd rev1 and prod rev2: 0.1R series resistor, 47 uF output capacitor, 499R resistors mounted in both capacitor and feedback resistor position, creating an effective 0.050R vref buffer output impedance.
Prod rev3: 0.1R series resistor, 47 uF + 3x 100 uF output capacitors, 1K00 resistor mounted in feedback capacitor position (orange), 301R resistor mounted in feedback resistor position (yellow), creating an effective 0.025R vref buffer output impedance.
Colors on attached drawing:
Red: Output capacitor.
Blue: Series Resistor.
Orange: Feedback capacitor (now used for resistors).
Yellow: Feedback resistor.
Original rev1: 10R series resistors, 22 uF output capacitor, 330 pF feedback capacitor and 499R feedback resistor
Factory upd rev1 and prod rev2: 0.1R series resistor, 47 uF output capacitor, 499R resistors mounted in both capacitor and feedback resistor position, creating an effective 0.050R vref buffer output impedance.
Prod rev3: 0.1R series resistor, 47 uF + 3x 100 uF output capacitors, 1K00 resistor mounted in feedback capacitor position (orange), 301R resistor mounted in feedback resistor position (yellow), creating an effective 0.025R vref buffer output impedance.
Colors on attached drawing:
Red: Output capacitor.
Blue: Series Resistor.
Orange: Feedback capacitor (now used for resistors).
Yellow: Feedback resistor.
Attachments
Prod rev3: 47 uF + 3x 100 uF output capacitors
Sorry Soren, you mean for each vref there are now 47 uF + 3x 100 uF (4 stacked) output capacitors?
No stacked parts, rev3 board now have an additional 3 pcs 100uF ceramic capacitors for each vref rail, see fresh pictures on soekris.dk website....