Salas, my "source" is RPI3 with discrete linear PS, but it is not a shunt one. Good power transformer and linear power supply have crucial impact on the overall sound of the system, even though I am using JLSounds XMOS which has galvanic isolation... go figure!
I bet an Ultra BiB will be even better, if you can live with the huge heatsinks... or even two Ulta BiB's — one for the RPI and one for the HDD
Hi,
I tested the reg on both "Pi3 model B" and "Pi3 model B+";
I did the similar tweaking like yours in the config file.
My "Pi3 model B" has all 3 voltages converted to linear power supply with LT3042 module; and my Pi3 model B+ is equipped with a linear PS only for 5-volt via GPIO.
but I am always in search of a better PSU by trying different options
Great! Look forward to the GB. Now to count all those pesky wallwarts that have to go....
Not pushing you, Salas, (not much
) but any idea of time to market?I also hear the difference, Salas.
I modded a Pi3 model B with linear PS for all 5.1V, 3.3V and 1.8V (a heavy modding by taking away a bunch of parts and soldered directly the wires on the corresponding test pads); it does give an excellent dynamic and soundstage and lowest noise background. I also did the software tweaking learned from the forum of course.
When something big is performing, the noise level can be heard with the official adaptor!
The other Pi3 model I have, I gave it a 5 Volt linear PS via GPIO only with a lighter transformer (40VA / 7Vac sec), it sound better than the official adaptor but not as good as the all modded version.
I modded a Pi3 model B with linear PS for all 5.1V, 3.3V and 1.8V (a heavy modding by taking away a bunch of parts and soldered directly the wires on the corresponding test pads); it does give an excellent dynamic and soundstage and lowest noise background. I also did the software tweaking learned from the forum of course.
When something big is performing, the noise level can be heard with the official adaptor!
The other Pi3 model I have, I gave it a 5 Volt linear PS via GPIO only with a lighter transformer (40VA / 7Vac sec), it sound better than the official adaptor but not as good as the all modded version.
Do it, for Mother Nature's sake. My linear psu for my PC consumes just 10 watts more than a SMPS psu and soundwise is clearly superior. Aim for 12V output, usually a picoPSU used farther down the way (or even LDOs for the bravehearts)
Although 5V output for a shunt, don't make for so much for power loss, still I think is much too much for a computer that RPi really is
I all, i have my pi3 powered by a linear psu by gpio 5v and the hifiberry digi pro powered by salas reflektor d 3.3v...
The last version of reflektor has vishay var r6, mundorf main filter and on c2 various polymer caps paralell to almost 9000uf.
It has very good sound.
I made lot of test of more power supplies and reflektor is the best. The difference between ps is very audible even between reflektor stock and mod version.
It would be great to have some salas ps to power the pi also.
The last version of reflektor has vishay var r6, mundorf main filter and on c2 various polymer caps paralell to almost 9000uf.
It has very good sound.
I made lot of test of more power supplies and reflektor is the best. The difference between ps is very audible even between reflektor stock and mod version.
It would be great to have some salas ps to power the pi also.
![IMG_20190222_214804[1].jpg](/community/data/attachments/669/669118-40f49031418fa387ceae2cb4686b102d.jpg)
What would be the best M1 and M2 transistors for DCG3?
I guess DCG3 is always below 1A.
Some random comparisons:
M1 Positive:
FQP3P20 (Ciss 190 pF, -2.8 A)
IRF9610 (Ciss 170 pF, -1.0 A)
M2 Positive:
IRF530 (Ciss 670 pF, 10 A, Gfs 5.1 S)
IRF620 (Ciss 260 pF, 3.3 A, Gfs 1.5 S)
IRF610 (Ciss 140 pF, 2.1 A, Gfs 0.8 S)
---
M1 Negative:
FQP3N30 (Ciss 175 pF, 3.2 A)
IRF610 (Ciss 140 pF, 2.1 A)
M2 Negative:
IRF9530 (Ciss 860 pF, -8.2 A, Gfs 3.7 S)
IRF9620 (Ciss 350 pF, -2.0 A, Gfs 1.0 S)
IRF9610 (Ciss 170 pF, -1.0 A, Gfs 0.9 S)
I guess DCG3 is always below 1A.
Some random comparisons:
M1 Positive:
FQP3P20 (Ciss 190 pF, -2.8 A)
IRF9610 (Ciss 170 pF, -1.0 A)
M2 Positive:
IRF530 (Ciss 670 pF, 10 A, Gfs 5.1 S)
IRF620 (Ciss 260 pF, 3.3 A, Gfs 1.5 S)
IRF610 (Ciss 140 pF, 2.1 A, Gfs 0.8 S)
---
M1 Negative:
FQP3N30 (Ciss 175 pF, 3.2 A)
IRF610 (Ciss 140 pF, 2.1 A)
M2 Negative:
IRF9530 (Ciss 860 pF, -8.2 A, Gfs 3.7 S)
IRF9620 (Ciss 350 pF, -2.0 A, Gfs 1.0 S)
IRF9610 (Ciss 170 pF, -1.0 A, Gfs 0.9 S)
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M1 can alternatively be IRF9610/IRF610 (pos/neg) when below 1A setting. It also consumes less gate to source voltage. So good enough for DCG3 UBiB PSU use. The FQP3P20 is good up to 1.77A when well hot, its 2.8A headline spec is at an optimal 25C core temperature. That is why I spec the regs at 1.5A max before considering slower but more powerful M1 types like the IRF9630/IRF630. So to stay on the conservative side.
M2 is always IRF530/IRF9530 (pos/neg) due to correct open loop gain phase margin considerations. IRF630/IRF9630 could be their only secure alternative for maintaining correct stability margins in these circuits. Theoretically so because I haven't tested them on an actual UBiB PCB as M2.
M2 is always IRF530/IRF9530 (pos/neg) due to correct open loop gain phase margin considerations. IRF630/IRF9630 could be their only secure alternative for maintaining correct stability margins in these circuits. Theoretically so because I haven't tested them on an actual UBiB PCB as M2.
See you at the DCG3 thread then with a pre-amp build made in Peter to show
I will.
You know. This is how we call our city in short.
One last question.
Is it a bad thing to mix IRF5** and IRF6** series?
M2 Positive Board:
IRF530 (Ciss 670 pF, 10 A, Gfs 5.1 S)
IRF630 (Ciss 800 pF, 5.7 A, Gfs 3.8 S)
M2 Negative Board:
IRF9530 (Ciss 860 pF, -8.2 A, Gfs 3.7 S)
IRF9630 (Ciss 700 pF, -4.0 A, Gfs 2.8 S)
IRF530 seems like a beter at Ciss and IRF9630 seems beter overall (for DCG3).
So can M2 Pos IRF530, M2 Neg IRF9630 be used?
P.S. For correct current setting of dual UBiBs as coming from the DCG3 thread, remember:
"Rule of thumb for knowing you always got 100mA reserve, massaging the particular shunt regs to good effect in all DCG3 uses, is: Negative rail R1 setting = DCG3 bias level +100mA. Positive rail R1 setting = 2xDCG3 bias level + 100mA. Sinks size must be adequate. The UBiB's MOSFETS are tough but for robust reliability better not have more than 60C on their sinks in the long run. With so much high idling circuitry in a box, good ventilation is a must too."
"Rule of thumb for knowing you always got 100mA reserve, massaging the particular shunt regs to good effect in all DCG3 uses, is: Negative rail R1 setting = DCG3 bias level +100mA. Positive rail R1 setting = 2xDCG3 bias level + 100mA. Sinks size must be adequate. The UBiB's MOSFETS are tough but for robust reliability better not have more than 60C on their sinks in the long run. With so much high idling circuitry in a box, good ventilation is a must too."