You need only one bipolar power supply. There are regulators in the board for each section.
Today I heard first sound from this amp. Good sound although massive hum if both channels are plugged. So it seems I have a groud loop and should modify my grounding scheme. But anyway, there is sound 
Btw, which regulators you mean except the TL431s, which are for the gates, I think?
Btw, which regulators you mean except the TL431s, which are for the gates, I think?
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Today I heard first sound from this amp. Good sound although massive hum if both channels are plugged. So it seems I have a groud loop and should modify my grounding scheme. But anyway, there is sound
Btw, which regulators you mean except the TL431s, which are for the gates, I think?
The output stage is also regulated. the mosfets act as pass devices for the voltage references. it is explained in the various articles.
Today I heard first sound from this amp. Good sound although massive hum if both channels are plugged.
So it seems I have a groud loop and should modify my grounding scheme. But anyway, there is sound
Btw, which regulators you mean except the TL431s, which are for the gates, I think?
On the first page i find useful information about Diy Sony Vfet circuit : front end , output stage and all voltage regulators.
http://www.diyaudio.com/forums/pass-labs/302380-sony-vfet-illustrated-build-guide.html
Have a nice day
Today I heard first sound from this amp. Good sound although massive hum if both channels are plugged. So it seems I have a groud loop and should modify my grounding scheme. But anyway, there is sound
Btw, which regulators you mean except the TL431s, which are for the gates, I think?
Post detailed pics showing your input connections, PSU and general circuit layout. I'm sure we can work this out.
have my amp in another space yet and cant measure when starting cold, but gnd to T18 is frontend offset and 50mV when warmed up is quite good. Check your output offset, get it less than 50mV (when i last measured mine, it was below 10mV) and enjoy.
BTW, I am using 2sj313/2sk2013 instead of the FPQ3N/FQP3P.
The Bias Voltage of the 2sj313/2sk2013 rises slowly from 1.3Volt to 1.5 Volt as described in Nelsons DIY Sony VFet guide.
In the end it settles at approx 50mV DC Offset at T18.
Thanks Soundhappy, got it.On the first page i find useful information about Diy Sony Vfet circuit : front end , output stage and all voltage regulators.
http://www.diyaudio.com/forums/pass-labs/302380-sony-vfet-illustrated-build-guide.html
Have a nice day
Cheers
Ernst
Hi Rodeo, thank you. I'll do, if I can't find the right way. Hopefully tomorrow I know more [emoji2]
Thanks for congrats Soundhappy. For sure, I sound happy now, too.
Never had such a lot of work with an amp, and frustration in between.
Btw, has anybody an idea about the the number of V-Fet amps which are ready for being listened?
This amp runs pretty cool, almost surprisingly cool (green class a amp :-D by consuming at about 110 W). So it takes a lot of time to reach temperature equilibrium for final adjustments in the 4U chassis.
Looking forward to comparing it to my dear friend Jogi's F5....
Cheers
Ernst
Never had such a lot of work with an amp, and frustration in between.
Btw, has anybody an idea about the the number of V-Fet amps which are ready for being listened?
This amp runs pretty cool, almost surprisingly cool (green class a amp :-D by consuming at about 110 W). So it takes a lot of time to reach temperature equilibrium for final adjustments in the 4U chassis.
Looking forward to comparing it to my dear friend Jogi's F5....
Cheers
Ernst
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First 2 channels up and running!
Only changes I did were the resistors for the JFETs and also I was close to having to swp the 5k trimmers for 10k, but then I chose other VFETs instead.
I found bias easy to adjust.
Removed my DartZeel clone from one of my many Consonance Calaf enclosures and the Italian brackets almost fit in it.
I managed to fasten 3 screws without drilling more holes
No heat problems during 3h of listening.
I have two 160VA noratel trafos and 200pcs of BC 1000uF caps in the enclosure
Well enough.
Sound is...interesting.
It is good in many ways.
Very detailed. Bass is surprisingly good with my 4ohm line arrays.
Sound is not soft or very warm, but neither is it fatiguing.
It is a bit close to the DartZeel NHB-108 and maybe has some resemblance to my McIntosh MC275.
I have like 0 noise, but some hum. I have wired the speaker - to powersupply ground and not amplifier PCB, so I will do some experimenting with this soon.
Will need to do 100h more listening before I say anything more
The measurement I have attached is actually at 3.5ohm 2W.
With the even harmonics included (I usually do not measure those) I get 0.02%.
This is good and I can make some proper measurements later.
By the way I remember somebody asked about the 0.1ohm resistors.
Should I just skip them for the other 4 channels?
I adjust bias when running on a lab PSU so it is very easy to read bias on the meters there.
Of course the 0.1ohm resistor makes it easier to do in the field. Unless PSU is CRC.
THANK YOU NELSON AND ALL VERY MUCH FOR THIS WONDERFUL PROJECT!
Only changes I did were the resistors for the JFETs and also I was close to having to swp the 5k trimmers for 10k, but then I chose other VFETs instead.
I found bias easy to adjust.
Removed my DartZeel clone from one of my many Consonance Calaf enclosures and the Italian brackets almost fit in it.
I managed to fasten 3 screws without drilling more holes
No heat problems during 3h of listening.
I have two 160VA noratel trafos and 200pcs of BC 1000uF caps in the enclosure
Well enough.
Sound is...interesting.
It is good in many ways.
Very detailed. Bass is surprisingly good with my 4ohm line arrays.
Sound is not soft or very warm, but neither is it fatiguing.
It is a bit close to the DartZeel NHB-108 and maybe has some resemblance to my McIntosh MC275.
I have like 0 noise, but some hum. I have wired the speaker - to powersupply ground and not amplifier PCB, so I will do some experimenting with this soon.
Will need to do 100h more listening before I say anything more
The measurement I have attached is actually at 3.5ohm 2W.
With the even harmonics included (I usually do not measure those) I get 0.02%.
This is good and I can make some proper measurements later.
By the way I remember somebody asked about the 0.1ohm resistors.
Should I just skip them for the other 4 channels?
I adjust bias when running on a lab PSU so it is very easy to read bias on the meters there.
Of course the 0.1ohm resistor makes it easier to do in the field. Unless PSU is CRC.
THANK YOU NELSON AND ALL VERY MUCH FOR THIS WONDERFUL PROJECT!
Attachments
Soundhappy if you mean internally then Thank You!
If externally then thanks to the Chinese who make nice enclosures. (I have 3 of them, all in different colors)
BK it is not a separate software.
It is what is on the Rohde und Schwarz UPL66...not sure if it has a name
BTW I put F1.6A fuses on the +/- wires going to the amp boards.
This should protect it a bit, but might also decrease fidelity.
I am looking for ideas howto do this in the final amp.
If externally then thanks to the Chinese who make nice enclosures. (I have 3 of them, all in different colors)
BK it is not a separate software.
It is what is on the Rohde und Schwarz UPL66...not sure if it has a name
BTW I put F1.6A fuses on the +/- wires going to the amp boards.
This should protect it a bit, but might also decrease fidelity.
I am looking for ideas howto do this in the final amp.