He was referring to this one -->
http://www.diyaudio.com/forums/power-supplies/192625-sslv1-1-builds-fairytales.html
As far as I can recall Salas gave permission to Quanghao to do those boards. Also, in the past, when someone did not want their circuits boarded by Quanghao, he respected the author's wish.
Interesting...
I use a similar C3g stage as output for a AD1865 Dac and a Lundahl 1660 SE transformer fed by a SSHV board from Quanghao. Blessed with ignorance I threw in a 20µF Ultrapath cap to the cathode, and the sound became even better. The current mosfet becomes pretty hot though, current is about 70mA with around 28 mA to the tubes and just 15V Vin - Vout.
Having no scope, I can't measure oscillation, but the whole thing seems to be rather stable and there is definitely no trace of harshness. A little noise is there when full Volume with my horn speakers, maybe comes from the birds nest it still is on the breadboard.
Maybe you can try 150-160V for anode, as the C3g seems pretty sensitive to changes of anode Voltage. With 170V/15mA it sounds a bit dry and mechanical, less current brings down the high freq a little. I settled to 160V/14mA in my setup.
Probably I try a smaller Ultrapath, I have some 4,7 Siemens MKV around, maybe they put less stress on the reg.
BTW the C3g is a wonderful tube, didn't expect that kind of sound with a Dac...
Cheers,
Juergen
Yes, for the group buys. Those on shop must be left overs. I did not give infinite time OK for using my nick name for products though. The regs are going to get new and official boards anyway. Quanghao was OK for making the regs available and helped. No problem for those older versions.
To check for oscillations without a scope, bring an AM radio near the regulator and play around with the receiver frequency, while moving the radio around (closer and further) the regulator. You should be able to pick the oscillations and by turning the regulator on/off you can see if it's the real source.
You could always tell him to take them off if you don't agree. He was quite reasonable in the past and did respect my wish of not doing anything with my stuff.
There is plan for a circuit revision and official new board, so no point. Quanghao had filled the gap back then, gave opportunity to many having the regs on PCB, that's OK.
Bring on the revision, bring on the revision! course I want to run them in an OTL and would like up to 1.3A constant, 4A surge +/-200V output.......so thats two boards.....well 4, want to do my preamp as well.......sigh.......
Forget such currents from the SSHV. Its good for up to 100-150mA. You can use it for the driver sections. You imagine the heat at such voltages and currents with 2.7A headroom?
Bugger.......I can dream.....which is what I should be now doing.....
Thanks Salas! Your assistance is fantastic and a credit to you gents who support....well...us and our endeavours, really appreciated!
Well the heat of 16 tubes a channel isn't insignificant either!
Thanks Salas! Your assistance is fantastic and a credit to you gents who support....well...us and our endeavours, really appreciated!
Well the heat of 16 tubes a channel isn't insignificant either!
Hi Juergen, thanks for joining!!
I will try lower anode voltage since it is so easy to change with the Salas reg... 😛 I will also have to go a bit bigger with the Cathode resistor (~180R).
Thanks for your experience with the Ultrapath in your C3G output stage... wanted to try that for a long time. I do have the aforementioned russian PIO and also Siemens MKV... when only they were not so big...
I am suspecting oscillations more due to the fact that the shunt Mosfet gets warm relatively quick which I didn't notice in other builds with similar load.
And yes, and not wanting to derail the thread, C3G is a wonderful tube! My first experience was with the ubiquitous Siemens Headphone amp on Jogis Roehrenbude (and it can be seen there), but I felt that it could sound better using opt's and the shunt reg.
Iko, that is a very cool hint. Will try, jut have to find a radio (in the days of digital everything 😀).
I did a point to point wiring of Salas's regulator !!!
It works and plays very well for my 6SN7 pre amp.
Saving the cost of choke and expensive filter cap. I use 57 ohms for R1 so the CCS current is 34ma approx. and fed by 360V raw DC, out at 300V for two 6SN7. The total current consumed by this pair tube approx. 16ma and I tried to tripple the supply but it's getting hot !!!! I just use the chasis cover for heat sinking so I go back to double the value only.
Salas, would you tell me the latest version that I can make further improvement ? Because the discussion is very long .... ha ha ha
Thanks Salas.
It works and plays very well for my 6SN7 pre amp.
Saving the cost of choke and expensive filter cap. I use 57 ohms for R1 so the CCS current is 34ma approx. and fed by 360V raw DC, out at 300V for two 6SN7. The total current consumed by this pair tube approx. 16ma and I tried to tripple the supply but it's getting hot !!!! I just use the chasis cover for heat sinking so I go back to double the value only.
Salas, would you tell me the latest version that I can make further improvement ? Because the discussion is very long .... ha ha ha
Thanks Salas.
Attachments
Truly unique build. The BC transistors first reg in direct to chassis dead bug wiring! Are you sure you want to dismantle that for a later update?🙂
Attachments
Thanks Salas.
Because it is p-to-p wiring, so any modification is very easy to me. But the latest version seems I need to rebuild one .... ha ha ha
Also, if I feed 360V raw DC, will it cause any problem?
Thanks Salas
Because it is p-to-p wiring, so any modification is very easy to me. But the latest version seems I need to rebuild one .... ha ha ha
Also, if I feed 360V raw DC, will it cause any problem?
Thanks Salas
