Thanks. Separating channels is dropped down.
I guess there is no need for remote sensing when the regulator is built on the PCB as the amp?
I guess there is no need for remote sensing when the regulator is built on the PCB as the amp?
YMMV. Depends on how close to the receiving nodes. Just make a working one and you can easily experiment for location, sensing etc.
First I'm going to build the regulator and amp on a tube vero board. After I'll see that everything will work fine, I'll design a PCB. Remote sensing looks like a good idea in any case.
Hello Salas,
I've done my first HV regulator and now is on my new cdp.
A lot of work but now I'm very happy.
In the future I need only to upgrade some parts like caps, i/v resistors.
The noise level is really low with my 95db speakers.
I've attacched some pictures.
Now I'm testing a new one becouse I'd like to make your 12B4 preamp.
But I've some problems: your 400V to 330V version on my bench wan't work, all the components are ok but on the 9240 I've about 100mA instead od 50mA and on the output only 4V on 30mA charge and no one component is hot, only a bit the 9240.
Any suggestion? I'm sure I've made a mistake!!
Thanks a lot.
Ciao
Guglielmo
I've done my first HV regulator and now is on my new cdp.
A lot of work but now I'm very happy.
In the future I need only to upgrade some parts like caps, i/v resistors.
The noise level is really low with my 95db speakers.
I've attacched some pictures.
Now I'm testing a new one becouse I'd like to make your 12B4 preamp.
But I've some problems: your 400V to 330V version on my bench wan't work, all the components are ok but on the 9240 I've about 100mA instead od 50mA and on the output only 4V on 30mA charge and no one component is hot, only a bit the 9240.
Any suggestion? I'm sure I've made a mistake!!
Thanks a lot.
Ciao
Guglielmo
Attachments
Ah, this is a nice build. Did you compare it with some previous reg, or is it a total build? What driver transistor you use for the higher than 300V version?
Before I used a tubereg with ECL86, It was more noisy.
Now I've made some more modifications like cascode CCS and led on the catode of the 6C45.
On the reg that don't work I'm using a KSP94 that is the same of MSPA94,
in the first one (low voltage )I've used MPSA92.
Ciao
Guglielmo
Now I've made some more modifications like cascode CCS and led on the catode of the 6C45.
On the reg that don't work I'm using a KSP94 that is the same of MSPA94,
in the first one (low voltage )I've used MPSA92.
Ciao
Guglielmo
I am afraid of difficulties with heat or Ib currents in the Vref. Do you have a 2SK170 in hand?
So it will be easy to check the 300+ reg in Simpler Simplistic style? Like this one? Instead of troubleshooting while still on bench.
It looks like working great in the simulator, although all the builds are under 300V up to now. Use your driver BJT where I had another in the sim library. If it still does not make it, I would try a 150V Zener across the PMOS, and 30VZ across the JFET.
It looks like working great in the simulator, although all the builds are under 300V up to now. Use your driver BJT where I had another in the sim library. If it still does not make it, I would try a 150V Zener across the PMOS, and 30VZ across the JFET.
Attachments
I guess it will be more productive to go new than troubleshooting the other one. Make sure to start the trimmer around 180R so not to stress it. Good luck. You will be the first breaking 300+ with the SSHV if you make it. Vgeorge had made the 12B4 with 280V B+ and resistor load, he is very pleased BTW. http://www.diyaudio.com/forums/tubes-valves/137771-12b4-preamp-11.html#post2022181
I'm waiting for components and I plan to use in that configuration, one regulator for each channel
Hello Salas,
I'm starting to test the new circuit, post 891, but the Css works but shunt is like open circuit, no regulation.
My 2sk170 is 8mA.
Trimming R8 from max to 0 I've no voltage variation on R4 that have about the same voltage of the output, or 0,5v less (I've not made a specific measure) may be the voltage drop on Q2.
Tomorro I'll check all the connections another time but it works in a strange way.
What do you think about.
Which psu regulation do you use in your 12b4 preamp?
Ciao
good night
Guglielmo
I'm starting to test the new circuit, post 891, but the Css works but shunt is like open circuit, no regulation.
My 2sk170 is 8mA.
Trimming R8 from max to 0 I've no voltage variation on R4 that have about the same voltage of the output, or 0,5v less (I've not made a specific measure) may be the voltage drop on Q2.
Tomorro I'll check all the connections another time but it works in a strange way.
What do you think about.
Which psu regulation do you use in your 12b4 preamp?
Ciao
good night
Guglielmo
Hi guglielmope .
why work strange?
You can measure voltage at the location is not?
I have not tried to run on 350v input voltage. with 320v and out put 260v, 100mA total, My pre use 80mA, I have tried a lot and it is stable, sound is good!
I runt it many times on day, 12h, and more, Now I still run good,
You try to replace trimmer 220R by trimmer 1k ???.
How many mA do you need for your Pre 12B4A???
quanghao
why work strange?
You can measure voltage at the location is not?
I have not tried to run on 350v input voltage. with 320v and out put 260v, 100mA total, My pre use 80mA, I have tried a lot and it is stable, sound is good!
I runt it many times on day, 12h, and more, Now I still run good,
You try to replace trimmer 220R by trimmer 1k ???.
How many mA do you need for your Pre 12B4A???
quanghao
First time for that one with the jfet for over 300V out, so we will have to debug it. Lets see, what do you mean by open circuit? What voltage at the output? Vin-Vbe=Vout you mean? Check connections, but also see if the 2sk170 is alive too. If dead, put a new one, but clamp it with a 30V zener. Also is the trimmer OK, and is the value as recommended? Be sure it resides between source and 220k and not between gate and 220k. The 12B4 got a resistor load again to drop gain, because the amp got less feedback mod and the gain was too much so its under 300V too.
The 2sk170 is ok!
Load:10K
Vin:382,5V
Vout:380,7V
Vr4:380,1V
VbMpsa94=379,4V
Vg Irf840=0,01V
Ciao
Guglielmo
With 6,6k of load I've about 48ma output (about 300V), the CCS works ok.
Load:10K
Vin:382,5V
Vout:380,7V
Vr4:380,1V
VbMpsa94=379,4V
Vg Irf840=0,01V
Ciao
Guglielmo
With 6,6k of load I've about 48ma output (about 300V), the CCS works ok.