First C only. But yesterday you had no B+ bcs of a broken trace? So an electronic cloud was sitting like mist hitting cobalt on glass making it great electric blue to look at?
I'll bet I am right, although I like your explanation better. Its more poetic and soothing than my inablility to execute a design😀
Need help
Salas,
I found my 26 pre-amp sound wired suddenly and the voltage on both R/L channels fluctuate quite seriously. The raw supply is stable at 172v. The LEDs are all on and I can't check the voltage reading since they keep swinging. The trimmers are working and can tune the voltage to certainly level, but jump to the extreme all in a sudden.
Regards
Albert
Salas,
I found my 26 pre-amp sound wired suddenly and the voltage on both R/L channels fluctuate quite seriously. The raw supply is stable at 172v. The LEDs are all on and I can't check the voltage reading since they keep swinging. The trimmers are working and can tune the voltage to certainly level, but jump to the extreme all in a sudden.
Regards
Albert
Last edited:
Salas,
I found my 26 pre-amp sound wired suddenly and the voltage on both R/L channels fluctuate quite seriously. The raw supply is stable at 172v. The LEDs are all on and I can't check the voltage reading since they keep swinging. The trimmers are working and can tune the voltage to certainly level, but jump to the extreme all in a sudden.
Regards
Albert
Oh....sorry, forgot to tell, mind is an old version SSHV1. Please see attached. Thanks
Attachments
Oh....sorry, forgot to tell, mind is an old version SSHV1. Please see attached. Thanks
Hi!
My be Mje 350 , it is hot, and 840 died, please change it!
Hi!
My be Mje 350 , it is hot, and 840 died, please change it!
Changing both MJE350 & IRF840, and both channels???
Changing both MJE350 & IRF840, and both channels???
check it, if MJE 350 hot, please change it and IRF840!
check it, if MJE 350 hot, please change it and IRF840!
The 840 is only 30c. I have to check the 350.
check it, if MJE 350 hot, please change it and IRF840!
I've both the 350 & 840 changed to new. Not working, still swinging.
Check BE and GS voltages to see if fets and bjts are working.
George,
Thanks and I have them checked after taking out from the board so to compare. The new and the took-out ones - 350/840 - measured the same. I don't have any chance to take number when it's on. The voltage keeps fluctuating. I have 2 boards for L/R. While I set close to 150v on one side, then the other side shifted to different extreme, either very low/ or very high voltage. One thing I don't understand is when one channel voltage drops to very low, the other board's voltage go very high, even higher then the supply voltage.
Before this happened, I had 172v from the main then split to two boards. I could easily adjust to 150v without problem.
Albert
[QUOTE=albertli;
What the value of R1?
33 R or 27R
down R1, set current CCS for all, you can get the V-out !
Not: Use current =80%, and IRF 840 = 20%.
What the value of R1?
33 R or 27R
down R1, set current CCS for all, you can get the V-out !
Not: Use current =80%, and IRF 840 = 20%.
if you want SSHV much better filter, you need to replace C2 = 1uF capacitor with larger value, such 4.7uF to 10uF/400V.
Quanghao
Quanghao
Salas,
I found my 26 pre-amp sound wired suddenly and the voltage on both R/L channels fluctuate quite seriously. The raw supply is stable at 172v. The LEDs are all on and I can't check the voltage reading since they keep swinging. The trimmers are working and can tune the voltage to certainly level, but jump to the extreme all in a sudden.
Regards
Albert
Oscillation most probably. Did you tweak something at the receiving ends?
Oscillation most probably. Did you tweak something at the receiving ends?
Salas,
I didn't touch it after it was up. It's my plan to add a telfon 0.047 to C2, but can't find it still.
Albert
What the value of R1? 56R for 40mA
33 R or 27R
down R1, set current CCS for all, you can get the V-out !
Not: Use current =80%, and IRF 840 = 20%.[/QUOTE]
Is it a benefit to run it too hot. What I need is 5mA per 26. It was running perfectly, but suddenly turn into this. I checked temperature for all fets and 2 legs, no sign over overheat. I didn't check the 170 yet.
33 R or 27R
down R1, set current CCS for all, you can get the V-out !
Not: Use current =80%, and IRF 840 = 20%.[/QUOTE]
Is it a benefit to run it too hot. What I need is 5mA per 26. It was running perfectly, but suddenly turn into this. I checked temperature for all fets and 2 legs, no sign over overheat. I didn't check the 170 yet.
You say your leds flicker?
leds light up as usual. Trimmers working, but only the voltage won't stay.
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