Smashup Volatges Off 1 Side [resolved]
- Thread starter galyons
- Start date
OK, so this convinces me that your regulator board is probably working OK. Do you have more than two 4P1L's? It's possible that one may be internally shorted somehow, and dragging the output of the regulator down?
Luckily, we have a current limiter on the filament regulator board, so you won't burn it up by loading it down too hard (but the delivered voltage will drop!).
-PB
Luckily, we have a current limiter on the filament regulator board, so you won't burn it up by loading it down too hard (but the delivered voltage will drop!).
-PB
galyons
New member
Hi Paul,
I switched sockets with my original pair and the lower HV reg board voltages followed. So, yes, maybe an issue with the tube. I put in a new pair of 4P1L's, same HV & LV issues. I tried my 3rd and final pair, all voltages are pretty much "spot on", other than +Reg A and the 4P1L heaters. The 4P1L filament regulator measured:
I = 7.1V
0 = 2.8V
The rest of the measurements at the boards are:
IA 180-220V = 204V, 204V
OA 150V ± 1% = 150V, 149.4V
+reg (A side) 2.5V = 1.1V, 1.3V
IB 150V ± 1% = 150V, 149.4V
OB 45-75V = 53V, 57V
Kreg (B side) 3-5V = 4.7V, 4.9V
Breg (B side) 150V ± 1% =150V, 149.4V
+reg (B side) 150V ± 1% =150V, 149.4V
Cheers,
Geary
I switched sockets with my original pair and the lower HV reg board voltages followed. So, yes, maybe an issue with the tube. I put in a new pair of 4P1L's, same HV & LV issues. I tried my 3rd and final pair, all voltages are pretty much "spot on", other than +Reg A and the 4P1L heaters. The 4P1L filament regulator measured:
I = 7.1V
0 = 2.8V
The rest of the measurements at the boards are:
IA 180-220V = 204V, 204V
OA 150V ± 1% = 150V, 149.4V
+reg (A side) 2.5V = 1.1V, 1.3V
IB 150V ± 1% = 150V, 149.4V
OB 45-75V = 53V, 57V
Kreg (B side) 3-5V = 4.7V, 4.9V
Breg (B side) 150V ± 1% =150V, 149.4V
+reg (B side) 150V ± 1% =150V, 149.4V
Cheers,
Geary
It's possible that feeding the regulator board with mostly AC (from the disconnected capacitor) damaged the regulator. It might be a good next step to replace the L200 chip.
-PB
-PB
galyons
New member
Thanks Paul! That did it! All readings in spec, (getting 4.1V out on the filament reg board ;D), except +reg (A side) 2.5V = 1.1V, 1.3V, still low. You haven't commented on the +reg (A side) being low, so I am assuming it is OK?
I am still getting about 3-5mV of hum at the outputs. I will work on that in the next day or so!
Thanks for your help and patience.
Cheers,
Geary
I am still getting about 3-5mV of hum at the outputs. I will work on that in the next day or so!
Thanks for your help and patience.
Cheers,
Geary
If you aren't getting 2.5V out of the 431 chip on one side, you can try replacing it.
-PB
-PB
What are you getting from OB on each board?
Did you cut out the HLMP diodes when installing your Smash-up?
They are in parallel, so you'd need to do them both.galyons said:
