Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Leevi on April 12, 2014, 04:02:32 pm
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I'm using both tube and SS rectifier like in picture A
http://el34world.com/Forum/index.php?action=dlattach;topic=14469.0;attach=32505 (http://el34world.com/Forum/index.php?action=dlattach;topic=14469.0;attach=32505)
Everything works fine with SS but when I switch to the tube rectifier the power supply
starts to crackle after a while and the rectifier tube flashes. Sometimes even the fuse has blown.
This happens randomly, sometimes it takes longer time before the problem occurs.
I have also tried with another rectifier tube (5Y3) without success.
Could some the following reasons cause this?
- The 5V filament wires are too close to high voltage secondary
- The PT is partly damaged
- I'm using the pin 7 of the rectifier tube socket for filter cap
Leevi
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- The PT is partly damaged
- I'm using the pin 7 of the rectifier tube socket for filter cap
I'd vote for these 2 causes. Especially if you're using pin 7 as a ground lug for your filter cap (now a ground is right next to 2 high voltage points where a ground never exists in normal rectifier usage).
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It's pretty clear that the PT is damaged.
I used a separate 5V filament transformer and the amp worked without problems.
Thanks for your response HotBluePlates!
/Leevi