Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  
previous: Trace - Voodoo Amps [QUOTE]Hello, I was wondering if so... -- 4/13/2004 11:56 AM View Thread

Re: Cap blew up, help?!

4/14/2004 2:26 AM
Wild Bill
Re: Cap blew up, help?!
Cathode bias is just a different method of making the grid negative with respect to cathode. The actual bias voltage will be about the same in both cases, 'cuz that's what the tube needs. The method involved will change the tone of course due to other factors but the grid bias voltage necessary to set the current is the same.  
So if you'd expect those tubes to have -45 or more volts of fixed bias why would you expect to see less than -25 volts across the cathode resistor? That's why it blew up!  
If you have to sub a different cap you can screw around with the microfarads but the voltage rating is just that - the working voltage rating. Any less and you're living on borrowed time...  
---Wild Bill

Greg Simon Thanks Wild Bill. Your explanation ... -- 4/14/2004 8:10 PM