So, heat...

[mmrxcsr01]

5e3 build, a little bigger cab (5e5 pro), and after the build, the burn in. Chassis (Weber chrome, from years ago), after running 4 hours, very nearly too hot to hold your fingertips on for more than a few moments. Thoughts?

 

[ked]

Unless the power tubes are red plating you probably don't have a problem. With the tubes hanging upside down, all that heat move upward and the chassis get very warm. A fan in the back will help.

 

[pdf64]

If the power transformer puts out a little too much voltage then the circuits have to dissipate more power (power being related to voltage squared) and things get hotter.
What's the VB+across the reservoir cap (eg 360Vdc), and the heater voltage (eg 6.3Vac)?
Power tube cathode resistor value and static voltage?

 

[mmrxcsr01]

B+ is at 392/361/283. Plate voltages are 378 and 392 (with old, odd 6v6's ) ; cathode resistor (250 ohms 5 watt) drop is 18 volts. Old 5y3. Fender Deluxe Revern p/t and o/t. So around 13 watts. I know they're all a bit high, waiting on a zener diode...and I have a "bucking box" built as well. I'm ok with the voltage issue, it just seems this is SO hot to the touch...thanks for your time all.

 

[EFK]

Man, that's one heck of a plate voltage spread for a shared cathode resistor imho.

After 4 hours on any of these type of cathode biased, 100%+ idle amps (old tweeds, many valcos, old Gibson GA amps etc.), they're ALL hot as hell, primarily power tube side of the chassis and the power transformers also are usually cooking. 4 hours is a long time to run one of these uninterrupted; most people I know turn them off on breaks, or between sets etc., let them cool down a bit as they warm up super fast anyway.

 

[mmrxcsr01]

Man, that's one heck of a plate voltage spread for a shared cathode resistor imho.

After 4 hours on any of these type of cathode biased, 100%+ idle amps (old tweeds, many valcos, old Gibson GA amps etc.), they're ALL hot as hell, primarily power tube side of the chassis and the power transformers also are usually cooking. 4 hours is a long time to run one of these uninterrupted; most people I know turn them off on breaks, or between sets etc., let them cool down a bit as they warm up super fast anyway.

Thanks again for your time...again, the 6v6's are old, different brands...higher- than- they- should- be- voltages...all the tubes are just ones I use for the initial burn in of a new build. I try to suss out an issue before I take it out to gig, or let someone else use it at an open stage...thank you for your time, and input. If you're ever in the Pittsburgh area...please let me know.


Here's the amp...