So I changed power tubes without biasing

[Torniojaws]

Whatcha gonna do, with just a digital multimeter available

Mostly I just checked that the filaments aren't competing with the sun, and that the sound is what it should (not too hot). For safety, I trimmed the bias pot just a tad beyond minimum.



Anyone else living on the edge?

 

[drew_drummer]

You'll just wear the tubes a bit harder or get a shitty sound if it's too cold - if you don't want to take it to a tech, then my advice is to keep a constant look on the power tubes for the next few weeks or so, just to make sure they don't purple out and explode in yer face!

 

[TheWinterSnow]

Mostly I just checked that the filaments aren't competing with the sun, and that the sound is what it should (not too hot). For safety, I trimmed the bias pot just a tad beyond minimum.

You don't bias the filaments, their power remains fixed and constant. Keeping things cool is always smart. My damn probe broke and I have yet to fix it or buy a new one. Started getting worried that my 5150's power tubes where getting old when my band started playing shows again. I just turned the bias knob all the way back to down (stock setting) just to be safe.

You'll just wear the tubes a bit harder or get a shitty sound if it's too cold - if you don't want to take it to a tech, then my advice is to keep a constant look on the power tubes for the next few weeks or so, just to make sure they don't purple out and explode in yer face!

Not quite how it works when it comes to biasing, unless you would be talking about lowering the heater filament voltages in which you would be right. Then again if he was adjusting the bias trim pot, he wasn't doing anything to the filaments, and biasing tubes colder will always increase their operating life.

 

[Torniojaws]

Maybe it's a wrong term I used By filament, I was going to refer to the thin(ish) wire near the top of the tubes. 5150 (it's quite cold bias at stock) is exactly what came to my mind and I decided to leave the bias trimmer to near minimum. Should be fine until I can get a 5W 1 Ohm resistor and some extra wire to measure it properly