View Full Version : Should I be able to hold my Twin's power tubes
gadjet
03-03-2009, 08:22 PM
I can put my fingers on my Twin's power tubes for an extended period of time.... Stupid test I know but could this be a indication of a cold bias?
Blue Strat
03-03-2009, 08:27 PM
Unless you have issues with sensation in your fingers, yes. The amp is probably biased way cold.
However, a bias probe would be the correct tool for the job...not your fingers;)
jay42
03-03-2009, 10:08 PM
Something's wrong. You should have second degree burns...at least. Trying to remember...someone here tested the envelope temperature for some tubes and came up with either 250 or 280 Fahrenheit. That'll boil the water in your skin nicely.
schmidlin
03-03-2009, 10:27 PM
Wait, the obvious question should be asked: Was your amp ON at the time? (standby off, of course).
as mentioned,your tubes are not pulling enough cathode current!
gadjet
03-04-2009, 06:29 AM
Something's wrong. You should have second degree burns...at least.
as mentioned,your tubes are not pulling enough cathode current!
My thought's exactly.. The guy who bias'd it said he thought the Twin's bias should not be set as high as they spec it at.. I loved the way this amp sounded with my pedals, now it sounds horrible with them.
donnyjaguar
03-04-2009, 09:46 AM
If the amp is in standby you can hold your finger to the top of the envelopes without burning them. If its on for a time and idling, you shouldn't be able to do this.
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