Tube questions

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rcane

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New to tube gear--just got the EH 12AY7 pre. Does it need to warm up for awhile before I use it--if so how long? If I'm swapping out tubes, do I need to wait for them to cool down before swapping? Thanks for helping a tube newb.
 
usually thers a "burn in' time for about 15-20 minutes if it a brand new -unused tube. after the inital burn in......it will work fine anytime you turn on your amp and just start playing away.

i would let it cool down when pulluing the tube out, only to protect your fingers from getting burned! those things get hot! it wont hurt the tube if you pull it and its still warm, just dont pull it out when your amp is on and the thing is still glowing!

if you need more help, let us know. and remember.......tube swaping becomes adictive. once you try it ,......youll wanna get another tube and see what it sounds like, and then another, and another,........etc.....

ive gone trough so many 12ax7 tubes,....i think ive tried them all!
 
Been awhile since I messed with tubes but, yeah, I let my old bass tube head warm up for about 15 or 20 minutes. Tubes also tend to sound better with age. The cool down part is probably a good idea due to how thin the glass is. After I touch a tube with my fingers, I'll wipe it down real good with a soft cloth. I heard a long time ago that the finger prints left behind create a "hot spot" on the glass. Dunno if it's true but I've never had one go bad.....
Hope it helps man..............
 
LOL....Bryan, looks like we were typing at the same time... :D
 
Dogbreath said:
Been awhile since I messed with tubes but, yeah, I let my old bass tube head warm up for about 15 or 20 minutes. Tubes also tend to sound better with age. The cool down part is probably a good idea due to how thin the glass is. After I touch a tube with my fingers, I'll wipe it down real good with a soft cloth. I heard a long time ago that the finger prints left behind create a "hot spot" on the glass. Dunno if it's true but I've never had one go bad.....
Hope it helps man..............
any oils from your skins will eventually create a "bubble" type blister on the glass, which will eventually either crack or pop the tube. that goes for any professional grade lamp bulbs as well (like the lights you see on stage).
 
thexflamesxburn said:
any oils from your skins will eventually create a "bubble" type blister on the glass, which will eventually either crack or pop the tube. that goes for any professional grade lamp bulbs as well (like the lights you see on stage).

Well, that's certainly a potential issue for a power tube like you'd have in an amplifier. I wouldn't have thought preamp tubes got hot enough for that sort of failure. It's still probably a good precaution, though.
 
Pulling tubes when hot is a bad idea...the heater and other elements get hot and sudden jerky pulls out of their sockets can shorten or end their life. Think of spankin' a hot light bulb...I would let them cool for a minute or two to be safe. As for playing into them...again, let them warm up...a minute would be plenty. Depending on how they're biased pumping hard signals into them can flatten them and again shorten their responsiveness and life. Ideally, the tube is brought up to temperature before pumping fat signals into it.

I have no first hand knowledge of your amp but tubes not run in starved plate mode in general need just a little more TLC...let them warm a minute or so before use and let them cool a minute or so before yankin' them out.

Anyone ever considered a 4CX10000 for a mic pre? No?...just wondering :D
 
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