• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

raccomandation with valve amps

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Hi, I'm a rookie of valve, so I start reading "getting the most out of tube by Robert B.Tomer" wich I found on the sticky post, very usufull.
Since I don't understand english at 100% I would like ask somethings wich I didn't understood completly.

To make lasting more time the valves,
I mustn't turn on/off like crazy the amp,
always warm up the amp with volume to zero( for what time? few mins or 10/15 or more?),
when I turn off the amp if I have to move it I must wait until is cold,
other to know?

I have a AMC CVT2030 (hybrid amp 4 EL34 valves) and a Vincent SA-31 preamp( hybrid with 2 valve I don't found the name).

Vibration are not good for valve, right? because if it's the same with light lamp... When I rotate the knob of the preamp to select sources I feel a vibration on its chassis. should I care or not?
IT could be because I put on the preamp over the cd and radio, so it's more shaking?
An externally hosted image should be here but it was not working when we last tested it.


Other thing I have a doubt.. Is it good have the amp near the speaker( fostexFE206) like in the pic?
An externally hosted image should be here but it was not working when we last tested it.


thank you for the attention and bye
 
Valves are not as fragile as some people think. They were designed to go in miltary aircraft and on car bonets and all sorts of nasty places and they still last a long time! so in your amplifier they shoudl last for years no matter how many times you change the selector switch! They don't run as hot as lightbulbs (ok some of the VERY early ones did but nothing we use now does) so it's nothing to worry about.
 
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Joined 2004
Hello Testarossa2k,

I agree with Merlinb, valves are quite robust. Just think of all the vibration and moving about that a guitar amp has to endure - many of those use valves.

The sound quality of a valve amplifier can improve a little during the first 15 - 30 minutes after switching on, but it won't harm the valves if it's used immediately.

You are right when you say that valves are more easily damaged when hot, so they should be allowed to cool down for 30 minutes or so, before being moved.

The temperature of a hot valve depends on the amount of current going through them. Most preamp valves get warm but not too hot to touch; ouput valves such as EL34 run hot enough to burn your fingers and must have good ventillation.
 
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Hi testarossa2k,
I used to repair those under warranty. I don't know if they changed things, but the EL34's used to be directly soldered to the PCB. Not fun to replace.

As ray_moth indicated, good ventillation is very important. I agree with everything posted so far. Let me add, do not leave your gear running all the time.

-Chris
 
Let me add, do not leave your gear running all the time.
no absolutly not... I'm non so mad:D

but it won't harm the valves if it's used immediately.

ok so just tu be sure just few mins of warm up:)

Most preamp valves get warm but not too hot to touch; ouput valves such as EL34 run hot enough to burn your fingers and must have good ventillation.

yes the preamp is lukewarm but the amp is hot, infact it has some silent fan to cool down the valves, it has 30W.
 
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