2. amps-preamps
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Variac Variable Transformer

I have a number of tube amps and tube preamps. Many are stored for a long time. Quicksilver recommends I hook up a Variac Transformer to the amps and bring up the voltage slowly and let it stay at 120 volts for ten minutes. Same process for tube preamps. I was wondering if other Audiogon members do this? I'm thinking solid state amps and preamps would be included as well...
exocet954
jritota's avatar
jritota
13 posts
 
GS5556 does you procedure include solid state power amp that has been sitting unplugged for 2 1/2 years? Thank you for your contribution to this forum. Joe
jritota's avatar
jritota
13 posts
 
GS5556 I'm referring to my old Hafler XL280 that has been sitting for all that time. I'm a little worried about throwing all that current, at start up cold, into the PS caps. So I thought if I would just ramp it up in 10 20 vac increments with my 7amp variac for a period of several hours would be prudent. Any thoughts?

atmasphere's avatar
atmasphere
11,760 posts
 
This has nothing to do with tubes. It has everything to do with older electrolytic capacitors.

You don't need a variac! All you need is a light bulb (60 watt will do fine) to put in series with the amp or preamp. Pull the tubes out if the unit is not solid state. Turn it on with the lamp in series with the AC line. If the filter caps are having a problem the bulb will light up. As the caps 'form up', the lamp will dim out to nothing (unless you have a solid stage unit, in which case it will remain dimly lit).

This will prevent serious currents from damaging the caps. If the bulb stays lit, you have a capacitor or capacitors to replace.
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