Talk to me about Variac

Dr.Mavashi

neonderthalotonalogist
Inspired by the Randy RIP thread(did he/did not). Never could understand what does that thing do? From what I understand EVH used it, what album? Any other metal greats?
 
Re: Talk to me about Variac

a variac used like EVH -
plug amp head into the variac, variac chord into the wall
The variac regulates the volutage from the wall into the amp head. An old marshall wants to see 110 volts in the US. Now most outlets put out around 120 volts. It's not a big deal to have that +10 difference.
Eddie in fact lowered the variac to about 90 volts. It caused the hazzy, fuzziness or "brown" tone. If he hadnt used it, it would just have sounded like a dimed superlead. It basically caused that little bit extra - case in point the intro to aint talking about love.
To me the variac caused the amp to sag, or brown. Some modern amps have a sag component - mesa boogies in particular - that lowers the voltage.
Variacs are not dangerous to amp head as long as they are lowered to about 90 volts and not above 120 volts. EVH said he raised his to 140 volts which would only cause a brown smoke, not tone. Your amp would basically blow up.
Now the reason I said no to randy using one is because he just didnt. his tone doesnt sag like evh's. Eddie used a variac on most of his stuff during the DLR years.
 
Re: Talk to me about Variac

I think the main reason anyone would use a variac would be so you can bias your tubes super hot without them redplateing. By lowering the ACV to the PT.This would lower your B+ /Plate voltage enabling you to bias HOT! IMO this buying trouble wholesale. Variac's belong on a techs bench...Not as a tone tool.
 
Re: Talk to me about Variac

Oh, I get it .... sort of... You bias you power amp section tubes to the point of melting but so that they don't leak throug tolex you drop the voltage on the front end with variac, that way you get the classic power amp break up(that Laney BTW is trying to bring back with the Lionheart) with out everything cranked up and tubes making it through the night. Right ?
 
Re: Talk to me about Variac

Using a Variac is not such a good idea...it's hard on parts of the amp and it will make the tube life span drop like a rock. With all the tools we as guitar players have today (dozens of different master volumes, attenuators, amazing boost pedals, killer overdrive and distortion pedals and amazing selections of amps in the sub 20 watt range) there is no need to use things like a Variac anymore...
 
Re: Talk to me about Variac

EVH was supposed to have constant amp problems . . . . I'm guessing due to the variac usage . . .
 
Re: Talk to me about Variac

I dont think using a variac is the problem. Maybe running it at 90 volts could be but if used to control voltage out of the wall its safe. Set it to 110 volts, plug in a superlead and it'll sound as its supposed to. Diming an amp and playing it all night like eddie did will wear tubes out at a quick rate no matter what.
 
Re: Talk to me about Variac

I dont think using a variac is the problem. Maybe running it at 90 volts could be but if used to control voltage out of the wall its safe. Set it to 110 volts, plug in a superlead and it'll sound as its supposed to. Diming an amp and playing it all night like eddie did will wear tubes out at a quick rate no matter what.

I agree. EVH ran his amp full-on, and that's going to wear out lots of stuff. Amps are built to handle that kind of thing for short periods of time, but just imagine if you drove your Honda Civic at 120 mph for six hours every day. Sure, it can go that fast, but it's not going to last very long.

Of course, EVH had the luxury of having amp techs on hand at all times. You get those when you're a guitar god.

- Keith
 
Re: Talk to me about Variac

Changing the voltage going into an amp WILL cause problems and it WILL wear out tubes MUCH faster than simply turning an amp all the way up and playing it all night...
 
Re: Talk to me about Variac

I've got a variac that I'm planning on using for amp tech work. That said I tried it with my Marshall, it made me apprehensive, but did what is being described. Fizzy Fuzzy high end, softer bass, and lower dB.

Luke
 
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