I want to buy a variac, what do I need?

[dragonbat13]

I would like to buy a variac. Preferably under 250 dollars. What specs as far as amprage, voltage or features do I need. I have already decieded that I want one that has a meter.

Thanks

[908ssp]

I have 10 amp one with meter and run 50 watt Marshall on it pegged and never see over 2.5 amps drawn. So I would say buy at least a 5 amp Variac. That really is all you should need information wise. Obviously you buy one that suits your native voltage supply.

[David Root]

I bought a 1KVA unit with meter for $80, Chinese of course. The coil itself is well made, but they skimped on the ancillaries. I had to replace the on-off switch, it went intermittent, and the machine screw attachment of the switch/meter/fuse housing to the coil frame is pretty cheesy and sure to fail eventually. Would have to drill out and re-tap the coil frame mounting holes and replace the bolts with 6-32 size.

However, it now works reliably.

Notice that these things come with a two pin AC plug and are not double insulated. Therefore they really need to be isolated from the wall AC supply by an isolating transformer. Ted Weber makes a nice one, the Safe Buss Isolator, all nicely boxed up, with a three amp fuse and three outlets, for $125, NOT Chinese made! He also has a 1KVA variac that looks like mine for$50!

So that's $175, well within your budget, completely safe, and should handle most amps. I wouldn't crank an SVT on it though!

[pickupcentral]

Check yours with a voltmeter. I bought a chinese variac and the 120 volt setting is actually putting out 132vac.

-Phil

[hot_tube_tone]

I bought one of these a few years ago, and it has worked great.

Variac

[Sonny ReVerb]

This is similar to the one I have:

[IMG:150:128]http://img504.imageshack.us/img504/7391/variac01sr4.th.jpg[/img]

It's an old General Radio model. Mine is actually the triple metered version. I use it for first power-up of a new amp. Haven't used it to run an amp at a set voltage, but it shouldn't have any problem doing that. It's rated for 10 amps. They show up on the 'Bay pretty regularly, but they run closer to $300. I found mine at a University auction for quite a bit less.

[skyboltone]

I use a commercial dimmer. This is a true auto-transformer with a variable tap. It's rather heavy and big but handles 20 amps. I've gotten them off demolition jobs and sold several on Ebay for $20 or so. The Chinese $50 actually looks handy as heck. I like it.

[David Root]

Pickupcentral, yes I have a spare DMM on the Variac output all the time I use it, so I don't even look at the meter on the variac itself. I have to, because my shop's wall AC varies from 118 to 126 VAC all the time, seldom staying put for much more than 15 minutes.

[darrell]

I bought one of these a few years ago, and it has worked great.

Variac

I have one as well but donot trust the meter or the knob on the top there inaccurate as all get out.. It is strong enough to run 10 amps or more on depinding on your main fuse size..
I dont use it on my amp anymore but I do use it in the garage for power tools that dont have a varible speed to them..

Darrell