Variacs

[9astro]

Hi. Anyone know a good rule of thumb for what size/capacity variac one should use for a guitar amp?

They seem to be rated in VA, which I don't know how to correlate to wattage, amperage, or other capacities that an amp might require.

Thanks.

 

[ryanjp2c]

860 + views and not one reply : /

try here:

https://www.youtube.com/watch?v=7SIIHuEizps

 

[axeman]

The "VA" rating is simply the Volt Amp rating of the power use. It is very similar to watts but the is some phase shift in the current voltage orientation and poeer factor. VA is said to be the true power rating. This really does not concern us. So If your amp is 120 volt and has a 3 amp fuse in simple terms it would be 360VA.
As a safety factor double that number or more
(adds more capacity but changes nothing else) and you should ber ok. It is a good idea to have meterIng on your load output. Hope this helps.

 

[axeman]

The "VA" rating is simply the Volt x Amp rating of the power use. It is very similar to watts but there is some phase shift in the current voltage orientation and power factor. VA is said to be the true power rating. This really does not concern us. So If your amp is 120 volt and has a 3 amp fuse in simple terms it would be 360VA.
As a safety factor double that number or more
(adds more capacity but changes nothing else) and you should be ok. It is a good idea to have metering on your load (output).Hope this helps.
Ps. KVA just means add 1000. So 360VA = .36KVA. Sorry for earlier typos.