What rating of Variac for Hi-Fi use?

[walpurgis]

I've got a 2 amp rated Variac knocking about. Would that run an amplifier safely? The power consumption quoted on amps is normally specified in watts, so I'm not sure how to equate that. I guess I can find the conversion somewhere, but does anyone here know?

[struth]

www.rapidtables.com/convert/electric/Amp_to_Watt.htm

[struth]

should be ok i'd think geoff as long as it is not a huge amp. i have 160 watt one that works

[walpurgis]

Doesn't mean much to me. What is power factor for a start?

I found another online calculator actually. The results say that 2 amps will match a 500 watt requirement approximately (240V a/c). Hope that's right.

[walpurgis]

should be ok i'd think geoff as long as it is not a huge amp. i have 160 watt one that works

Right. I'm just going to plug my Krell Evolution 600 monoblocks into it. :D

[struth]

***BANG***:eyebrows:

[struth]

Here's mine

http://tapatalk.imageshack.com/v2/15/01/17/a0cfc45c5e2247dcf9c2f760aae184e5.jpghttp://tapatalk.imageshack.com/v2/15/01/17/94203882c54978195441aa08b5617b6a.jpg

[walpurgis]

***BANG***:eyebrows:

I just had a look online. The Krells use 7800 watts max. Quite a bit really. :)



I just wanted to see if the Variac would be OK with a 4 watt per channel valve amp. I reckon it'll be OK.

[walpurgis]

Here's mine

http://tapatalk.imageshack.com/v2/15/01/17/a0cfc45c5e2247dcf9c2f760aae184e5.jpghttp://tapatalk.imageshack.com/v2/15/01/17/94203882c54978195441aa08b5617b6a.jpg

That's a good idea, building a meter in. I may do that myself, one for volts and one for amps.

[CageyH]

Don't forget to account for the electrical efficiency, and start up currents etc.

[NRG]

I presume this is being done to lower the mains voltage, another way is to use a bucking tx: http://sound.westhost.com/articles/buck-xfmr.htm See fig 4. I use one for my KD990 TT as its rated for 220v and our mains hits 250v+ on a regular basis.....

[Ali Tait]

Power(watts) = Amps times volts, so 2 Amps will give you 480 watts - 2 times 240v(mains voltage).

[struth]

I just had a look online. The Krells use 7800 watts max. Quite a bit really. :)



I just wanted to see if the Variac would be OK with a 4 watt per channel valve amp. I reckon it'll be OK.

thats over 30 amps. sounds excessive.

[awkwardbydesign]

I have a pair of 2 amp variacs that I used to use for my Ming Da 18w SET monoblocks, which are Class A, so no sudden current draw. One variac would feed both amps quite happily, though. And 240v x 2amps = 480VA. VA is roughly equivalent to watts. In the end I made a couple of bucking transformers for them.
Edit; I should have read ALL the posts before I posted.