What Variac do you trust for your high dollar amps?

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GJgo

GJgo

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Hey guys,

Thinking about picking up a Variac. My wall voltage is low 120s, and after paying attention I have some old Boogies which are very dear to me that the PT runs around 140° F after a good amount of playing. I've been running fans on them for years now, and, I was thinking I might want to use a Variac to be on the safe side. I did check with Mike B. and he didn't seem concerned beyond mentioning that my wall voltage was stout.

What units are you guys using?
 
Wall voltage seems to be creeping up in general. I’ve rarely seen mine go below 120 across a couple of locations, and like Dave above, I’ve seen mine go up to 124-126 at times.
 
Staco 3pn1010 with a voltage plug to monitor fluctuations.
 
John Suhr ordered me a Tenma Variac years ago and introduced to me the load/slave method while using the variac, he also uses one of these in his shop, good enough for John good enough for me! http://www.amptone.com/tenmavariac.htm
 
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Thanks guys, lots of good options. I definitely didn't want to go for some Chinese version. My goal here would be to turn the voltage down to where the PT is more like 120°.

So for the guys with recommendations- let's say for example you had a Mark IIC+ Coliseum and you want to keep it safe. What are the pros & cons of a variac like the Staco vs. something like the Brown Box? With an amp like this money is not an issue, more important to do it right.
 
I personally like a variac because I can set it to an exact number depending on the time of day since my wall voltage swings between 112- and 123. I can also set it to the 140 setting when it's super low to get voltages around to 117-120. The downsides are no lcd readout and your buying used off eBay.
 
GJgo said:
Staco vs. something like the Brown Box?
Click to expand...

Not sure what's going on inside the Brown Box but based on its size it's not using a high quality variable transformer.
If money is no object then the Staco is the one you want.

At one of my jobs we had the same one in the lab for over 20 years and it was used almost daily - and not treated with kid gloves.
 
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I use this $60 chinese variac from Amazon with my sound city. The little LCD voltage display plugged in is also a $5-$10 chinese display from Amazon.

The variac itself feels very substantial (and heavy! - big ole torroidal transformer inside) and works great, and the knob itself is accurate to around + or - one volt

using the LCD display let’s me dial it in to the exact voltage i desire

i personally feel the Brown Box is insanely overpriced for what it is, but I can understand the sentiment of getting it because it is USA made (at least I assume/hope it is considering the price!)


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Just need to handle double the rated VA rating of the amplifier and dissipate the heat for prolonged use, that’s it. Transformers are super simple and you’re not conditioning the power just simply stepping it up or down. I use the same red Chinese 5A one as posted above on my bench for troubleshooting, if I was wanting to use one for playing then I’d get something a bit beefier to dissipate the heat better for longevity. Something in the 10A range.
 
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Nothing to shy away from with Made in China for this type of gear.
The majority of the high dollar electronics test equipment used in all
sorts of industries all over the world is MIC.
 
glpg80 said:
Transformers are super simple.
Click to expand...

Yup. Steel, iron, copper, lacquer, and wire insulation. But the quality of each material is critically important.
First way to reduce the manufactured cost of one is to use a cheaper grade iron - since iron is the bulk of the thing.

Cheaper iron = easier saturation = distortion/mud starts creeping in

This is one of those items where you really get what you pay for.
Buy Chinese at a premium price and you'll get a freaking tank.
 
glpg80 said:
Just need to handle double the rated VA rating of the amplifier and dissipate the heat for prolonged use, that’s it. Transformers are super simple and you’re not conditioning the power just simply stepping it up or down. I use the same red Chinese 5A one as posted above on my bench for troubleshooting, if I was wanting to use one for playing then I’d get something a bit beefier to dissipate the heat better for longevity. Something in the 10A range.
Click to expand...
The one I have is 10 amp....at least that’s what it was advertised as being haha. It doesn’t really run hot from my experience. Either way, it scratches that variac itch perfectly :)
 
Subbed, debating getting a brown box rack to go with my UPS - my wall voltage can fluctuate wildly but generally stays around 126-127.
 
Chubbs said:
I personally like a variac because I can set it to an exact number depending on the time of day since my wall voltage swings between 112- and 123. I can also set it to the 140 setting when it's super low to get voltages around to 117-120. The downsides are no lcd readout and your buying used off eBay.
Click to expand...
Chubbs, get one of these little voltage displays - it will allow you to dial in your variac to the *exact* voltage you want

https://www.amazon.com/gp/aw/d/B00PBW5A4I/ref=ya_aw_od_pi?ie=UTF8&psc=1
 
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