Anyone using a Variac with their Marshall Head?

Rotorcraft230

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I have collected a few Superior PowerStats over the years and they are VERY robust. They started making then in the late 40 and still make them today (not by superior though). You can wire them easily to max out at wall voltage vs the 130vac(that’s too high). Here are some of mine. If you watch they can be had for about 50-75 bucks. AB86C967-568A-49A3-A660-8609E79CB27A.jpeg
 

Rotorcraft230

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Another thing I could add it may be helpful or not. I monitor my wall voltage via a gauge that sits on my desk, it’s a large meter so it’s easy to see. Here is what I have experienced.

My voltage is 122vac and it’s very steady. It drops 2vac when my ac kicks on then recovers back to the 122, it’s only a second or two though. Like it’s been said before, a Variac won’t regulate but will fluctuate with the wall voltage. Hard to say what venues power is doing.
 

flyinguitars

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Another thing I could add it may be helpful or not. I monitor my wall voltage via a gauge that sits on my desk, it’s a large meter so it’s easy to see. Here is what I have experienced.

My voltage is 122vac and it’s very steady. It drops 2vac when my ac kicks on then recovers back to the 122, it’s only a second or two though. Like it’s been said before, a Variac won’t regulate but will fluctuate with the wall voltage. Hard to say what venues power is doing.
Thanks..yes next step is to get a conditioner/regulator. We/he are playing all kinds of different venues like old theaters, outdoor festivals using generators, arenas, and even clubs. Most places have big HVAC systems, refrigerators, etc....so we never know what's in store with power. Some of the places that we play annually have really noisy power. We always say "oh no...that's right we always have a really bad buzz here"...haha ..so it's time to invest in a good conditioner/regulator.

Btw how can you modify the variac to max out at wall voltage? That sounds like a good insurance policy.
Thanks
Mike
 

Rotorcraft230

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Here is a tag that come with the Variacs, you can choose from 120 or 140, cw or ccw 6859B29D-F3D6-49D3-A30D-1DA561AC4ABF.jpeg 9C11BDAD-E54F-4A3E-8011-94C8BA928193.jpeg
Thanks..yes next step is to get a conditioner/regulator. We/he are playing all kinds of different venues like old theaters, outdoor festivals using generators, arenas, and even clubs. Most places have big HVAC systems, refrigerators, etc....so we never know what's in store with power. Some of the places that we play annually have really noisy power. We always say "oh no...that's right we always have a really bad buzz here"...haha ..so it's time to invest in a good conditioner/regulator.

Btw how can you modify the variac to max out at wall voltage? That sounds like a good insurance policy.
Thanks
Mike
 

tonefinder

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My daily driver is a legit 1972 super lead. I run it at 90 V using a Variac that has a voltage meter on the output.

I've been chasing that sound for about 40 years it's my impression that nothing sounds like a super lead at 90 V or so. Completely changes the character of the amp under your fingers....
Sounds like you're set up for recording- would love to hear clips!
 

Rotorcraft230

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I didn't realize they made them in horizontal input. I'm guessing it is no different than a vertical input? Sure sounds like one of the greatest JCMs I've ever heard... I'm guessing that is the variac helping. The gain sounds really good and higher than I was expecting.
The vertical inputs have the pots mounted the the chassis and the horizontal inputs are mounted to the PCB, not sure when this changed happened but I’d guess 1984 ish
 

Labjr

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I have collected a few Superior PowerStats over the years and they are VERY robust. They started making then in the late 40 and still make them today (not by superior though). You can wire them easily to max out at wall voltage vs the 130vac(that’s too high). Here are some of mine. If you watch they can be had for about 50-75 bucks.

Nice collection. I'm sure there's a use but, I can't imagine wiring for CCW rotation to raise the voltage. The first instinct is to turn the knob to the left when you see smoke. 🔥

What else do I see? Ti-1200 calculator? Weller WTCPT?
 

Rotorcraft230

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Nice collection. I'm sure there's a use but, I can't imagine wiring for CCW rotation to raise the voltage. The first instinct is to turn the knob to the left when you see smoke. 🔥

What else do I see? Ti-1200 calculator? Weller WTCPT?
The cw or ccw, is a feature where you can mount the knob on either side, like if it was mounted to something you can still have proper rotation ( if that makes sense). The soldering station was a 20 dollar pawn shop find, I wouldn’t have anything else, I love it. The calculator I found in the trash. It was NIB, it’s my calculator of choice.
 

Labjr

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The cw or ccw, is a feature where you can mount the knob on either side, like if it was mounted to something you can still have proper rotation ( if that makes sense). The soldering station was a 20 dollar pawn shop find, I wouldn’t have anything else, I love it. The calculator I found in the trash. It was NIB, it’s my calculator of choice.
Now is the time to find the deals on equipment and electronics while the economy is sinking. Companies are closing their doors and selling off surplus equipment.

I recently bought a brand new Fluke 117 DMM for $50 on Facebook marketplace. The guy had more But I already had two Flukes. Great to have extra DMMs when burning in amps.

I have a small collection of soldering stations. I orginally intended to replace the Weller which is getting old and started trying everything. If i see a good deal, I grab it. I Now have Weller, Hakko, Pace and four Metcal stations. I'll sell off some of it. Metcal is the cat's ass.
 

flyinguitars

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I didn't realize they made them in horizontal input. I'm guessing it is no different than a vertical input? Sure sounds like one of the greatest JCMs I've ever heard... I'm guessing that is the variac helping. The gain sounds really good and higher than I was expecting.
Yea I have vertical and horizontal. I've had that one since 89 and it's been modded by our phila area amp guru. He had his own line of handmade boutique amps for a while and is an walking amp repair encyclopedia. That amp rips!
I had a 2205 but sold it late 90s.
 
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Rograt

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OK not a Variac but after a few years of constant complaining about the price I succumbed and bought a Waza Tube Amp Expander. I haven’t regretted it for a microsecond. It’s the only thing I would use with my JVM410HJS. You get lots of EQ variation if you want it and reverb and delay (plus another effects loop) at the very end of the chain (post power amp!) just where I like them. And then you can record via USB with built in or your own IRs. It’s brilliant. I even bought the footswitch.
 

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I use a Furman SPR 20I, and an AmpRx Brown box.
The SPR20i regulates voltage to within 1%. The P1800AR which is a good unit, regulates the power to within 5%. SPR20i is considerably more expensive than the P1800AR.
I was burning up NOS KT66 because of to much voltage. Sometimes the voltage would be 129v. I now run the volts at 110v-112v regulated. Amp is also biased at 112v. Ive now not burned up 1 KT66 in 5 years.
 

jchrisf

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Yea I have vertical and horizontal. I've had that one since 89 and it's been modded by our phila area amp guru. He had his own line of handmade boutique amps for a while and is an walking amp repair encyclopedia. That amp rips!
I had a 2205 but sold it late 90s.
Ok.. that explains why it has more perfect gain. Yeah, that is a keeper there and it looks cool too.
 

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