Two variacs

[novosibir]

Besides not doing this, it will be interesting to hear your solution.

None
Tune the entire organism of the amp harmoniously, then it works reliably.
A variac destroys the harmony - sooner or later - similar to how a cancerous tumor destroys a person.

 

[harddriver]

I wouldn't try this to not risk a smoked OT in my amp.
A variac is a transformer and a transformer not only transforms voltages, but also impedances.
If you have the variac half way down, then half the voltage & half the current goes to the cab, means a quarter of the power the amp puts out.
But your cab's impedance (of 16 ohms) then also is transformed to the amp what means, that the amp is seeing four times the cab's impedance, 64 ohms.
What might happen?
Voltage spikes up to 5 kV inside the OT what will damage the insulation between the OT's secondary & primary. Better stay away from such experiments!

Would that impedance mismatch be lessened somewhat if the variac was set to 90VAC as Chris Merren stipulated since most variac max voltage setting is 140 VAC?

 

[novosibir]

Would that impedance mismatch be lessened somewhat if the variac was set to 90VAC as Chris Merren stipulated since most variac max voltage setting is 140 VAC?

The opposite is the case. The lower the variac is set to, the bigger the mismatch.

 

[japetus]

I feel like EVH made people chase variacs..and they are just a dumb idea. Just get a good healthy amp with good tubes and a good master volume.

 

[Exo-metal]

I feel like EVH made people chase variacs..and they are just a dumb idea. Just get a good healthy amp with good tubes and a good master volume.

Wrong...it is a condition or state of the NFB that is unsolved. If you want an amp to behave as stated there are endless choices.

Its like saying there's no problem with candles, they work great in the dark. The only reason we have lightbulbs is bc of the unsolved problem that was solved. Enjoy the dark

 

[DanTravis62]

Wrong...it is a condition or state of the NFB that is unsolved. If you want an amp to behave as stated there are endless choices.

Its like saying there's no problem with candles, they work great in the dark. The only reason we have lightbulbs is bc of the unsolved problem. Enjoy the dark

I agree with the part about EVH though, his variac comments in magazines have probably destroyed more marshalls than anything in history - and also, if anyone has ever played a cranked plexi with some greenbacks, his tone is 100% there

 

[japetus]

Wrong...it is a condition or state of the NFB that is unsolved. If you want an amp to behave as stated there are endless choices.

Its like saying there's no problem with candles, they work great in the dark. The only reason we have lightbulbs is bc of the unsolved problem. Enjoy the dark

Oh, you think darkness is your ally. You merely adopted the dark; I was born in it, moulded by it. I didn't see the light until I was already a man. And by then, it was nothing to me but blinding!

 

[Exo-metal]

I agree with the part about EVH though, his variac comments in magazines have probably destroyed more marshalls than anything in history - and also, if anyone has ever played a cranked plexi with some greenbacks, his tone is 100% there

Yes and no...admit it. I agree about his variac. It does present a condition regarding the NFB. Believe me when I tell you I have played a lot of modded Marshall's and people to this very day always ask for a pot that tweaks the NFB. It has a profound effect.

 

[Devin]

TWO WEEKS

 

[japetus]

TWO WEEKS

Happy New Year, Kimg. And a better 2026

 

[DanTravis62]

Oh, you think darkness is your ally. You merely adopted the dark; I was born in it, moulded by it. I didn't see the light until I was already a man. And by then, it was nothing to me but blinding!

 

[japetus]

View attachment 427683

Hahhahahahhahaha

 

[Devin]

Happy New Year, Kimg. And a better 2026

Same to you kimg

 

[harddriver]

I agree with the part about EVH though, his variac comments in magazines have probably destroyed more marshalls than anything in history - and also, if anyone has ever played a cranked plexi with some greenbacks, his tone is 100% there

Yes and no...admit it. I agree about his variac. It does present a condition regarding the NFB. Believe me when I tell you I have played a lot of modded Marshall's and people to this very day always ask for a pot that tweaks the NFB. It has a profound effect.

I agree 100%...........but using a variac in the way Merren laid out does effect how the amp behaves and sounds in interesting ways regardless of the possible negative effects on the amp's output transformer.

While I would not try this on an actual vintage 68 plexi with original transformers, it may be worth implementation if you really want to hear the effects for yourself with you own ears instead of just opinions. For myself, I drifted away from using it but it does sound like JNEW's clip.

Was is part of the magic, who knows, if you like how JNEW's clip sounds like then maybe it's for you as long as you understand the risks.

I appreciate Larry's input, expertise and analysis, it's almost like old times on the Metro Amp Novosibir.......................

 

[DanTravis62]

I agree 100%...........but using a variac in the way Merren laid out does effect how the amp behaves and sounds in interesting ways regardless of the possible negative affects on amps output transformer.

While I would not try this on an actual vintage 68 plexi with original transformers, it may be worth implementation if you really want to hear the effects for yourself with you own ears instead of just opinions. For myself, I drifted away from using it but it does sound like JNEW's clip.

Was is part of the magic, who knows, if you like what JNEW clips sounds like then maybe it's for you as long as you understand the risks.

I appreciate Larry's analysis, it's almost like old times on the Metro Amp Novosibir.......................

The variac thing is definitely A sound, i'm just not remotely convinced it was THE sound of the shidd pants brown toan - I can actually play guitar and I've played a vintage plexi with everything on 10 before Anyone who has instinctively knows that there isn't really any secret to the amp, its the rest of the recording signal chain that really imparts the magic to that sound.

I guess with power stations, ox boxes, etc, and everything else out there, there are far better ways to skin that cat without destroying your transformers nowadays - christ, you can install a line out on a vintage marshall circuit, crank it up, put some kind of decent load on the amp, and slap IRs on, and you'll get way closer with way less danger to the amp IMO

 

[Exo-metal]

The variac thing is definitely A sound, i'm just not remotely convinced it was THE sound of the shidd pants brown toan - I can actually play guitar and I've played a vintage plexi with everything on 10 before Anyone who has instinctively knows that there isn't really any secret to the amp, its the rest of the recording signal chain that really imparts the magic to that sound.

I guess with power stations, ox boxes, etc, and everything else out there, there are far better ways to skin that cat without destroying your transformers nowadays - christ, you can install a line out on a vintage marshall circuit, crank it up, put some kind of decent load on the amp, and slap IRs on, and you'll get way closer with way less danger to the amp IMO

You're missing the point 1000% this isn't a post about evh or chasing his tone. This is ONLY about the NFB circuit. A theoretical discussion 100%

 

[DanTravis62]

You're missing the point 1000% this isn't a post about evh or chasing his tone. This is ONLY about the NFB circuit. A theoretical discussion 100%

Obviously every single clip that's been posted is with a stripe painted guitar and people playing symmetrical "scales."

That's obviously the reason the double variac idea exists in the first place, and its why amp chaser and other loons have gone into the flat earth conspiracy level about EVH tones

 

[harddriver]

The variac thing is definitely A sound, i'm just not remotely convinced it was THE sound of the shidd pants brown toan - I can actually play guitar and I've played a vintage plexi with everything on 10 before Anyone who has instinctively knows that there isn't really any secret to the amp, its the rest of the recording signal chain that really imparts the magic to that sound.

I guess with power stations, ox boxes, etc, and everything else out there, there are far better ways to skin that cat without destroying your transformers nowadays - christ, you can install a line out on a vintage marshall circuit, crank it up, put some kind of decent load on the amp, and slap IRs on, and you'll get way closer with way less danger to the amp IMO

The whole using the second variac as an impromtu attenuator was Chris Merren's explanation of why there were two variacs on top of the same head in 1977/78 pics, and as mentioned earlier since doing this tends to destroy output transformers this would correlate to the tales of Ed's amp blowing output transformers repeatedly in the early leg of the tour.

Is correlation causation???? Who knows? It's is an interesting correlation isn't it..........

I'm not making the argument that the tone can't be achieved 100% with a good Marshall SL/Plexi without it, plenty of clips out there showing that. I'm only saying the effects are very interesting when the variac is used this way and you really have to hear it yourself to decide what it does or doesn't bring to the table.

 

[harddriver]

Obviously every single clip that's been posted is with a stripe painted guitar and people playing symmetrical "scales."

That's obviously the reason the double variac idea exists in the first place, and its why amp chaser and other loons have gone into the flat earth conspiracy level about EVH tones

Well Dan...........you know all of Ed's Ohmite variacs were Jose modded.......c'mon man........................

 

[Exo-metal]

No one is discussing it here. Who cares in fact. The post is about fucking with the amp. So what if Ed did it. He opened the door but we're allowed to discuss what it does, aren't we?