Anyone using a Variac with their Marshall Head?

flyinguitars

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Wondering if you've noticed any difference with tone?

My son is in a VH tribute and has switched over from a Kemper to using my jcm800 heads. He's using an attenuator, phase 90, and flanger and that it. The tone is killer and he loves the feel and response. The only issue is that the different venues can have sketchy power. Some have under or over voltage and he's had some issue with buzzing and what sounds like white noise in some of the venues. In some places the amps are quiet so it's a power or interference issue.

So we were considering something like the Furman ac117 that filters the power and supplies a steady 117 volts even if power is lower voltage. I had one years ago and it kept my rig quiet. I think the new counterpart model Furman p1800 is about $1500, so it's not a cheap remedy.

Then we were thinking instead of an expensive combination power filter/regulator like the ac117, p1800, or similar, why not buy a separate EMI/RFI filter and get a Variac to regulate the voltage.....and then he can dial down the voltage and try to get that EVH sag. If it sounds like shit or no improvement, then just set it to 120v and the amp should be fed steady voltage.

Thoughts or experiences?
Thanks!
 

flyinguitars

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That's it! The 89v demo sounds like it has more sizzle. There is a sag adjustment on the Kemper and I've noticed the same as he described when adding more sag.....it gets kind of loose and feels sloppy. I've also noticed that when we dial in a really close VH tone, it's kind of hard to play, as in that genuine brown sound really makes you work to pull the right sounds out.


Going to need a 1959 ;-)

Yea going to need one no matter what .haha
 

playloud

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Yea going to need one no matter what .haha

I'd rather spend $1500 on a 1959 than that Furman!

I run something like this. I use a dual-conversion (online) UPS, which converts mains AC -> DC -> much "cleaner" 230V AC (+/- 0.2V). I then use the variac after that, and can be confident that the setting I choose will remain stable throughout a playing session. I also use a cheaper Furman between the UPS and variac, but I'm not really convinced it's not just snake oil (I really use it to get more sockets).

The issue with your approach is that the variac doesn't provide any kind of voltage regulation - it just multiplies the input power by a constant. So if the mains power goes from 115V to 125V over an hour, your post-variac power will go from (say) 85V to 92V over the same period. If you're doing the proper "brown sound" thing, you'll bias the amp to the intended post-variac voltage, so these shifts pose similar problems to shifts at full voltage.
 

Matthews Guitars

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I always have a variac feeding two of my JMP 1959s. It's a 2KVA Powerstat, (edited to remove extra zeroes) so it has all the capacity needed to drive both at once with no sweat. (Full 15A rated.)

With it set to 90 volts (120 volt wall voltage here) two things happen: The amp delivers less power, so the volume becomes less oppressively amazingly stupefyingly loud, and it does change the distortion character in a way that many people would find to be more musical.
 
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flyinguitars

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I'd rather spend $1500 on a 1959 than that Furman!

I run something like this. I use a dual-conversion (online) UPS, which converts mains AC -> DC -> much "cleaner" 230V AC (+/- 0.2V). I then use the variac after that, and can be confident that the setting I choose will remain stable throughout a playing session. I also use a cheaper Furman between the UPS and variac, but I'm not really convinced it's not just snake oil (I really use it to get more sockets).

The issue with your approach is that the variac doesn't provide any kind of voltage regulation - it just multiplies the input power by a constant. So if the mains power goes from 115V to 125V over an hour, your post-variac power will go from (say) 85V to 92V over the same period. If you're doing the proper "brown sound" thing, you'll bias the amp to the intended post-variac voltage, so these shifts pose similar problems to shifts at full voltage.
Ok good info..thanks. I was hoping that the Variac provided a steady voltage based off of the output setting. We get a pretty good brown sound already but I was hoping that this would be a way to kill two birds by keeping the voltage constant and having the ability to lower it into the VH sweet spot..lol.

We may just pick up a used regulator to relegate the voltage discrepancies from venue to venue and get a Variac to try out. Do you like the Variac sound/effect?

I always have a variac feeding two of my JMP 1959s. It's a 2000 KVA Powerstat, so it has all the capacity needed to drive both at once with no sweat. (Full 15A rated.)

With it set to 90 volts (120 volt wall voltage here) two things happen: The amp delivers less power, so the volume becomes less oppressively amazingly stupefyingly loud, and it does change the distortion character in a way that many people would find to be more musical.
Great thanks for the info. Do you like it?
Is it a 2kva or 2000kva?
Thanks!
 

Matthews Guitars

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I wouldn't still be using it if I didn't like it. It's a permanent part of my twin stack setup as far as I'm concerned.
 

playloud

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Ok good info..thanks. I was hoping that the Variac provided a steady voltage based off of the output setting. We get a pretty good brown sound already but I was hoping that this would be a way to kill two birds by keeping the voltage constant and having the ability to lower it into the VH sweet spot..lol.

We may just pick up a used regulator to relegate the voltage discrepancies from venue to venue and get a Variac to try out. Do you like the Variac sound/effect?

It's cool as an effect. I don't really shoot for the 'brown sound' 24/7 (play cleaner mostly) so it's not an always-on thing, but it's fun to have. Another color in the palette if you will.

Having a variac is also useful if you need to start up amps which have been stored for a long time (or new builds).
 

Matthews Guitars

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The difference in volume level between a cranked Superlead at 120 volts and a cranked Superlead at 90 volts is considerable, and there's no tone suck. I have a Marshall Power Brake, and it works well, but I'd be lying if I told you that it didn't have some negative consequences on the tone. Of course, the more attenuation I dial in, the more it affects the tone.

Using both the power brake and the Variac makes a nice combination. I can really get the volume level down without much tonal compromise.
 

Mike.Welch

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Instead of using a variac, I built an amp that runs 340 vdc on el34 plates and it really sounds great. The lower plate voltage really make most output tubes sound better (to my ears). And I still have around 6.3 volts on my heaters.

With a variac turned way down, your heater voltages might be out of specs. I have heard that heater voltages that are too low can cause damage over time.
 

flyinguitars

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It's cool as an effect. I don't really shoot for the 'brown sound' 24/7 (play cleaner mostly) so it's not an always-on thing, but it's fun to have. Another color in the palette if you will.

Having a variac is also useful if you need to start up amps which have been stored for a long time (or new builds).
Sounds good thanks! Yea I was just building off of his issue with power noise. Trying to turn a problem into some extra fun.haha.
His main issue is a sometimes noisy amp. He plays in two bands that both do decent size venues. One with me in an Ozzy tribute and the other band is a VH tribute.....so for that band it's brown sound all night. I think I'm going to look for decent used power regulator, pick up stand alone filter, and get a Variac....fuck it...lol.


The difference in volume level between a cranked Superlead at 120 volts and a cranked Superlead at 90 volts is considerable, and there's no tone suck. I have a Marshall Power Brake, and it works well, but I'd be lying if I told you that it didn't have some negative consequences on the tone. Of course, the more attenuation I dial in, the more it affects the tone.

Using both the power brake and the Variac makes a nice combination. I can really get the volume level down without much tonal compromise.
Good info thanks.... he's using a Weber attenuator with the jcm 800s to knock some volume off. The heads were modified by our local amp guru and they sound killer but they are 100w and as you know, loud as it gets. If the Variac reduces volume, that would be a win win.
Instead of using a variac, I built an amp that runs 340 vdc on el34 plates and it really sounds great. The lower plate voltage really make most output tubes sound better (to my ears). And I still have around 6.3 volts on my heaters.

With a variac turned way down, your heater voltages might be out of specs. I have heard that heater voltages that are too low can cause damage over time.
Cool...what kind of sound does your amp have?
I'll look into the effects of running those particular amps with a Variac and try to figure out a safe threshold. He's playing 2 hour shows 4-8 times a month, so if it's an issue it probably won't take long to surface.
 

Mike.Welch

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Sounds good thanks! Yea I was just building off of his issue with power noise. Trying to turn a problem into some extra fun.haha.
His main issue is a sometimes noisy amp. He plays in two bands that both do decent size venues. One with me in an Ozzy tribute and the other band is a VH tribute.....so for that band it's brown sound all night. I think I'm going to look for decent used power regulator, pick up stand alone filter, and get a Variac....fuck it...lol.



Good info thanks.... he's using a Weber attenuator with the jcm 800s to knock some volume off. The heads were modified by our local amp guru and they sound killer but they are 100w and as you know, loud as it gets. If the Variac reduces volume, that would be a win win.

Cool...what kind of sound does your amp have?
I'll look into the effects of running those particular amps with a Variac and try to figure out a safe threshold. He's playing 2 hour shows 4-8 times a month, so if it's an issue it probably won't take long to surface.
It is a high gain Marshall Circuit based on the Ceriatone Chupacabra. Very aggressive sound. Needs no pedals, but pedals sounds great with the amp. The preamp is exactly like the Chupacabra, but the output section is like a Trainwreck express with a 6.6K primary impedance. The output tubes are cathode biased. The output transformer can handle up to 30 watts, so I can use almost any tube octal I want in it and the bias current will stay within acceptable range. I have used 6V6, 6L6, 5881, EL34. I have experimented with a lot of different tubes and each seems to give the amp a little different sound. I have never heard a sound that I did not like from that amp. I measured it at 20 watts with 6V6 output tubes. I have experimented with affect of different B+ voltages and I like to get the output tubes down to around 340-350 volts DC. That seems to be the sweet spot for me. Also, the plate voltage of the first stage is around 70-80 volts DC, which is ridiculously low, but it works good in my amp.
 

mickeydg5

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Wondering if you've noticed any difference with tone?

My son is in a VH tribute and has switched over from a Kemper to using my jcm800 heads. He's using an attenuator, phase 90, and flanger and that it. The tone is killer and he loves the feel and response. The only issue is that the different venues can have sketchy power. Some have under or over voltage and he's had some issue with buzzing and what sounds like white noise in some of the venues. In some places the amps are quiet so it's a power or interference issue.

So we were considering something like the Furman ac117 that filters the power and supplies a steady 117 volts even if power is lower voltage. I had one years ago and it kept my rig quiet. I think the new counterpart model Furman p1800 is about $1500, so it's not a cheap remedy.

Then we were thinking instead of an expensive combination power filter/regulator like the ac117, p1800, or similar, why not buy a separate EMI/RFI filter and get a Variac to regulate the voltage.....and then he can dial down the voltage and try to get that EVH sag. If it sounds like shit or no improvement, then just set it to 120v and the amp should be fed steady voltage.

Thoughts or experiences?
Thanks!
If constant power is the issue than get a regulator.
I like Furman.
 

flyinguitars

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It is a high gain Marshall Circuit based on the Ceriatone Chupacabra. Very aggressive sound. Needs no pedals, but pedals sounds great with the amp. The preamp is exactly like the Chupacabra, but the output section is like a Trainwreck express with a 6.6K primary impedance. The output tubes are cathode biased. The output transformer can handle up to 30 watts, so I can use almost any tube octal I want in it and the bias current will stay within acceptable range. I have used 6V6, 6L6, 5881, EL34. I have experimented with a lot of different tubes and each seems to give the amp a little different sound. I have never heard a sound that I did not like from that amp. I measured it at 20 watts with 6V6 output tubes. I have experimented with affect of different B+ voltages and I like to get the output tubes down to around 340-350 volts DC. That seems to be the sweet spot for me. Also, the plate voltage of the first stage is around 70-80 volts DC, which is ridiculously low, but it works good in my amp.
Wow sounds killer! Thanks for the info!

If constant power is the issue than get a regulator.
I like Furman.
Yea, I was hoping that a Variac regulated power. Going to pick up a regulator and a variac.
 

fuzz1222

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Wondering if you've noticed any difference with tone?

My son is in a VH tribute and has switched over from a Kemper to using my jcm800 heads. He's using an attenuator, phase 90, and flanger and that it. The tone is killer and he loves the feel and response. The only issue is that the different venues can have sketchy power. Some have under or over voltage and he's had some issue with buzzing and what sounds like white noise in some of the venues. In some places the amps are quiet so it's a power or interference issue.

So we were considering something like the Furman ac117 that filters the power and supplies a steady 117 volts even if power is lower voltage. I had one years ago and it kept my rig quiet. I think the new counterpart model Furman p1800 is about $1500, so it's not a cheap remedy.

Then we were thinking instead of an expensive combination power filter/regulator like the ac117, p1800, or similar, why not buy a separate EMI/RFI filter and get a Variac to regulate the voltage.....and then he can dial down the voltage and try to get that EVH sag. If it sounds like shit or no improvement, then just set it to 120v and the amp should be fed steady voltage.

Thoughts or experiences?
Thanks!
I have a Variac I’ve used with my 1959HW, it’s great for those tones. I have recently spent a lot of time working on making Kemper profiles of this set-up, with the Echoplex type boost, 10-Band EQ in line.. going to be releasing a pack couple of weeks with 10-12 snapshots of the Brown Sound included, plus 40-50 other profiles with different classic cabs. I could play the Brown Sound profiles all day long. So much fun!

Website for anyone interested is:

www.blittleprofiles.com

You can check out sound clips of my other packs as well on YouTube:


B
 

curt miller

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Wondering if you've noticed any difference with tone?

My son is in a VH tribute and has switched over from a Kemper to using my jcm800 heads. He's using an attenuator, phase 90, and flanger and that it. The tone is killer and he loves the feel and response. The only issue is that the different venues can have sketchy power. Some have under or over voltage and he's had some issue with buzzing and what sounds like white noise in some of the venues. In some places the amps are quiet so it's a power or interference issue.

So we were considering something like the Furman ac117 that filters the power and supplies a steady 117 volts even if power is lower voltage. I had one years ago and it kept my rig quiet. I think the new counterpart model Furman p1800 is about $1500, so it's not a cheap remedy.

Then we were thinking instead of an expensive combination power filter/regulator like the ac117, p1800, or similar, why not buy a separate EMI/RFI filter and get a Variac to regulate the voltage.....and then he can dial down the voltage and try to get that EVH sag. If it sounds like shit or no improvement, then just set it to 120v and the amp should be fed steady voltage.

Thoughts or experiences?
Thanks!
I'm getting ready to order a Germino 55LV. I will buy a top of the line Variance to add to the tone, plus to regulate the varying voltages from club to club.

Go for it.
 

AR999

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There is a great piece of gear to solve your voltage regulation problems, check out the AmpRX -BrownBox. It’s the best product I’ve seen to save your amp and your tone.

I think it was around $350 new and I use it with my modded 1959 every time I turn the amp on.
 

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