Best $120 bucks I’ve spent in a long time.

[PDC]

A very good, life long friend of mine has been touring with a major band for a long time and recently had a break from dates due to the recent DELTA surge and large venue shows being cancelled. So he came by last week for an afternoon of strong drinks and loud amps. He brought some killer heads and his trusty Amp Rx Brown Box. I was stunned at what a difference it makes to knock the wall voltage down to an even, steady 110. Maybe for a non-MV amp where all of your gain and compression is coming out of the power tubes, you really need to go down to 90 volts. But for an amp with a good sounding MV, limiting the wall voltage to 110 is just incredible. (Voltage at my house was around 122-123 out of the socket.). Lead lines just sing, pick attack is smooth and articulate, the amp reacts like is WANTS you to sound incredible! I imagine this is what people are talking about when they say how much ‘feel’ Cameron amps provide. So, I ordered a 20 Amp Variac from Circuit Specialists:

https://www.circuitspecialists.com/variac-with-digital-display-tdgc2-2d.html
I ‘auditioned’ this thing today with my 50 Watt Marshall and my 50 Watt QR, and I could not be any happier. FWIW, the Brown Box only allows a reduction of maximum 10% from whatever the wall voltage is. So if your outlets are throwing 122-123, the most you can reduce them with the Brown Box is down to 110-111, which is perfect for a MV amp. But with a true Variac, you can wind the voltage down as far as you care or dare. And at $120 bucks compared to $300 +/- for the Amp Rx, the decision made itself.

 

[PDC]

I know, I know, no pics means it didn’t happen…

 

[Devin]

I bought one a while back. I notice almost no difference with it to be honest maybe because I haven't re-biased at the lowered voltage

it's a neat conversation piece regardless

 

[PDC]

I bought one a while back. I notice almost no difference with it to be honest maybe because I haven't re-biased at the lowered voltage

it's a neat conversation piece regardless

I absolutely agree that it is something I notice more in the way the amp reacts while I play as opposed to the sound in the room. The sound does change between 122 and 110, but I would not call it dramatic. The ‘feel’ is another story - when I wound it back up to wall voltage, the amp definitely felt ‘stiffer’ and less ‘reactive’ as I played.

 

[Donnie B.]

it's a neat conversation piece regardless

Need to try this on the wife one of these days.

 

[DanTravis62]

In my area certain venues are NOTORIOUS for having 127-128 type voltage coming out of their sockets.

Everyone knows without something to knock it down you'll sound like shit.

 

[fek]

I keep toying with buying a Variac. Just need to do it.

 

[rottingcorpse]

Need to try this on the wife one of these days.

Fuck.Beat me to it.

 

[Rick Lee]

I have that same one. You should really get an accurate baseline of your wall voltage with a multimeter and then see if the Variac shows that same voltage at that setting before you rely on it. Mine was pretty off, so I loosened up the set screw and reindexed the dial. My wall voltage is a pretty steady 123VAC.

 

[Sharkattack3]

So is that a decent/safe model Variac? I just got a Ceriatone Plexi 50 and I've been eyeing one. I was worried I needed to drop several hundo, but I guess not.

 

[PDC]

I have that same one. You should really get an accurate baseline of your wall voltage with a multimeter and then see if the Variac shows that same voltage at that setting before you rely on it. Mine was pretty off, so I loosened up the set screw and reindexed the dial. My wall voltage is a pretty steady 123VAC.

I noticed the same thing - but I found that the flat spot on the dial post prevents me from rotating the plastic knob far enough to get the point on the dial to match the number in the display. But I did verify that the display reading does match both outputs on the unit with a multimeter.

 

[Rick Lee]

You should be good to go then. Next time I have my 100w Plexi clone chassis on the bench, though it already has a Variac feature built in, I will turn the external Variac down until the plate voltage is 350VDC, bias around 70%, write everything down, play real loud for a while and then use the wall voltage only and internal Variac feature to compare values and tones.

 

[ericb]

That's pretty interesting. I bought a little Digital Voltage meter to check voltages a few weeks back. . Mine is 120 at home and I've only done this test with my Splawn Competition.. It sounds great at 120. . I then had a gig with 113 volts. . Sounded nowhere near as good. . Last night's gig measured 116 volts . . Sounded great. . . I have a gig tomorrow too and I'm going to check again.. SO FAR though I'm definitely not liking the lower voltage with the Splawn. . . . I have loads of other amps and haven't done any testing so don't know, but I do have a THD Series 1 Plexi with a built in variac and I like lower voltage with that a lot , but not necessarily more than the normal voltage. It's quite a decent change though in feel and a bit with tone

Eric

 

[blackba]

The 20Amp variac is overkill, but sure will handle any amp that I have seen. I have a few variacs, one for the bench, one for my vintage amps, and a cheapie circuit specialists 5A model. https://www.circuitspecialists.com/...UvRxfo7RzlSOFoE2O9YW1sco3Eq51hj0aAvHEEALw_wcB

I tend to set my amps up where the heater voltage is exactly 6.3V and bias there. You do want to be careful going too low for the heater voltage, 110Vac should be fine. I like to lower the voltage on the vintage amps to give everything more margin, difference in sound has generally been slight, but I am usually running 112-115VAC, depends on the amp.

I also have a brownie and that has been great when I travel. Best thing about controlling the voltage, the tone is more consistent as well. And for those who can score a used USA variac, grab a kill-a-watt so you know the exact voltage. The display on the circuit specialists ones is within a volt or two.

 

[Rick Lee]

I wouldn't expect an amp to sound great by just lowering the voltage with a Variac. You also need to adjust the bias relative to the lower PV.