Voltage was a little high the other night.

psychodave

Well-known member
Glad I have a brown box to keep things under control. I have my main amp and rack with a Strategy 400 plugged in. Bringing it down to 113 really changes the amps tone and feel plus keep is running in specs to the 117-120 they were designed for.

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Love mine as well. House is typically 123 which feels stiff and bright. I set it around 115 which really warms up and loosens the feel
 
If you’re using a Bogner XTC and have the class A/AB switch, if you’re anything over 115V into the amp you’ll redplate the EL34s in class A. The high B+ doesn’t give much wiggle room to variances of wall voltage into the amp.
 
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If you’re using a Bogner XTC and have the class A/AB switch, if you’re anything over 115V into the amp you’ll redplate the EL34s in class A. The high B+ doesn’t give much wiggle room to variances of wall voltage into the amp.
I had a Groove Tubes amp that I had this problem with. The class A setting was really fun to play until the wall voltage set it into catastrophic failure mode. Where I live in Ca very few of the homes have updated electrical and these homes were built in the 30’s/40’s mostly. Noisy and unpredictable.
 
I guess I got lucky I've run my 101B in class A many times at 123 wall voltage with no issues. Using normal cheapo JJ EL34's. I just don't like the sound of the class A setting.
 
My house voltage can be all over the place. 120v and later at night can hit 128v. I use a variac now with a digital display on the front to keep things in the 117 to 120 range and all is well.

The Brown Box looks really cool though, and still would like one for the mobility, but I don't move my gear around these days.
 
I use a variac with my vintage amps, usually set between 110 to 115VAC and biased them accordingly. I do have an Amprx brownie (which is smaller than the brown box). Good for taking out, the variac stays at home. I use one of those Kill-A-Watts to know the voltage on the variac, as its an old USA one.
 
Not sure what amps you have, but this one will cover most amps (hand full of bass amps, 5Amps wouldn't be enough). The votlage display is pretty accurate as well. That is the biggest concern with a variac you can overvoltage your gear if you are not careful. https://www.circuitspecialists.com/...MI3e7i64eh-gIVUhXUAR0Vag88EAQYAiABEgJ5IPD_BwE

The one you linked to is 20A and overkill. The voltage readout is not going to be super accurate either, but should work. If you are lucky you can score a vintage USA variac for like $20, but then you need a killawatt or something like that to know the voltage.
 
Not sure what amps you have, but this one will cover most amps (hand full of bass amps, 5Amps wouldn't be enough). The votlage display is pretty accurate as well. That is the biggest concern with a variac you can overvoltage your gear if you are not careful. https://www.circuitspecialists.com/...MI3e7i64eh-gIVUhXUAR0Vag88EAQYAiABEgJ5IPD_BwE

The one you linked to is 20A and overkill. The voltage readout is not going to be super accurate either, but should work. If you are lucky you can score a vintage USA variac for like $20, but then you need a killawatt or something like that to know the voltage.
tremoverb...and probably a dsl this week.
 
I’m in the U.K. and most of my amps are 230v (but a couple 240v). However my wall voltage is usually 246v to 250v. Actually really stable in that region. Likely too high for a 230v amp.

I’ve been meaning to build a bucking transformer for a while, I’ve got a 20 volt Center tapped transformer and all the parts, just been dragging my feet.

Amprx make a euro version of the brown box but I just can’t stomach the price.
 
Not sure what amps you have, but this one will cover most amps (hand full of bass amps, 5Amps wouldn't be enough). The votlage display is pretty accurate as well. That is the biggest concern with a variac you can overvoltage your gear if you are not careful. https://www.circuitspecialists.com/...MI3e7i64eh-gIVUhXUAR0Vag88EAQYAiABEgJ5IPD_BwE

The one you linked to is 20A and overkill. The voltage readout is not going to be super accurate either, but should work. If you are lucky you can score a vintage USA variac for like $20, but then you need a killawatt or something like that to know the voltage.
This looks good. I’d just confirm with a quality meter that the visual output is correct. 👍
 
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