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Bad bar electrical systems: Use a variable transformer on the supply?

If it truly is a voltage issue a voltage regulator may help. Merit Series 15 Amp Voltage Regulator | Furman Power | Purifying power for over 40 years.
This is NOT the same thing as a power conditioner, although it probably has that in it too. Voltage still has to be within its capture range or it will just shut down to protect from over under voltage levels. 90 to 141VAC output to +/- 120VAC. Although, like Aged said, I would question the amp itself.
 
Long story short, we play at a number of venues (mostly bars, old buildings with poor maintenance) that I believe have crappy power. I can hear it sometimes, amps do weird stuff, and also think it was probably the cause for my tube amp bias power supply, failing during a gig.

Based on that, is there any reason to use a variable output transformer coming from the "mains"?

Long version:

It's a 300 watt Eden E300T, about eleven years old. It would sound "funny" at some places, some distortion and reduced volume, line noise. After the gig that broke it, I checked the bias current (actually voltage across resistors) and it would drift from below normal to zero over a few seconds after power up. (Normal voltage drop across a resistor for each tube is proportional to current in this case.) I'm pretty sure I'll have to get the power supply board repaired. And I really really like this amp, even though I'm using one of the newer, more "powerful" non-tube amps right now. I miss my tone!!! And grunt.

Other people have had power issues at the one place in particular, to the point that one band I know has their drummer/electrician run a line to them directly from the breaker box. Lots of fridges, neon signs, fans, etc. for loads, all noisy and potentially low voltage. It's at a campground off of one utility transformer, lots of A/C units running in summer. (And yes, the drummer/electrician thing is kinda scary! lol)

Let's face it, if nothing is seriously broke, no bar or older venue owner is going to spend anything on upgrading their wiring.

I see that you can pick up a 10 Amp variable transformer for less than a hundred bucks. They look like the pic below. Note that these are NOT auto-transformers, they don't adjust themselves. It would provide noise protection, prevent ground loop issues, really big surges, smooth out the sine waves, and allow me to dial in the right voltage, even at the expense of drawing another amp off of the outlet; I don't care as long as any voltage adjustments are minor, it's only going to add maybe another Ampere max by raising the output 10V.

Or is there an alternate solution for "conditioning" crappy power available that doesn't cost a small fortune? Some sort of filter at least? It's nothing that a surge suppressor or "power distribution box" would address.

Thanks in advance for any help anyone can provide. Oh, and no, we're not going to stop playing those places, this is the reality of being a cover band that plays 30 gigs a year at maybe 20 different rural-regional venues; it's the only client base we have.

shopping
Ri
Long story short, we play at a number of venues (mostly bars, old buildings with poor maintenance) that I believe have crappy power. I can hear it sometimes, amps do weird stuff, and also think it was probably the cause for my tube amp bias power supply, failing during a gig.

Based on that, is there any reason to use a variable output transformer coming from the "mains"?

Long version:

It's a 300 watt Eden E300T, about eleven years old. It would sound "funny" at some places, some distortion and reduced volume, line noise. After the gig that broke it, I checked the bias current (actually voltage across resistors) and it would drift from below normal to zero over a few seconds after power up. (Normal voltage drop across a resistor for each tube is proportional to current in this case.) I'm pretty sure I'll have to get the power supply board repaired. And I really really like this amp, even though I'm using one of the newer, more "powerful" non-tube amps right now. I miss my tone!!! And grunt.

Other people have had power issues at the one place in particular, to the point that one band I know has their drummer/electrician run a line to them directly from the breaker box. Lots of fridges, neon signs, fans, etc. for loads, all noisy and potentially low voltage. It's at a campground off of one utility transformer, lots of A/C units running in summer. (And yes, the drummer/electrician thing is kinda scary! lol)

Let's face it, if nothing is seriously broke, no bar or older venue owner is going to spend anything on upgrading their wiring.

I see that you can pick up a 10 Amp variable transformer for less than a hundred bucks. They look like the pic below. Note that these are NOT auto-transformers, they don't adjust themselves. It would provide noise protection, prevent ground loop issues, really big surges, smooth out the sine waves, and allow me to dial in the right voltage, even at the expense of drawing another amp off of the outlet; I don't care as long as any voltage adjustments are minor, it's only going to add maybe another Ampere max by raising the output 10V.

Or is there an alternate solution for "conditioning" crappy power available that doesn't cost a small fortune? Some sort of filter at least? It's nothing that a surge suppressor or "power distribution box" would address.

Thanks in advance for any help anyone can provide. Oh, and no, we're not going to stop playing those places, this is the reality of being a cover band that plays 30 gigs a year at maybe 20 different rural-regional venues; it's the only client base we have.

shopping
R
Long story short, we play at a number of venues (mostly bars, old buildings with poor maintenance) that I believe have crappy power. I can hear it sometimes, amps do weird stuff, and also think it was probably the cause for my tube amp bias power supply, failing during a gig.

Based on that, is there any reason to use a variable output transformer coming from the "mains"?

Long version:

It's a 300 watt Eden E300T, about eleven years old. It would sound "funny" at some places, some distortion and reduced volume, line noise. After the gig that broke it, I checked the bias current (actually voltage across resistors) and it would drift from below normal to zero over a few seconds after power up. (Normal voltage drop across a resistor for each tube is proportional to current in this case.) I'm pretty sure I'll have to get the power supply board repaired. And I really really like this amp, even though I'm using one of the newer, more "powerful" non-tube amps right now. I miss my tone!!! And grunt.

Other people have had power issues at the one place in particular, to the point that one band I know has their drummer/electrician run a line to them directly from the breaker box. Lots of fridges, neon signs, fans, etc. for loads, all noisy and potentially low voltage. It's at a campground off of one utility transformer, lots of A/C units running in summer. (And yes, the drummer/electrician thing is kinda scary! lol)

Let's face it, if nothing is seriously broke, no bar or older venue owner is going to spend anything on upgrading their wiring.

I see that you can pick up a 10 Amp variable transformer for less than a hundred bucks. They look like the pic below. Note that these are NOT auto-transformers, they don't adjust themselves. It would provide noise protection, prevent ground loop issues, really big surges, smooth out the sine waves, and allow me to dial in the right voltage, even at the expense of drawing another amp off of the outlet; I don't care as long as any voltage adjustments are minor, it's only going to add maybe another Ampere max by raising the output 10V.

Or is there an alternate solution for "conditioning" crappy power available that doesn't cost a small fortune? Some sort of filter at least? It's nothing that a surge suppressor or "power distribution box" would address.

Thanks in advance for any help anyone can provide. Oh, and no, we're not going to stop playing those places, this is the reality of being a cover band that plays 30 gigs a year at maybe 20 different rural-regional venues; it's the only client base we have.

shopping
Right, was in a band with a master electrician/drummer who clipped band power upstream of the house breakers, huge difference...
 
A well designed amp will be well able to handle any of the ‘weirdness’ that the power grid sends them. If, in actuality, the supply is low then indeed the bias will sink but so will all the other supplies too.

If you want to be sure pick up a plug in AC voltmeter such as:

https://www.amazon.ca/SODIAL-80-300...+AC+voltmeter&qid=1560626150&s=gateway&sr=8-2

This will give you some indication of the actual supply voltage level.

Your VariAC idea is not such a good one.
 
Long story short, we play at a number of venues (mostly bars, old buildings with poor maintenance) that I believe have crappy power. I can hear it sometimes, amps do weird stuff, and also think it was probably the cause for my tube amp bias power supply, failing during a gig.

Based on that, is there any reason to use a variable output transformer coming from the "mains"?

Long version:

It's a 300 watt Eden E300T, about eleven years old. It would sound "funny" at some places, some distortion and reduced volume, line noise. After the gig that broke it, I checked the bias current (actually voltage across resistors) and it would drift from below normal to zero over a few seconds after power up. (Normal voltage drop across a resistor for each tube is proportional to current in this case.) I'm pretty sure I'll have to get the power supply board repaired. And I really really like this amp, even though I'm using one of the newer, more "powerful" non-tube amps right now. I miss my tone!!! And grunt.

Other people have had power issues at the one place in particular, to the point that one band I know has their drummer/electrician run a line to them directly from the breaker box. Lots of fridges, neon signs, fans, etc. for loads, all noisy and potentially low voltage. It's at a campground off of one utility transformer, lots of A/C units running in summer. (And yes, the drummer/electrician thing is kinda scary! lol)

Let's face it, if nothing is seriously broke, no bar or older venue owner is going to spend anything on upgrading their wiring.

I see that you can pick up a 10 Amp variable transformer for less than a hundred bucks. They look like the pic below. Note that these are NOT auto-transformers, they don't adjust themselves. It would provide noise protection, prevent ground loop issues, really big surges, smooth out the sine waves, and allow me to dial in the right voltage, even at the expense of drawing another amp off of the outlet; I don't care as long as any voltage adjustments are minor, it's only going to add maybe another Ampere max by raising the output 10V.

Or is there an alternate solution for "conditioning" crappy power available that doesn't cost a small fortune? Some sort of filter at least? It's nothing that a surge suppressor or "power distribution box" would address.

Thanks in advance for any help anyone can provide. Oh, and no, we're not going to stop playing those places, this is the reality of being a cover band that plays 30 gigs a year at maybe 20 different rural-regional venues; it's the only client base we have.

shopping


A variac is not really the right tool. What happens is when the band and all the kitchen equipment are pulling a heavy load, the voltage sags so you get a brown out. If the band has a big sound system the voltage can fluctuate pretty significantly with the music. Under these circumstances amps tend to distort at low power and sound anemic. Amps with protection circuity may even go into protect mode, so some Class D amps will not be a good choice. I believe digital gear tends to have more problems with low voltage as well.

The problem with a variac is it does not automatically compensate for dynamic conditions, so when you stop playing, the fryer in the back gets turned off, and the big freezer compressor is between cycles, suddenly you have an over voltage situation that is likely to fry your gear.
 
On an unrelated note, has anyone tried using a variac to simulate tube rectifier voltage sag?

I don't think you really get sag from this, but the amp will go into saturation at a lower volume/power level. Van Halen used to brown out his amps.

Dropping the voltage too much puts the heater voltage below spec. Some are concerned this can lead to cathode stripping.
 
I’ve had this problem with tube amps from guitar players at bars. The answer to the problem is the voltage regulator which are readily available and not cheap.
The power conditioner has nothing to do with this problem and will not solve it.
 
Long story short, we play at a number of venues (mostly bars, old buildings with poor maintenance) that I believe have crappy power. I can hear it sometimes, amps do weird stuff, and also think it was probably the cause for my tube amp bias power supply, failing during a gig.

Based on that, is there any reason to use a variable output transformer coming from the "mains"?

Long version:

It's a 300 watt Eden E300T, about eleven years old. It would sound "funny" at some places, some distortion and reduced volume, line noise. After the gig that broke it, I checked the bias current (actually voltage across resistors) and it would drift from below normal to zero over a few seconds after power up. (Normal voltage drop across a resistor for each tube is proportional to current in this case.) I'm pretty sure I'll have to get the power supply board repaired. And I really really like this amp, even though I'm using one of the newer, more "powerful" non-tube amps right now. I miss my tone!!! And grunt.

Other people have had power issues at the one place in particular, to the point that one band I know has their drummer/electrician run a line to them directly from the breaker box. Lots of fridges, neon signs, fans, etc. for loads, all noisy and potentially low voltage. It's at a campground off of one utility transformer, lots of A/C units running in summer. (And yes, the drummer/electrician thing is kinda scary! lol)

Let's face it, if nothing is seriously broke, no bar or older venue owner is going to spend anything on upgrading their wiring.

I see that you can pick up a 10 Amp variable transformer for less than a hundred bucks. They look like the pic below. Note that these are NOT auto-transformers, they don't adjust themselves. It would provide noise protection, prevent ground loop issues, really big surges, smooth out the sine waves, and allow me to dial in the right voltage, even at the expense of drawing another amp off of the outlet; I don't care as long as any voltage adjustments are minor, it's only going to add maybe another Ampere max by raising the output 10V.

Or is there an alternate solution for "conditioning" crappy power available that doesn't cost a small fortune? Some sort of filter at least? It's nothing that a surge suppressor or "power distribution box" would address.

Thanks in advance for any help anyone can provide. Oh, and no, we're not going to stop playing those places, this is the reality of being a cover band that plays 30 gigs a year at maybe 20 different rural-regional venues; it's the only client base we have.

shopping

We play a lot of outdoor festivals, that will likely not help you.

Educated guess........when the refrigeration or ac compressors kick in, voltage goes low.

That won't help.

Conditioning cleans ups noisy power.

We decided to ask for a dedicated circuit.
 
Long story short, we play at a number of venues (mostly bars, old buildings with poor maintenance) that I believe have crappy power. I can hear it sometimes, amps do weird stuff, and also think it was probably the cause for my tube amp bias power supply, failing during a gig.

Based on that, is there any reason to use a variable output transformer coming from the "mains"?

Long version:

It's a 300 watt Eden E300T, about eleven years old. It would sound "funny" at some places, some distortion and reduced volume, line noise. After the gig that broke it, I checked the bias current (actually voltage across resistors) and it would drift from below normal to zero over a few seconds after power up. (Normal voltage drop across a resistor for each tube is proportional to current in this case.) I'm pretty sure I'll have to get the power supply board repaired. And I really really like this amp, even though I'm using one of the newer, more "powerful" non-tube amps right now. I miss my tone!!! And grunt.

Other people have had power issues at the one place in particular, to the point that one band I know has their drummer/electrician run a line to them directly from the breaker box. Lots of fridges, neon signs, fans, etc. for loads, all noisy and potentially low voltage. It's at a campground off of one utility transformer, lots of A/C units running in summer. (And yes, the drummer/electrician thing is kinda scary! lol)

Let's face it, if nothing is seriously broke, no bar or older venue owner is going to spend anything on upgrading their wiring.

I see that you can pick up a 10 Amp variable transformer for less than a hundred bucks. They look like the pic below. Note that these are NOT auto-transformers, they don't adjust themselves. It would provide noise protection, prevent ground loop issues, really big surges, smooth out the sine waves, and allow me to dial in the right voltage, even at the expense of drawing another amp off of the outlet; I don't care as long as any voltage adjustments are minor, it's only going to add maybe another Ampere max by raising the output 10V.

Or is there an alternate solution for "conditioning" crappy power available that doesn't cost a small fortune? Some sort of filter at least? It's nothing that a surge suppressor or "power distribution box" would address.

Thanks in advance for any help anyone can provide. Oh, and no, we're not going to stop playing those places, this is the reality of being a cover band that plays 30 gigs a year at maybe 20 different rural-regional venues; it's the only client base we have.

shopping
This won’t correct voltage fluctuations—-
V in goes up, V out goes up.
V in drops, V out drops.
Nothing there to smooth out anything.
It’s a variable auto transformer, the primary and pseudo secondary share a common lead so no ground loop fixes.

Nobody (especially a qualified sparky)
is pulling a panel cover (and leaving it off) without arc flash protection.
The rules have changed in the last 10 years.
 
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Ha! I'm not talking about the little power strips people have always called "power conditioners". I'm talking about a really expensive unit that will correct slightly low or high voltage and costs hundreds.
View attachment 3446634
that is a “voltage regulator” which would indeed totally fit the bill. it’s a variac that self-adjusts to keep its output voltage constant.
View attachment 3446633

This thing works. It contains a continuous charging battery that in turn puts out a constant and clean ac. They use them to take out noise in signal for computers, it works for audio too.
computer UPS things don’t have the current to run big bass amps and power amps; they’re for stuff like computers and digital mixers and keyboards, things that get messed up if they lose power.