What are the symptoms of low voltage?

[George Kimery]

Saturday night, my Quilter wasn't itself. The only place I had to plug in was an outlet that the house had mounted one of those square 6 outlet boxes onto. The first thing I noticed when I turned my amp on, was very low volume. I checked cords and amp settings but found nothing wrong. I had to crank up the amp wide open to get usable volume. The next problem was, all highs. So bright it could peel paint. I cut the Hi-Mids and Treble all the way off. Still nothing but high shrill. I finally got the highs down by using the tone control on my guitar. I never did get the sound quality to where it should have been. Only thing I can think of is that coming out of the 6 way wall mounted adapter, I wasn't getting enough voltage. The only thing plugged into this particular outlet was me and a light fixture.

The whole stage is probably on one circuit, so the amps from the PA, the fiddle, bass, and lead guitar may have been eating up current as well

What do you think? Amp has always been fine at other venues and at home. It worked fine at home the day of the gig and the day after.

[Georg Sørtun]

Depends on type of amp, but in general the signs of low mains voltage is lowered output power and early onset of distortion.

[Tim Marcus]

on a class D amp, with a class D power supply, I doubt you would notice any low voltage symptoms.

my half and half, for example, has a universal power input for the class D part meaning that anything from 100-240 volts on the input yields the same 300W output. If Quilter is exporting his amps, I would imagine that they put in a similar universal input supply.

another thing to consider: you can run a band with a PA and make a fair amount of noise without even coming near the 15 or 20 amp limit on a single circuit. If someone was running a space heater, or a hair dryer, or a coffee pot or something I could see the voltage dipping down - but a few amps? not going to draw much current.

I would check other things in your signal path - starting with the cables.

[George Kimery]

Cables are 100% good. They are George L cables soldered into Switchcraft plugs. I was extremely careful to make sure they were soldered correctly and have checked them with a meter.

I know to take an amps output and divide by 117 to get the amps being used. Tim, you are quite right that it would take quite a few amps to eat up a 20 amp circuit.

The venue was one that I have played many times before without any problem. I will go better prepared if I play there again. I have a voltage meter that I will take along just to check out the current output.

So I guess low voltage was not the problem. Everything is working great back at home. I have another gig Friday night in a different venue. I will see what happens. I can go from my rack mount Quilter to my backup rack mount Carvin BX 500 in just a few seconds, so if I have the same problem Friday night, I will jump from the Quilter to the Carvin and see what happens.

Thanks for the help.

[Craig Baker]

Tim is correct.
One thing the Supreme Court hasn't repealed is Ohm's law.

Whether you use a Milkman amp, a Peavey amp, or a Fender amp, a few amps will only draw a few amps.

Craig

[chris ivey]

..few amps is a few amps...har har.
i bet it was the weird wall plug thingie.

[Tony Prior]

..few amps is a few amps...har har.
i bet it was the weird wall plug thingie.

Yes this can be the case.

Carry one of those yellow wall AC power phase things you get from Lowes. Start there with any suspect AC power issues.

It wasn't mentioned if the PA or any other amp was having an issue... 15 or 20 amps is a bunch of juice !

[Donny Hinson]

Just because you have a 20 amp breaker in the mains panel does not mean that there's 20 amps available at the outlet! There are voltage drops, both inside and outside the structure, that affect the amount of power available. Having a poor connection somewhere can also add to the problem. Carry a cheap voltmeter, or even better, a "KILL-A-WATT" device to see what's really going on - how much voltage is available, and how much current your gear is drawing, and you may be surprised.

[Les Cargill]

..few amps is a few amps...har har.
i bet it was the weird wall plug thingie.

Yes this can be the case.

Carry one of those yellow wall AC power phase things you get from Lowes. Start there with any suspect AC power issues.

It wasn't mentioned if the PA or any other amp was having an issue... 15 or 20 amps is a bunch of juice !

Yes, but...

I have an Ampeg B4R (900W) and there were places where it would not boot up right away. It has a micro that stops the startup sequence if the wall power isn't adequate while it's charging the big caps. You'd have to make two, three, four tries to get it to come up ( announced by the click of a relay ) .

900/4 is 225. sqrt(225) is about 15 amps. That's at the speaker output. So it might actually draw 15 or more if you used all of it.

I generally didn't use enough of the 900W for it to cut out (as you might imagine). I let the bandleader tell me how loud to play. With great power comes great responsibility... but sometimes you play outside...

Oh, and earplugs good.

[Les Cargill]

I've sent support emails to Quilter, and always gotten a direct response from Pat himself. I'd do that.

[Charlie Thompson]

George are you using the loop for the Volume pedal?
I found the built in buffer use for that loop to be extra bright

[Dick Wood]

Was the amp on a chair? You can loose a bunch of bottom raising an amp off the floor.

[John Billings]

It's the bass player's fault!

[John McClung]

I've encountered enough low voltage lines that destroyed my tone and volume that, like many others, I've installed the Furman AR-1215 Power Conditioner + Regulator in my rack. Heavy as hell and a drag to lug around, but it has led lights that tell me what the voltage is, does all it can to regulate it, and if it can't, shuts down and prevents my having a rack full of gear damaged or destroyed by crappy power sources.

Does anyone know if there is a similar rack unit device that does the same thing and isn't such a boat anchor??

[John Billings]

I have a Balance transformer. Weighs a ton! Requires 240 volts, but supplies a steady 120. Used in hospitals, etc..

[Carl Mesrobian]

Kill A Watt or a DMM sounds like a good idea. See what is going on through a "good outlet" and use that as a benchmark.

[John Billings]

I have used a meter at gigs, and when the bass player plays low and loud, I've seen the voltage drop a lot.

[Carl Mesrobian]

I have used a meter at gigs, and when the bass player plays low and loud, I've seen the voltage drop a lot.

Bass players are usually the cause of any problem at a gig..

[Edward Rhea]

Scrawny extension cords between the amp/wall, can cause problems for you as well...

[Carl Mesrobian]

Just because you have a 20 amp breaker in the mains panel does not mean that there's 20 amps available at the outlet! There are voltage drops, both inside and outside the structure, that affect the amount of power available. Having a poor connection somewhere can also add to the problem. Carry a cheap voltmeter, or even better, a "KILL-A-WATT" device to see what's really going on - how much voltage is available, and how much current your gear is drawing, and you may be surprised.

People doing their own electrical work is a scary thought, too. Putting under valued wire gauge for home runs , etc. Don't go there In fact you'd be better off just finding another outlet at the venue to plug into, and just say "that one works funny"