Current starvation?

[surfdog777]

I posted this question on the Marshall forum, but so far no replies, so here goes:

For the electrical engineers:

Could a light tree (4 x 300w par 56) plugged into the same outlet as my amp pull enough juice from the line as to change (diminish) the amp's performance? It should also be noted that the tree and amp were both plugged into an outlet strip that was fed from a 12 or 14 gauge extension cord.

This happened at a gig last night, at first I passed it off as a bad cord, loose connection, etc ... but today hooked it up again (at home) and all seems fine....

The possiblity that it could have been the lights didn't occur to me until today when I was bangin' the head trying to figure out what was hooked up differently.

Thoughts?

[David McCarroll]

4 x 300watts means the lights are drawing (1200/120volts) 10 amps of current, so unless the wall socket is rated at comfortably above 10 amps, then, yes, you will possibly have an issue - any load at all on a mains supply will diminish the voltage, it depends upon how far it diminishes the voltage before you start to notice.

Having said that, at least here in Australia where we have 240v power, it is relatively common to plug all the audio equipment into 1 socket to avoid ground loops, lights almost always will end up on a different circuit, as they will most likely draw more current than the entire PA/backline put together.

Does that help?

[Racerx2k]

+1. It can most definitely do that. In some cases, people have actually starved the amp, intentionally, which is how EVH got his "brown sound", utilizing a variac, and sagging the power to the amp(s). If it can make your sound "better", I'm sure it can also make it "worse", too, given the situation.
It has been rumored that Paul Gilbert did this same thing, teaching at GIT, using a toaster! hehe. That Paul, what a card! hehe.

[surfdog777]

Thanks guys, from now on the lights will go on a different circuit.