weird volume/power problems with my rig. help!

[thundernahnahah]

my setup mesa triaxis
g-major
rocktron velocity 100 power amp
rocktron midimate footcontroller

ok basically the problem is this. Whenever i'm playing live, after about 6 songs my amp just loses power completely and the volume of the thing goes way down. This never happens at rehearsals so i can't distinguish the problem. When i'm playing live i'm switching between presets a lot, could this b the problem? I don't think its a lead problem either. There is still a signal coming through but weak. would gr8ly appreciate if some1 cud help me, cheers

 

[MesaGod666]

This could be a number of things.

Are you using a power conditioner?
What is your wiring configuration?
What cables are you using/how clean is your rig?

Posting some pictures of your rig can help us help you with your problem.

 

[Screamindv]

A power conditioner only cleans up the power. Quite often, as the band plays louder, the voltage can drop to 110 volts or lower because of the demand for elictricity from big power amps that might be sharing circuits with lights. When the voltage drops,the tubes don't have enough voltage to power properly. The first sign of this happening is distortion of amps. Another tell tale sign is feedback between songs. Engineer turns up PA to compensate for loss of power. End of song comes and everybody stops playing. PA now gets full power and mics start to feedback. If this happens with all presets, the culprit could also be power amp tubes Low voltage can cause premature wear of power amp tubes. Try a power regulator like the Furman ar117 or ar120. See if that helps.