Amp Tech help needed...

[Shep]

this is the problem

I own a U.S power Mk IV and a AUST powered marshall Jcm 800 reiusse..I live AUST so i have to use a tranny to change the voltage...it is the correct tranny to 240-120...

i want to run the two amp's via a A/B box into two different speaker cab's.. that sounds pretty easy to do...YEAH...guitar-A/B...A to mk iv...B to Marshall...and a speaker cab running off each head.....

Well...i get this huge hum...huge..It's only happens when both are pluged in if i un-plug one of them it goes...it's not leads...it not a guitar..i think its somthing with the earth between the two amp's...i am no tech but this is all i can think of..both amp's by them selve's are perfect....I MEAN PERFECT queit....i am going to get a radial head bone VT but i don't want to get it if i get the same result....BTW if i use my aust power peavy insteed of my mk iv it doesn't do it ,it works great.......

Does any one have any idea why this is doing it.....or how i can fix it...



Thanks Tom

 

[Boogiebabies]

 

[t0aj15]

My setup includes four amps so I understand your problem. It is a ground loop issue. This is how I solved that problem, it works great:
http://www.voodoolab.com/ampselector.htm

 

[LHanson]

Might try lifting the ground on one of the amps.

 

[Shep]

would the Radial headbone VT do the same thing as the voodoo lab? ... it would be alot more easy if i used one cab insteed of 2 quads....

 

[Shep]

http://www.tonebone.com/tb-headbone-vt.htm

there it is....

 

[JOEY B.]

I use a pedal made by a company called Lehle to switch between or combine my two amps. They call it the DUAL. You can see it at www.lehle.com

 

[Shep]

thats looks cool but doesn't able me to only hav one cab with the two heads...

 

[JOEY B.]

You might want to try a Recto 4x12 or wire your cabinet for a stereo 2x12 operation. The blending of two different amps can sometimes get you the best of both worlds.