svt4 pro - sounding a little farty

[jcroxford]

So I just scored an svt4 pro with 2 pr410hlf cabs. When I was testing it out (in stereo) I didn't notice any issue, but then when I got it home and hooked up the bridge mono cord, it was lacking in power and distorted sounding. At first i though I made the cord wrong, but double checked it, and it was right.

So I then tested out each amp side on its own, and its the B side amp. A side is clean w/ lots of power. B - farty, very low power.

I was hoping maybe it was just a tube. So I bypassed the preamp, plugging a sansamp RBI in. A side fine, but B-Side same issue.

Does this sound l like anything that can be fixed at home or easily? Or am I facing the repair shop. Any advice would be appreciated. THX!

 

[agedhorse]

No, this is not a home fix. The B channel power amp has a failure which is why you also experienced the symptoms in bridge mode (which places the amps effectively in series)

Fins an Ampeg authorized service tech and it should be a straight forward repair.

 

[jcroxford]

Thanks. I will try and find a service center around town.

 

[agedhorse]

See if Rainbow Electronics is Ampeg authorized.

 

[BasturdBlaster]

My SVT4 did something similar to this and in my case it was the preamp in/ poweramp out jacks that needed to be cleaned. Maybe try some short patch cables in the FX loop and the preamp in/poweramp out loop on the "B" side of your amp.

 

[floridagatorfan]

One of my 4pros had a cold solder problem. Maybe this could be part of the problem on yours.