Ampeg GVT15H reverb problem

[SAMO]

Just picked up an Ampeg GVT15H head off the bay. Plugged it in and am getting this noise when I turn up the reverbhttp://s560.photobucket.com/user/plushsafehethink/media/IMG_0258_zpsc8c605b0.mp4.html
Any ideas on a fix?

 

[SAMO]

Contemplating just returning it to the buyer but I think I don't get reimbursed for the shipping which would be from NYC to New Mexico :-(

 

[Silent Sound]

Noisy reverb could be a lot of things. Depending on the noise, it could also just be the nature of the reverb circuit. Many are very noisy. It might be a good idea to get your hands on another one to make sure it's not just the way this amp is.

Let's see... I don't see any schematics for it, but it does apparently only have two 12ax7 tubes and two 6v6's. So I'd guess you have one 12ax7 for the preamp and one for the phase inverter. That means the reverb probably isn't tube driven, so replacing tubes probably won't help. I can't find any good pics of the inside of one either. Does it have a reverb tank? If so, I'd unplug those cables running to the tank and then replug them back in. Also, check those cables for any kinks or worn spots. There's a small possibility they could be bad.

In any case, those types of amps weren't really meant to be worked on, and while a really good tech wouldn't be too stymied by it, I doubt there's anything that you could do beyond checking those cables. As cheap as these amps are, especially used, I wouldn't take it to a tech. That would probably double your cost. Like I first noted, make sure that noise you're hearing isn't just a part of that particular amp first, and if the cables don't do anything, then I'd ask the seller for a refund. There's a big risk buying things online, and now you know that first hand.

 

[SAMO]

I pulled out the cables going to the reverb tank and the hum stopped!! So it's the reverb tank not the amp. Yeah, only two 12ax7 tubes…the first thing I did was to check and reseat the tubes and cables.
I told the seller we are all good if he pays for a new reverb tank, hasn't got back to me yet though lol.

http://s560.photobucket.com/user/plushsafehethink/media/IMG_0260_zps68017363.mp4.html

 

[SAMO]

I reversed the cables from the reverb tank…like plugged white into red and red into white and guess what…no hum and beautiful reverb!! lol Just heard back from Ampeg and was told, "I seem to remember there being one reverb tank that we were shipping that had the wire colors reversed from what was really there."
Totally bizarre…but otherwise a great sounding head for under $300.