Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Eddy6120 on February 21, 2015, 01:23:24 pm

Title: Vox AC15c1 problems
Post by: Eddy6120 on February 21, 2015, 01:23:24 pm

Hey All, newbie here, Thank you Doug for referring me to this forum.
Here is my problem: My Vox AC15c1 (China) is making "booming" noises at the moment, along with the bass going in & out in the top-boost channel, & when plugged into the normal channel with the master on full & the volume all the way down I still get sound coming through. (sometimes it will work correctly, then all of a sudden it will malfunction & boom out full blast)  I have changed & switched around the tubes & also cleaned the pots with contact cleaner. Any advice would be greatly appreciated...  Thank You in advance!   

Title: Re: Vox AC15c1 problems
Post by: EL34 on February 21, 2015, 06:26:51 pm

The other guys may know more about this amp than I do.


Is this a PC board amp?

Title: Re: Vox AC15c1 problems
Post by: HotBluePlates on February 21, 2015, 06:37:42 pm

Sounds like an intermittent ground and/or loose/intermittent ribbon cable or other connector.

Title: Re: Vox AC15c1 problems
Post by: Willabe on February 21, 2015, 06:53:46 pm

Agree, and/or cold solder joint.


             Brad   

Title: Re: Vox AC15c1 problems
Post by: Eddy6120 on February 21, 2015, 07:25:14 pm

Thank you so much, I will look into those right away.. I love reading books on tube amps, but not very knowledgeable in finding the problem in them. Yes, it is a PCBoard, I try to stay away from products made in China, but got a good deal on this.. This is actually my "backup" amp, my other one is a 67' Fender Deluxe Reverb..I play in church & in the winter I like to leave the Vox there, so I don't have to lug my Fender every Sunday through the cold & snow (She's my baby) Thanx Again Guys, much appreciated!!       

Title: Re: Vox AC15c1 problems
Post by: EL34 on February 22, 2015, 06:10:15 am

Use a wooden chopstick to poke and press on the board with the amp on.



See if you can find a broken solder joint or loose connection

Title: Re: Vox AC15c1 problems
Post by: Eddy6120 on February 22, 2015, 04:54:42 pm

Will do, sounds like a good (& safe) way to check it out. Thanx!