VOX AC30TB reissue voltage selector

[fullclip91]

My amp was working 100% before this.

Until I started mucking around with the voltage selector on the back of the amp.
I turned the voltage selector down.
My amp proceed to turn off and now it will not turn back on.

I am not sure what this may be? Would anyone here have any idea how I may go about fixing?

[Robert M. Martinelli]

Hi and welcome!

By turning the voltage selector down keeping the mains voltage the same you supplied the amp with a voltage greater than the amp's need. This causes the voltages at the PT secondary to increase, and the current flowing to increase as well.....you can hope that the mains fuse blew before the amp got permanent damage. Disconnect the mains cord, check the fuse for continuity and, if blown, replace with a new one with the same rating ( amps and speed, you will find an "F" for "fast blow", an "M" for "medium blow", and a "T" for "time lag" or "slow blow" ).

Before switching the amp back on make yourself sure the voltage selector is set correctly. If the fuse blows again, then something inside has probably suffered permanent damage.

Hope this helps

Best regards

Bob

P.S. - Just curious - why on earth did you feel the need to mess with the voltage selector if the amp was working properly?

[fullclip91]

Thank you very much

It made no sound and no smell so I hope no permanent damage was caused.

[Robert M. Martinelli]

I hope so,
anyway...be aware that the high voltages inside a tube amp can KILL you, so, should the amp show symptoms of a permanent damage, don't try to open it unless you know what you're doing....we can try to help you, but, being not there, we cannot save you if you do something wrong.....
Changing a fuse is quite straightforward and easy, safely servicing a tube amp is a wholly different matter.

HTH
Best regards
Bob

[fullclip91]

Yeah I was very stupid and did not know the consequences.
My dad had a look at it and the fuse is alright so I screwed my amp somehow.

He is taking a closer look tomorrow.. sigh
If there happened to be permanent damage to the amp? How much am I looking at to replace the parts?

[Enzo]

Anywhere from next to nothing all the way up to expensive. We have no way to tell without more information.

There is not a "the" fuse. The fuse you can see from the outside is just one of them. There are also at least four more inside, for various voltage supplies. You will have to remove the metal chassis from the wooden cabinet to have access.

ALWAYS work with the amp unplugged from the wall, and remember the voltages this amp runs on can KILL YOU.

[Robert M. Martinelli]

What Enzo said..

I told you to check the mains fuse because it was the first thing to do and also because by your words it seemed to me that you're not an expert, so I thought it was better for you to do this easy (and not dangerous) check first.

I hope nothing serious got damaged, let us know if we can be of some help, but be aware that, to be able to help, we need accurate info to work on, and, even if I said it before and Enzo rightfully repeated it already, I'd like to stress the concept that the voltages inside your amp can KILL a person quite easily...if in doubt, you'd better refer to a qualified tech.....there's no shame in admitting our limits if this can save a life....

Hope this helps

Best regards

Bob