vox AC30 troubles

[gusss]

I have a VOX AC 30 that i purchased new in December 07, so its still pretty much brand new. I was at a jam session just recently and all of the sudden the volume dropped out and then went back to normal which has never happened before. This happend 2 times durring the session. anyway i powered it up today to practice and its acting wierd. About every 30 seconds the speakers will make kind of a popping sound but not loud, just very low. It started to hiss and fuzz ecspecially when i move or tap it, and every once in a while it whill make a low noise that sounds kind of like feedback, but the guitar is not plugged in while any of this is happening. It plays normal except for these noises which i know are not normal. The amp is still under warranty, but i just want to know if its somthing small like a tube went bad or something like that, so i dont have to go thru the hassle of sending it in over something simple. Any advise would be greatly aprecciated.

[Uncle Pat]

Sounds pretty tube-related to me.

[Griz]

Originally Posted by Uncle Pat

Sounds pretty tube-related to me.

+1 That would be the first thing to check.

AC30's have lots of tubes, and just about any of them can give trouble such as you describe. Try a visual inpection first to see if any of the tubes look odd when powered up. Check with a tech re: what to look for.

You could also try gently tapping them first (with the amp running - so be careful, and use a chopstick not your fingers; one hand behind your back).

Best of luck!

[Uncle Pat]

The noise description sounds exactly like what I was hearing from my Hayseed 30. Just had swapped out some microphonic tubes, and I was mystified.
Pulled the chassis and sent it to Rob.
He replaced two tubes....done.


Tube amps...I love 'em but they make me crazy.

[mcdes]

ha, another one, i learnt the hard way, replace all the tubes as soon as you get a new vox amp and you should be problem free.

the tubes they come with are mostly badm but have also taken a battering during the tedious journey to your hands.

pretty common really

[hamfist]

Yep tubes ! Sounds suspiciously like the rectifier tube to me although, in reality, could be any of them.

[dave s]

Originally Posted by mcdes

ha, another one, i learnt the hard way, replace all the tubes as soon as you get a new vox amp and you should be problem free.

the tubes they come with are mostly badm but have also taken a battering during the tedious journey to your hands.

pretty common really

Sadly, he speaketh the truth. Bite the bullet. Buy a full complement of tubes for the amp, install them and be done with it. Then, you can enjoy the new VOX amp.

dave

[gusss]

Thanks everyone for all the help you saved me alot of hassle. Any particular brand that will get me as close to the factory tone as possible cause i love the way my amp sounds now, and dont want to mess with that.

[Rod]

If it's a CC, the "Wharfedale" speakers on my friends AC30 CC had some problems...the wire from the terminals to the speaker were touching the metal basket, and shorting the amp out..check these wires, or plug into another cab, and see if the problem goes away...

[thudle]

Could be rectifier and/or your preamp tubes. Just change the preamps to Tung Sol's and the Rectifier to a JJ.

[mcdes]

Originally Posted by thudle

Could be rectifier and/or your preamp tubes. Just change the preamps to Tung Sol's and the Rectifier to a JJ.

carefull! with these valves it is in danger of sounding better than the stock standard!

not what he wants! ha ha

ditto nonetheless on valve choice

[Miles]

Probably a tube problem, but I still get the heebie jeebies from the chinese voxes. Plus, the fact that the el84s in ac30s get SO damn hot.

Probably no biggie though.

I used to get JJs, but I actually found them to be REALLY inconsistent from reliability, so I stick with Mesa tubes, actually. Yeah, they're Russian, but they work.