Vox AC30CC2 HELP NEEDED

[bkvance]

Hey guys,

I really need you help! I was playing my AC30 yesterday and all of a sudden the amp started humming and all sound was lost but then as I strummed the strings again a very crazy sound came out of it. It was like I had a distortion pedal hooked up and cranked up. I replaced all the tubes including the rectifier and still the same this a loud hum that swells and the sting noise is still there. Im lost at this point so please help me !!

Thanks,
Keith

[10thTx]

I am thinking that you have oscillation & blocking distortion. It can alternate
from no sound to ugly distortion to squealing. Usually from a bad tube & often the power tubes. Do you know for certain that the "replacement tubes are truly good?

Have you carefully/safely checked voltages?

Having said that, sometimes there is something wrong with the amp to cause a power tube to go bad. Which may be the case for you since you tried all new tubes.

Bad solder joint can be a culprit also. I usually chop stick the board and solder joints to find this. I use a non-conductive stick like a chopstick.

With respect, 10thttx

[Colossal]

Keith,

I have been in a number of AC30CC2s that needed work. Are you comfortable working on amps? Do you have a multimeter? If so, I would take voltages throughout the amp and mark up the schematic (see service manual PDF https://db.tt/MMWCizO5) and repost. Sounds to me like a bad solder joint or a blown part. The CC2 amps I was in were obviously of overseas origin and looked very fragile. Loose sockets, undersized parts. Not good for an amp running AC30 specs.

Also, once you get in the chassis, look around for smoked parts. Post photos if you think it would help. If you can service it yourself and want to take it on, great, but if not, take it for service.

[bkvance]

Thanks guys I will get into it further, I pulled the tubes out of my Liverpool so I know they are all in good working condition. I will start poking around for a loose joint.

Keith

[bkvance]

Amp back up and running, I ended up taking it to a friend who has more experience than me and he found a bad joint and repaired it. I thought I had found it and just needed his ok.

Thanks for the help guys,

Keith

[renshen1957]

Amp back up and running, I ended up taking it to a friend who has more experience than me and he found a bad joint and repaired it. I thought I had found it and just needed his ok.

Thanks for the help guys,

Keith

Hi Keith,

You might find this page of interest:

http://www.chambonino.com/work/vox/vox11.html

The gent says some nice things about the CC (Custom Classics) instead of Chinese CrXp.

Please be aware that the reviews for the earlier versions that are online (those that Harmony-Central hasn't purged) may have had something to do with the lead free solder (and yes cold solder joints).

Best regards,

Steve

[lovetone]

Hello Keith

If your happy working with the chassis out and live !! With the amp on, hum present no guitar plugged in, remove each 12AX7 one by one until the hum stops. With this method you will find the area of the circuit that has a problem my guess is it will be the phase splitter as it sound like am output stage fault.

These amps use low quality components, i have had the main smoothing capacitors fail on these before.

Good luck