Amps cutting in and out

[inhuman666]

Both my Ampeg VH140C and Crate GX130C are experiencing the same issue. While playing thru them the volume dies out then comes back up again. I have tried another amp and guitar with the same cabinet and cables, to rule these out.

Can someone point me in the right direction. I do not know any techs in my country who can assist.

Thanks.

 

[petee]

I have this issue with my VH140C and I took it apart to troubleshoot it. Here is how I fixed it.
On the backside there is a preamp out and a power amp in, for both the left and right side. One of those 4 jacks is likely the problem, there is easy two ways to deal with it.
1. Take a cable plug and run it in and out of each jack multiple times, this will help to restore continuity through the switch on the jack that should be closed when there isn't a cable in it. You will likely have to do this every once in a while though.
2. Get a short cable and just jump the preamp out to the poweramp in and just leave it. This essentially does what the jack switch should be doing. This is a better fix.

There is another solution, but its expensive and unnecessary. Bring it in and have new jacks installed.

 

[psychodave]

Since it’s happening to both amps, I’d check the plugs and outlets. Then all cables.

 

[inhuman666]

Since it’s happening to both amps, I’d check the plugs and outlets. Then all cables.

I did try a third amp using the same outlets, cables and cabinet....with no issues.

 

[snowdog]

could be a cold solder joint. they are hard to find