I spoke about doing this in my post on fixing up a Peavey VTM 120, but I didn’t take pictures. Well, after the ground pin fell out on my Ampeg V4-B, it was time to replace another power cord. This time, I took some pictures for anyone interested in taking on such a task.
This actually happened to me while on my last tour with Exhumed. It didn’t stop me from playing. A ground pin isn’t essential to a functioning amp. It’s a safety device, in case there’s a short within the amplifier, so the amp doesn’t conduct voltage into the user through the chassis. I took my chances on the road, but once I was home it was time to replace this safety feature.
I got a new power cord from Antique Electronic Supply, aka tubesandmore.com. I could have also cut down any number of left over the detachable IEC plugs like most modern amps use, but it’s nice to order a new 12′ long one for something like an amplifier that’s gonna be on stages with limited power supplies.
These older amps usually have hard-wired power supplies that feed into a cord-strain relief. It can seem difficult to get out, but it’s easy. Just cut the broken cord as close as you can to the strain relief.
Now you can pull out the individual hot, neutral, and ground wires with ease, until you can wiggle out the black housing.
Pretty soon, you’ll be able to free up the cord strain relief which slips right out. If it’s in good condition, siiiiiick, you can reuse it! If not, you’ll need to replace it with one of the same size.
I like to leave the wires soldered in and undo them one-by-one as I replace them, so I don’t have to question what goes where. Pretty soon, I have my new power plug in place and ready to be secured.
Now comes the annoying part. You have to get that cord strain relief back in place. It was difficult when I replaced the cord on the VTM 120, but on the V4-B, it was near fucking impossible. The new cord was a touch thicker and had less give than the old one.
With a lot of perseverance (and a little bit of filing) I was able to get the strain relief snapped in and the cord in place. Now my amp is ready to rock again and won’t send 450V ripping through my heart on accident.