Rickresource Rickenbacker Forum

I recently purchased an M14 A. After receiving it I put the tubes back in and turned it on. Power came on but no guitar -- only static and hum. Took the tubes out tried again same result. I plugged the same guitar with the same cord into a different amp and it worked fine.

So I took the amp to my local guitar store here in Saint Louis and they plugged in and the amp worked fine.

Brought it home and I got the same result as before -- no guitar, static and crackling noises as well.

Although the guitar and cord worked fine with a different amp, on a whim I switched cords and hooray the amp worked. It seems that the old tube amp doesn't like my expensive low noise cord with a gold-tipped jack plug. But the amp works just fine with a different (silver-tipped jack) and fairly cheap cord.

I'm trying to figure out why. Does anyone (calling all electrical engineers) have an explanation?

I'm not an electrical engineer, but put the tips of your two cords together side by side, and I'm guessing you'll find that they're not the same size...

Thanks but they are the exact same size. I know my initial post sounds -- well I'm sure it makes me sound pretty ignorant. But I can't figure out an explanation why the one cord will not work in the M14A but works in my other two amps.

You could compare resistances between cables if you have a meter.

Impedance cannot be measured statically, but you can at least make a comparison of resistance.