Echoplex EP2 Hum

[christianichter]

Running into some problems with my EP2, and I'm not very knowledgeable when it comes to this stuff...

When I'm running the signal without delay, it sounds great. But as soon as I turn the "Volume" knob up, I get this terrible hum that makes the Echoplex simply unusable. The "Volume" knob blends the dry (unaffected) signal with the wet (delayed) signal. So the more you turn the knob, the more the delayed signal is mixed in.

Anyone have any ideas?

[Enzo]

Broken ground to playback head?

[christianichter]

I'm sorry I'm so ignorant... What does the ground wire look like? How can I tell where the problem is?

[52 Bill]

The EP-2 has two tape heads, one that is stationary (the Record/Erase Head) and one that moves along the delay adjust slider (the Playback Head).

Each of these heads is connected to the circuitry by a shielded cable, like a guitar cord. The shield is the outer braided sleeve that as the name implies shields the inner conductors from external noise sources.

Look at the back of each tape head. Any loose wires there? Pull the chassis out of the case and follow the wires that are connected to the back of the tape heads. Are there any loose wires where they connect to the circuitry?

Look at the back of the volume control for the delay signal. Are there any loose connections there?

[christianichter]

Thanks Bill,

That's what I've been looking for, but I can't find anything wrong. Any other ideas as to where the problem might be?

[52 Bill]

You need to isolate the problem.

You already know that the hum is only on the delayed signal, but is it on the playback or on the recording end? Plug a foot switch in and shut off the record function and see what happens. Is the hum any different?

Have you tried changing the tubes?