Moog Music Forum

Long time lurker, first time poster... Hopefully you fine folks can help me out.

I'm having some troubles with my ring-mod. None of the parameter control jacks respond to expression pedal input. This happened out of the blue about a week ago. I bought it used, so it might just be everyday wear and tear but I'm not sure. All the knobs work fine, but the expression pedals do zilcho.

I rack-mounted it along with my MuRF and FreqBox not too long ago, with the MuRF in the middle. I've had to air-dust the MuRF a couple of times (audio out was shorting a bit and tap tempo would work), but dusting out the Ring Mod didn't have any effect.

Please help me out... I've got a gig next week and I really wanna sweep the frequency of a fat square wave on stage. Thanks.

Perhaps you have some ring-to-sleeve shorting in one of the jacks. If you plug a TS cable into any of the expression inputs, all expression inputs will be disabled. (I.e. you will not be able to use any expression pedals.)

Can you check if any jacks are shorted internally? Or use a non-expression source (e.g. an external LFO) to modulate some controls? If not, it may be more serious.

latigid on wrote:Perhaps you have some ring-to-sleeve shorting in one of the jacks. If you plug a TS cable into any of the expression inputs, all expression inputs will be disabled. (I.e. you will not be able to use any expression pedals.)

Can you check if any jacks are shorted internally? Or use a non-expression source (e.g. an external LFO) to modulate some controls? If not, it may be more serious.

I hadn't thought about that. What's the easiest way to check for shorts in the jacks? I'll try running an external LFO into it and see what that does. Thanks for your help.

The absolute EASIEST way to check for shorted jacks is to plug a TRS cable into an expression input and test for continuity (using a multimeter with continuity function) and putting one lead on the sleeve and another on the ring.

Voltor07 wrote:The absolute EASIEST way to check for shorted jacks is to plug a TRS cable into an expression input and test for continuity (using a multimeter with continuity function) and putting one lead on the sleeve and another on the ring.

You guys rock! Thanks so much.

You are quite welcome!

Turns out my problem wasn't the ring mod at all... It was the EP-2!

I have two of these fine fellows and one appears to have quit working entirely. Any advice on how to troubleshoot an EP-2?

I'm planning on opening the case and taking a gander inside this evening.