Hello guys,

I'm getting a '70s Electro-Harmonix Deluxe Electric Mistress which isn't functioning properly anymore for cheap. I'm pretty sure it's the switch so I'm gonna change that out, and I want to make it true bypass while I'm at it. And maybe get some other mods done but I can't find any documentation on it.

Any of you guys have any article or something about modding or restoring a Deluxe Electric Mistress?
There's a scheme.

Basically, a flanger combines a very short time delay with the original signal.

What don't you like about the pedal? There's no point of modding for the sake of modding. As far as restoring the pedal, I'd suggest joining a DIY pedal forum of some type, and requesting some voltages of the ICs and certain points in the circuit.

Here's a pic

It's not in a very good state. The direct out isn't working, any idea how to solve that? The switch isn't 100% anymore so I'm changing that. I've already got a DPDT switch so I could make it true bypass too, if end_citizen could help?

About mods, there's a slight volume drop I'd like to solve and if possible I'd like to remove the power cord and just install a Boss-type jack so it can be used with an adaptor.
Quote by blandguitar

What don't you like about the pedal? There's no point of modding for the sake of modding.

This exactly.

Modding just for the sake of modding is a horrible idea with such a nice pedal.
To true-bypass it, just look up input grounded bypass, it should more than suffice.

There is a gain trim, adjust that so that there is no volume drop or to taste, true-bypass won't remove the volume drop.

It runs off of 15 volts, so unless you run all of your pedals at 12-15 volts, I'd leave it as is, some ICs don't really shine until 12-15 volts, and certain time delay chips are included. I'm not familiar with that specific chip, but if you've got space to put one wall adapter, I'd assume you could use a second for it, the draw will be negligible from outlet, best bet would be to leave as is, at least until you've got it up and running and working.

I don't see the extra jacks and direct out on that scheme, so I'm of no help on that front atm.


The D-Out is just a clean out, unless you're going to use it, don't bother, especially if you're true-bypassing.
Last edited by blandguitar at Sep 9, 2010,
Right thanks. So that only leaves swapping the switch and make it true bypass. Couldn't the direct out be restored by just connecting it to the input? Or would that cause buzz or noise?
The way it's made, it's just connected to the input, if you're doing this TB, if you want the D-out to not be used when bypassed, connect it to the effect input. If you want it to be available whether it's bypassed or not, connect it to the input jack.