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vintage EHX clone theory help

Posted: Mon Oct 22, 2012 7:19 pm
by space6oy
friend of mine brought a couple dead pedals over for me to take a look at this weekend. line 6 DL4 was no big deal, just needs a new power jack (guessing someone tried to force the wrong supply into it). vintage EHX clone theory though, this amateur has nothing on... it's from back when an AC line was permanently attached. bypassed it's fine. first time i plugged it in it was like its rate knob was adjusting a filter frequency (just how it sounded) without any animation. opened it up, took a look at its board, didn't see anything disconnected or visibly damaged, plugged it back in and now it's just acting like a very subtle, gritty distortion.

any of you pedal tech pros have any suggestions for me?

Re: vintage EHX clone theory help

Posted: Mon Oct 22, 2012 7:24 pm
by Scruffie
Voltages of all the pins in there and info on if this is a SAD1024 model or MN3007 version.

Filter frequency suggests for some reason the rate knob was acting to control the delay time and gritty distortion could be a misbiased BBD but can't go further without the above info, that's just guessing.

Re: vintage EHX clone theory help

Posted: Mon Oct 22, 2012 7:35 pm
by space6oy
it's the MN3007 version. has six 104M 100v capacitors.

Re: vintage EHX clone theory help

Posted: Mon Oct 22, 2012 7:47 pm
by Scruffie
Welp, request for voltages at all pins stand, that should help get to the bottom of the issue and tell me what's working and what isn't.

Re: vintage EHX clone theory help

Posted: Mon Oct 22, 2012 7:56 pm
by space6oy

Re: vintage EHX clone theory help

Posted: Tue May 28, 2013 7:50 pm
by pinkjimiphoton
does sound like a misbiased bbd. i have both versions, an original with the 1024 and a clone i built with the mn3007... if the bbd is off, you'll definitely get distortion.
did you ever get this thing up and running?

Re: vintage EHX clone theory help

Posted: Tue May 28, 2013 7:52 pm
by space6oy
no. it's still open on my workbench.

Re: vintage EHX clone theory help

Posted: Tue May 28, 2013 8:31 pm
by Scruffie
We dug further via PM, can't remember where we ended up though.

There was something wrong with the voltages though...

Re: vintage EHX clone theory help

Posted: Tue May 28, 2013 9:13 pm
by space6oy
i've forgotten too, think it was something to do with internal trimpots though...