Just bought an early 1980's ehx memory man

[jimmythegate]

Hi guys! I just picked up this memory man and I'm thinking there might possibly be some problems with it. It all seems to work fine but sounds a little off in a few ways. I cracked it open and the first thing I saw was this Chinese transformer, I was wondering if the rest looked ok and if the chinese transformer is the same specifications as the original? It has the original cts pots that suggest it was made sometime around 1983

The first problem is the feedback dial, only the first 40% is usable (when turned up to halfway and beyond it's unplayable). It's exactly like putting an acoustic guitar in front of a heavily distorted amp. The second issue is the pedal seems to drastically boost my volume whenever it's engaged and the 3rd is the Chorus sounds like it's broken, almost an out of phase sound there's no warble. I was wondering if any of these are common problems with this pedal? Seen a few people have the same issue re the chorus on this model but they found no solution. Cheers

https://ibb.co/M2YjjhG
https://ibb.co/MfxVPnY
https://ibb.co/9TWmbFc

[vigilante397]

First off, welcome to the forum

That transformer definitely looks like a replacement, but 15V secondary sounds right, I'm assuming it's fine. It sounds like a re-biasing could help quite a bit. The feedback issue definitely sounds like a biasing thing, and I'm not positive on the chorus but it could help. I say re-bias it and see where that gets you, and if there are still issues we can go from there.

As for the colume boost, I've only ever dealt with the Deluxe Memory Man which has a level conrol on top to make sure that doesn't happen. Does the regular Memory Man have an internal gain trimmer for setting the output level?

[j_flanders]

Here's the schematic:
(a bit blurry but the best I got)

[Scruffie]

That schematic is for the reissue, it wont exactly match up to your unit.

I'd start by just replacing all the electrolytic & tantalum caps, all the issues you mention could be tied to that and regardless it's just one less thing to worry about, it's already been worked on and they're nearly 40 years old, so....

[theehman]

That's a 220v transformer.  Is that appropriate for where you are located?

Also, 15vac won't cut it.  The pedal requires +/- 15vdc so you'll need something closer to 24vac.

[vigilante397]

The pedal requires +/- 15vdc so you'll need something closer to 24vac.

Isn't it just -15, no positive rail?

[theehman]

The pedal requires +/- 15vdc so you'll need something closer to 24vac.

Isn't it just -15, no positive rail?

No.  24vac was the typical secondary voltage for EH products back then.

[aron]

Well, the good news is that you have an awesome pedal! I mean, this is my secret weapon that I use all the time. I loved my first one until someone left it outside in the rain!!!!!
OH sorry, my secret weapon is the DELUXE memory man. Yours is still good.