EH Deluxe Memory Man Trim Pots?????

Started by themeanreds, February 07, 2007, 05:04:35 PM

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themeanreds

Hi y'all

I just got a Deluxe Memory Man which is not working. The previous owner opened it up and monkeyed with the internal trim pots (to increase delay time, I imagine), and now all the pedal does is make squealing, whirring noises akin to an old-timey radio being tuned.

Does anyone know how I can remedy this?

Thanks!

rockgardenlove




themeanreds

Quote from: rockgardenlove on February 07, 2007, 05:47:38 PM
Mess with the trimmers again?

naw; not that dumb. Just dumb enough to knowingly buy a messed-with DMM thinking that it would be an easy, intuitive fix.

zarathustra

Which version of the Memory Man is it?

I think you're going to have to mess with those trimpots, not only to get your delayed signal back, but also to reduce that clock whine you're hearing. I recently bought an old Memory Man with the same symptoms as yours, and I was able to get it in working order by using an audio probe to set the trimpots. It doesn't sound great yet -- still needs more tweaking (and probably a scope) -- but hey, at least it works.

Rafa

Is there any memory man project like the ones from tonepad, I mean with PCB layout. The only thing Ive found is the schematic

searoad

u can try to set all 5 trimpots to midpoint.
and follow this article http://www.diystompboxes.com/smfforum/index.php?topic=4050.msg23285#msg23285
Jenz explained what use are those trimposts and how to set them correctly.

boyersdad

After months of not being able to find suggested trimmer values or a schematic on my original MM, I said to hell with it, and went at messing with 'em one by one. Couldn't get any worse than not working right?

First  I eliminated the chance that one (or more) of the SAD1024's were bad by trying them one by one in a flanger I have that uses the same delay chip.

After they all checked out  I started with what I guessed to be the bias pot on the (again what I guessed to be) the first SAD1024 and brought it all the way down, then all the way up. Each pot I would turn, I would get a bit of "air" in a certian spot, so once I heard that, I'd leave it and move to the next pot, and before I knew it, there was some terrible and whiny delay! Then a few tweaks to smooth it out, and kablamo! Working. Took about 20 minutes total.

I'd still really like to scope it to make sure my DC balance is correct, and all, but it's working and sounds fantastic, if not slightly noisy, but hey, that's why we buy these things anyway right?  ;)
I like amps etc.

themeanreds

Quote from: searoad on February 08, 2007, 01:39:55 PM
u can try to set all 5 trimpots to midpoint.
and follow this article http://www.diystompboxes.com/smfforum/index.php?topic=4050.msg23285#msg23285
Jenz explained what use are those trimposts and how to set them correctly.

Yeargh; I have neither scope nor a sine-wave low-frequency generator. All I have is a cheap-o multi-meter.

I tried adusting the trim-pots by ear; I got delay happening, but I can't get rid of the super-high-pitched whine that's always present.

I assume that the settings for at least some of the trim-pots are dependent on settings of others; this means it might take forever for me to happen upon the right combination of settings. Looks like this might be out of my league.

themeanreds

ALso: this is a recent DMM with MN3005s.