eh memory man

[fporfidio@optonline.net]

hi guys, i had a guy bring in a memory man complaining that the feedback doesn't "run away" like it used to....now i have not seen a schematic of this thing yet but i have seen a few threads on this thing that everybody is turning trim pots all over the place....now, provided this individual did NOT go in there and turn pots....doesn't that mean that something is failing or failed? the one thing i noticed as soon as i took the cover off was there are a lot of tantalum caps in there and we all know those don't age well at all. anybody have any starting points for restoring these things or for at least getting the regegneration back up..................thanks,.................Frank

[cjlectronics]

Hi Frank,

I've repaired many. I have a few questions:
1. What version do you have... 3 knobs, 5 knobs, etc...
2. What are the BBDs... SAD1024, MN300x, etc...
3. Does it delay at all, but just no "run away" feedback?

Typically a tweak of the Bias trimpot will give you the run away feedback but if something is wrong then that won't do it. Do you know how to set the knobs to get feedback? Does your customer know how to do that, as well?

CJ

[fporfidio@optonline.net]

hey CJ, yep it dalays it is the 5 knob one as far as chips , i'm not anywhere near it right now. being he brought it in saying it didn't do it ANYMORE i'm guessing he would know to turn the feedback pot all the way up. what i really have to try and find out is was he in there or not. if he wasn't , there's got to be a reason it just stopped regenerating as much as it used to. i'm mostly a console / pwr amp guy so any light you can shed on this would be much appreciated...............thanks, Frank

[cjlectronics]

The 5 knob version should be the deluxe memory man but EH made so many versions of the memory man it could be different than this schematic here

Check the obvious stuff... +/- supply voltage, noise on the supply voltage, etc.... I wrote a quick method to tweak the bias and balance pots for a BBD here. This will help rebias and balance the BBD if the owner messed with the trim pots. Feel free to PM me and I'd be glad to send you my email where I can help with more information.

CJ

[fporfidio@optonline.net]

hi CJ, thanks for the info. i'll be going in tonight so i'll check all the basics tonight and get back to you.........................Frank