Home › Forums › Help/Technical Questions › Need help with a Deluxe Memory Man
- This topic has 3 replies, 2 voices, and was last updated 15 years, 2 months ago by Stoner Wizard.
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May 18, 2009 at 2:52 pm #78254Stoner WizardParticipant
Hello everybody:
I own a pre-2.003 DMM reissue (a pointer-knob version), which was modded to True-Bypass (3PDT switching, thus, LED lights only when delay is engaged instead when power is on). This version, has the JRC4558 chips (if this gives you any add. info). Also, I replaced the internal transformer and AC cord with a socket for using the standard 24 volt/100 mA power supply.
It worked well the first times I used but last day, after a break, I played again and (I did nothing but bypassing the amp) it didn’t seem to work properly… so strange but this is what happened!
Here’s the problem: The DMM actually works but the output volume is dramatically low. In fact, even at max. level it still sounds lower than bypassed volume.
But, to my surprise, when I make it self-oscillate, the feedback loop reaches the usual “louder-than-hell” volume.
I mean, the delay works and sounds, all pots and switches go well, but the output level is almost unnoticeable.
Does anybody have any idea of what could happen to my DMM?
Thank you very much in advance.
Regards
Nacho
May 27, 2009 at 9:38 am #97042Stoner WizardParticipantHello again:
As I posted last day, I’m still “trapped” with the same problem. The past week, my guitar tech and me have been testing and checking values of chips, resistors, and any components of my DMM.
Looks like science fiction but, despite our efforts… the problem stands still.
The weird thing is that the effect sounds and pots interact when you tweak them. But the output level cannot reach the bypassed level, except for the self-oscillation feedbacks which goes over the top as usual when we make them.
Any idea of what could be wrong?.
I may take some photos if could serve as add. info.
At the present time, we’re working with my other two DMM’s which work OK (a 2003 “Pre-True Bypass version) and a 2.007 True Bypass version. We hope that comparing the circuitry and testing the sounds we can get the solution.
I’ll keep you updated for fresh news.
Thanks and regards from Spain.
Nacho
May 27, 2009 at 3:49 pm #97053julianModeratorHmmmm, I would think that perhaps a gain stage is malfunctioning, or that the mix pot is possibly bad.
June 2, 2009 at 7:32 pm #97257Stoner WizardParticipantHello:
Finally, we’ve solved the problem. It was a wire, which was in poor condition. So the solution has been cutting and re-wire again. Also, the incoming voltage was too much, so it has been adjusted in order to avoid future troubles.
But, the mystery continues: Yes!, when I set the delay time at shortest levels (from minimum to the mark located a 6 o’clock) I can hear a hum, but once i set the delay time knob past this value, the humming noise disappears. It’s a low frequency hum (similar in “tune” to a low G).
Also, when I made a self-oscillation, if I set the delay time from minimum to 6 o’clock mark, the oscillation doesn’t appear immediately. But if I begin to tweak with delay knob past 6 o’clock to longer delay settings, the oscillation goes OK.
The same trouble has my 2.003 Deluxe Memory Man.
I think this is a matter of “fine” adjusting, but does anybody have any suggestion or tip to start?
By the way, my 2007 Deluxe Memory Man doesn’t have this “problem”.
Thanks a lot.
Regards from Spain.
Nacho
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