broken efx

[gstopp at fibermux.com]

     There's a couple of things that could make the old BBD's sound 
     distorted:
     
     First, make sure that you're not overdriving the input. 
     Guitar-oriented floor toys tend to expect low-level inputs, and a 
     synth output could be too hot. If you are using a synth, turn its 
     output down to around "1" (or less!). Maybe you've already tried this.
     
     Second, BBD's like the SAD-1024 and MN300X have trimpots at their 
     input to adjust the bias voltage and at their output to adjust the 
     clock reject. If the bias trimpots are out of tweak then the signal at 
     the output can range from fine to distorted to totally dead. A scope 
     is best for tweaking these, but doing it by ear may get you by. Also 
     finding the right trimpot without a schematic may be tough. As always, 
     tweak at your own risk!
     
     Hope this helps,
     
     - Gene


______________________________ Reply Separator _________________________________
Subject: broken efx
Author:  moron5000 at juno.com (john miller) at ccrelayout
Date:    3/18/97 10:27 AM
     
The other two I have are Electro Harmonix Memory Man's , one's a PLUS and 
the other standard. The difference is one uses's SAD1024's and the other 
MN series BBD's. The problem with these is the delay seems kinda 
distorted on the output. I have tried adjusting the clock frequency but 
that seems to make it worse. If any one knows if there are schematics on 
the web for these or has any suggestions on how to trouble shoot let me 
know.