Cgs synth

I think I preferred the LM358 for the Grinder, as recommended by Ken.
Dang, it has been too long ago. Truth is that I assembled the board and
ran it on my bench, but I still have to build it into its Stooge panel.
I've had several months hiatus on module building due to moving to
another house. But I am about to start catching up, especially now that
I have a new cabinet, the double high slant cabinet from synthesizers.com.

-Richard

Adam Schabtach wrote:

>Thanks for the summary, Richard. I did find some of your postings in the
>archives. I think that you mentioned that you were going to try other ICs
>also. Did you ever do that experiment? Was there anything to be gained by
>changing op-amps?
>
>Thanks--
>--Adam
>
>
>
>>-----Original Message-----
>>From: Richard Brewster [mailto:pugix@...]
>>Sent: Saturday, May 07, 2005 10:42 AM
>>To: cgs_synth@yahoogroups.com
>>Subject: Re: [cgs_synth] Re: My first CGS module up and running
>>
>>I made the following small mods to my Wave Multiplier:
>>
>>1. Added a 100pf cap between pins 1 and 2 of IC1 (Grinder) to prevent
>>parasitic oscillation.
>>
>>2. Added a 1K resistor to ground at the Grinder output to cut the
>>amplitude in half. It can swing to +/- 14.5V otherwise. This mod
>>limits the maximum swing to about +/-7V. You might use two 2K resistors
>>here to reduce current consumption.
>>
>>3. Changed to a 33K resistor (from 100K) on the Folds CV input (I have a
>>pot on this input) for increased sensitivity.
>>
>>4. Changed to a 100K resistor (from 47K) between pins 1 and 2 on IC4 (I
>>have a pot on the PWM input) for increased sensitivity.
>>
>>5. Changed the pulse output (IC4 pin 7) to use a series 3K3 to 1K8 to
>>ground, as on the CGS56 board, to limit the output to +/-5V.
>>
>>Be sure to check the archives for information about tweaks to the
>>Steiner filter. I seem to recall posting my method for matching the
>>transistors, which is a good idea.
>>
>>-Richard Brewster
>>
>>
>>