Serge Waveshaper schemos on Music Machines

Jim Johnson jamos at
Fri Jul 17 21:23:30 CEST 1998

Looks cool and easy to build. What are the logic and threshold levels in
this setup? And would this work equally well with a bipolar supply (I'd
like to set up +- 5v outputs on the logic section of my someday synth.)

Jim Johnson 
Metaphoric Software
Makers of Techno Toys
Software for Electronic Music
info at

*********** REPLY SEPARATOR ***********

On 7/17/98, at 3:03 PM, tomg  wrote: 

>On 16-Jul-98, Jim Johnson wrote:
>>4) Why use an LM3900 in this circuit, rather than a TL-074? 
>I used 39OOs to replicate the Serge Boolean Logic Module. This may or may
>be how Serge does it I don't know I've never used a Serge. It works
>Check it out.
>Maxx Boolean Logic BLG-1A
>The LM39OO "Norton" amplifier uses a inverted current mirror to achieve a
>non-inverted input instead of the normal differential input op-amp. This
>design allows the amplifiers to be run from a wide range (+4-36V) single
>supply solving most of the problems usually encountered running op-amps
from a
>single supply. The amplifiers of the 39OO can be overdriven and used in
>speed digital applications at more than +5V to supply more current than
>standard digital gates. Two inverters ,AND ,OR and XOR gates built around
>LM39OOs. May be combined to form NAND, NOR ect...

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