AD633 Ring mod

[Tim Ressel]

Keith,

The trimmers on pins 2 & 4 seem to be offset adjustments. They are meant to eek
out some precision when the IC is used as a multiplier. The Ad633 app note shows
these pins grounded unless offset trim is required, so you can toss them. Note,
however, that if you use a control voltage as one of the inputs, the offset
adjustment might be handy.

Tim Ressel--Hardware DQ
Hewlett-Packard
Verifone Division
916-630-2541  
tim_r1 at verifone.com                     



> ----------
> From: 	keithw at cix.compulink.co.uk[SMTP:keithw at cix.compulink.co.uk]
> Reply To: 	keithw at cix.compulink.co.uk
> Sent: 	Wednesday, December 22, 1999 3:55 PM
> To: 	synth-diy at mailhost.bpa.nl
> Subject: 	AD633 Ring mod
> 
> Hi all and a merry christmas to each and every one of us!
> 
> Right, I built a couple of the AD633 ring mods from a schem from 
> synthfool? ..the really simple schem floating round the ether, they
> seem to work ok but somrthing bothers me, the 100k trimmers
> seem to have little effect? A friend also built one in to a 2600 and has
> the same feelings about it. Has any one detected any mistakes
> in this schem? I am a bit dubious about the 100k resistor going
> in to pin four of the 633 myself...any thoughts anyone??
> 
> cheers and mince pies..
> 
> Keith Winstanley
> http://home.freeuk.net/lowpass
>