[sdiy] OTA question

[Harry Bissell]

Hi Ian:

I'd try adding a resistor from the Gm bias input to V- to draw a tiny
amount of current away from your current source at all times.  I think maybe
the your passive implementaion always has a low impedance, and your current
source probably has a fairly high impedance at low bias currents.  Might take your
linearity to hell...

There is a similar resistor in the OTA MS-20 filter

H^) harry 



----- Original Message -----
From: Ian Fritz <ijfritz at comcast.net>
To: Oren Leavitt <obl64 at ix.netcom.com>
Cc: synth-diy <synth-diy at dropmix.xs4all.nl>
Sent: Sun, 29 Aug 2010 23:13:03 -0400 (EDT)
Subject: Re: [sdiy] OTA question

At 08:55 PM 8/29/2010, Oren Leavitt wrote:

>Interesting problem Ian - That wave shape you describe sounds like 
>something you'd get when you feed a little of the triangle wave back to a 
>control voltage input. i.e. self modulation. Something reaching the CV or 
>linear FM inputs?

Thanks, Oren.  Yes, I wondered about that too.  But I think that would most 
likely hapen at all frequencies.  Unless the feedback is via some leakage 
mechanism.  That possibility will take some more thought.

   Ian 

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva