RE: audio oscillator (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 29 Jun 2007 11:33:55 -0700
From: Jim Lux <jimlux@xxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: RE: audio oscillator (fwd)

At 07:34 AM 6/29/2007, you wrote:

>---------- Forwarded message ----------
>Date: Fri, 29 Jun 2007 10:34:27 -0400
>From: "Lau, Gary" <Gary.Lau@xxxxxx>
>To: Tesla list <tesla@xxxxxxxxxx>
>Subject: RE: audio oscillator (fwd)
>
>Wouldn't op-amp integrators result in triangle-waves?  Making sine waves
>is a bit trickier.

double integration gets pretty close, parabolic instead of linear.

The Exar part actually has a chain of RCs that gets very close to 
sinusoid (sub 1% THD, as I recall), and some of the HP function 
generators do the same.

Kind of depends what tuning range, etc. you need, which approach to 
use.  It's hard to beat a nice Wien bridge for low distortion, but it 
doesn't have wide tuning range.