[sdiy] Op amp for saw core VCO

Ian Fritz ijfritz at comcast.net
Sun Oct 26 19:55:00 CET 2014

You don't want to skimp here.  You need low offset, hi impedance and hi 
speed.  The OPA 134 is what I use.  The OPA 602 is an even better device, 
but a bit of an overkill, IMO.  A TL074 gives noticably poorer 
performance.  My designs are here:


At 12:29 PM 10/26/2014, Tim Ressel wrote:
>So your standard sawtooth core VCO with the integrator and discharge FET. 
>I am re-designing an existing product that uses a CA3130 as the 
>integration amp and want to update it. What is a good modern amp for this 
>application? Or if you prefer, what kind of amp is needed here? Precision? 
>High speed? I have used an OP37 and an OPA602 with good results, but I am 
>hoping for an inexpensive alternative.
>Tim Ressel
>Circuit Abbey
>timr at circuitabbey.com
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl

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