[sdiy] VCA LM13600 circuit 2 - matched trannies ?

[Czech Martin]

Depends on what you are trying to do.

If you use it to amplifiy an audio signal, the exact shape
of the "Exponential" characteristic is absulutely unimportant.
You can even not hear it if it would be a piece-wise linear
approximation (very crude).

If you use it to scale a vibrato, it might be , but not really.
As long as it is steady, it doesn't harm.
The output offset is then the most critical thing.

Of course, if you amplify ciritcal control voltages, a simple
temperature compensation could be appropriate. Then some matching could perhaps
help. OTOH I would not use this chip for anything DC critical.

No, I think it does'nt matter at all for this vca.

m.c.

> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Linium
> Sent: Mittwoch, 14. Juli 2004 15:18
> To: Scott Bernardi; Synth-DIY list
> Subject: Re: [sdiy] VCA LM13600 circuit 2 - matched trannies ?
> 
> 
> On mercredi 14 Juillet 2004 14:03, Scott Bernardi wrote:
> > Ideally the BC560 pair should be matched, but it is not as 
> critical in a
> > VCA as it is in a VCO. LM13600 can be substituted in this 
> case because
> > the output darlington buffer is not being used (that's the 
> only place
> > where LM13600 and LM13700 differ).
> >
> 
> Thanks Scott !
> 
> Linium
>