[sdiy] ASM-1 VCO section update

[Magnus Danielson]

From: Tom May <tom at tommay.net>
Subject: Re: [sdiy] ASM-1 VCO section update
Date: 20 May 2001 12:54:06 -0700

> Magnus Danielson <cfmd at swipnet.se> writes:
> 
> > Dear fellow Synth-DIYian,
> > 
> > I've just uploaded an updated ASM-1 description where I tries to
> > describe in some greater detail what is happening in there in the
> > VCO. Not everything is being described in detail just yeat, but I'd
> > like some feedback of how you perceive the road I am testing out, if
> > you like the style of the description etc.
> 
> There's a note there that says:
> 
>    The sync input should be feed with a pulse wave and not a sawtooth
>    wave in order to operate properly. So, for propper sync operation,
>    do not feed it sawtooth (or other non-pulse waveforms)!
> 
> If you use a pulse, one edge of the pulse will cause a sync and the
> other edge will cause a delay in the reset if the VCO was about to be
> reset.  I found this noticeable and objectionable when the frequency
> of the VCO being synced was swept -- it would "catch" briefly when the
> frequency hit multiples of the other VCO's frequency.  Syncing from a
> sawtooth of the proper polarity might prevent this.

Hoy! Tony! Do you recall the discussion we had on sync over at Paul's?

Could THIS be the effect we where talking about?
The recap is that you said that a separate JFET for the sync sounded
better and cleaner than the common sync in the style of ASM-1 and
others. If feeding a friendlier waveform (sawtooth) or do signal
conditioning one might come into play.... possibly...

Cheers,
Magnus