[sdiy] Simple VCO: 4069 or 7555

[gavin russom]

As per recent postings I just built a 7555 based vco from electronotes whic is extremely simple to build and in my opinion producues a lovely sawtooth wave, very rich and loud.  There is also an additional waveshaper option which is simple as well to get other waveforms,  In the original you can also tap off a short pulse at the output of the 7555 but I didn't find it usable in my case, haven't heard the 4069 version but there's my two cents, the 7555 vco took me just under a week for board layout, etching, mounting and troubleshooting!  So I'd reccomend it!
Gavin
-----Original Message-----
From: Dave Magnuson <resfreq at hoohahrecords.com>
Date: Thu, 15 Nov 2001 09:34:03 -0500
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] Simple VCO: 4069 or 7555


> Hi List,
> 
> After playing with my SH-101 for a while, my 7 year old daughter decided
> she wants a monosynth.  Err, umm, actually, after playing my SH-101, I
> decided I WANT IT BACK, so I'm building her a monosynth to keep her
> occupied so I can go steal it!
> 
> I have enough left over circuits here to build almost the entire project
> already (LFOs, EGs, VCFs, VCAs).  The only thing I'm lacking is a VCO.  I'd
> like to keep this VERY simple, and scalability isn't too important (I can
> build a better VCO later if it ever becomes an issue).  I'd like maybe 2 or
> 3 octaves of range, so I'm thinking of trying the 7555 or 4069 based VCOs
> that we've been discussing lately. 
> 
> What are people's opinions of the SOUND of these two oscillators?  I know
> Scott G has heard both for sure... anyone else want to say which design
> they think *sounds* better?  I'd prefer to build the VCO with the most
> "character".  I know this is a very subjective matter, but...
> 
> Thanks!!!
> 
> Dave Magnuson
> 
> Resonant Frequency:
> resfreq at hoohahrecords.com
> http://www.hoohahrecords.com/resfreq/index.html
> 

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