[sdiy] eml 101 VCO: continuously from tri to sqr to saw

[ganesha]

Thanks, that's some really interesting information. If
you get the chance to measure it that would be really
interesting. I also didn't know that the 8va was the
saw 1 octave up
regards, kris
--- ニコラス・ケント <ndkent at optonline.net>
wrote:

> 
> On Apr 1, 2006, at 4:41 AM, ganesha wrote:
> 
> > Hi all,
> >
> > Probably a complete newbie question but I like the
> way
> > you can change the waveform continuously from tri
> to
> > square to saw on the eml 101 vco's. I would like
> to
> > use that on a vco module I'm building myself, but
> I
> > have a question about the schematic:
> > http://www.krinkel.be/sdiy/eml101.jpg
> >
> > What kind of potmeter is used because it seems to
> have
> > a connection in the middle where you can connect
> the
> > square waveform?
> >
> > regards, Kris
> >
> 
> That's what I've been asking about too the last
> couple days. Those  
> pots in general, not the circuit you are looking at
> in specific.
> 
> As a whole the EML uses a bunch of those pots in the
> synth. So  
> perhaps if "FA" is a really odd (or not)  taper
> maybe it was chosen  
> because they had a supply of them and could cut down
> on the number of  
> different parts? Sooner or later I'll try to measure
> one.
> 
> FWIW the "8va" in the schematic is actually a saw
> one octave up.  The  
> knob's legend draws the entire range of output as
>   tri -> "sloped square" ->square -> saw -> doubled
> saw
> so it has at least one weird transition you've not
> mentioned (the  
> last 3 waves)
> 
> So that brings to mind that perhaps a same-octave
> saw would do  
> something less desirable??
> 
> If you are really keeping track OSC 1 doesn't have
> any mixing scheme  
> and Osc 4 has a simpler tri to square option.
> 
> Further weirdness comes with the wave choices on the
> EML 100 (if  
> anyone is keeping score)
> cosine(?) -> square/cosine -> square
>   tri -> square/tri (not the "sloped square") ->
> square
> 
> Of course in your case what you get with simplicity
> is to me is  
> spoiled by not having CV control on any of this.
> 
> oh, and then the 100 (not the 101) gets their mixed
> multimode filter  
> output to go LP->BP->HP->BR->LP via a pot
> But I don't have the schematics to the 100 filter,
> and as usual no CV  
> control of that.
> The 101 does a simpler LP -> BP -> HP
> 
> P.S. you can get the entire 101 schematics off the
> EML yahoo group.  
> I've still not sourced a set of 100 schematics
> though I have some  
> pages marked "100 and early 101" apparently for
> servicing  
> transitional 101 units.
> 
> ndkent
> 



		
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