Hey Crow, does the GX-1 also have the sine going straight to the VCA that
the CS has? If not, that would obviously change it's bass character from
the CS and therefore further complicate the filter comparison.
George
----- Original Message -----
From: "The Old Crow" <oldcrow@...>
To: <motm@yahoogroups.com>
Sent: Tuesday, May 04, 2004 7:47 PM
Subject: Re: [motm] Re: Update/GX-1 VCF info
>
> Another thing to note about the sound of the GX1 voice vs. the CS voice
> is the VCO normalization:
>
> http://www.cs80.com/gx1voice.gif
>
> http://www.cs80.com/csvoice.gif
>
> The GX1 VCO routing is just slightly more complex. ;) The thing to
note
> here is that the MOTM "GX-1 filter(s)" are described in gx1voice.gif by
> the text "to Sallen-Key HPVCF, LPVCF and final VCA." The BPF and HPF
> shown as harmonic selectors for the sawtooth and variable pulse
waveforms,
> while being the same design as the VCHPF and VCLPF, aren't in the CS
voice
> at all, so a comparison of the GX1 S-K and CS-80 SVF filter models
really
> doesn't quite work out if the VCOs driving them are different. (Though
> even if the CS VCO normalization is the simpler one vs. the GX1 VCO, the
> CS VCO ∗chip∗ is more complicated then GX VCO discrete module...more on
> those projects some other time.)
>
> If anyone read my notes on cracking open the NE filter modules, it
> becomes apparent that the popular myth that CS-80 voice = chipped
version
> of GX-1 voice isn't true. What is correct is that both used 'dual
layered
> voicing,' where each voice is actually two voice circuits operating in
> parallel, up to a total of eight sounding at once (16 voice circuits in
an
> 8x2 fashion). For the GX1, this is the case for the both upper and
lower
> manuals. The solo manual is a single, unlayered voice, and the
pedalboard
> is a triple-layered voice. The CS-80 has of course one manual operating
a
> dual-layer voice.
>
> I guess the important thing to note here is that using something like
an
> MOTM-310 driving two MOTM-485 GX1 filters or a single MOTM-480 filter
will
> obtain different tonalities. The 480 is (in my opinion) more silky /
> sibilant whereas the 485 is more brassy. Both provide that unmistakable
> Yamaha ensemble strings/brass sound, however.
>
> Crow
> /∗∗/