MOTM

What an *awful* week!

1) Flooding (4 people died here in Ft. Worth, washed away trying to cross
flooded roads).

2) Daughter totaled her car (both airbags deployed, no personal damage, car is
toast)

3) Prom Weekend (since daughter has no car, DAD does high speed runs to cleaners
(twice)/hairdresser/florist/pictures in the park/forgot corsage/this morning I
found 5 strange people asleep on the floor, all clothed thankfully).

Let's just say MOTM was NOT in the forefront this week. But thankfully it's
OVER, tomorrow (maybe) I can get a loaner car and get back on track. Sigh.

This week I will update the order form and add the GX-1 VCF. I'm not going to
'announce' it until June 1, so get in line :)

PLEASE PLEASE PLEASE use the order form: if you send me an email it just gets
sucked into a black-hole inbasket :(

I was able to place all the parts for the MOTM-485 VCF on the pc board (tight
fit), the schematic capture is 100% done and all I need to do is edit the
netlist to make the layout program happy (about 2 hours of work). The layout
time is about 12 hours (not too bad). I plan to have the layout sent for test
bards in about 12 days.

I have restocked the kits to 100% order fulfillment EXCEPT the '440, '410 and
'850. These I will restock (in this order) as time permits. I also managed to
build 6 assembled modules while waiting for the insurance companies to call me
back :(

Paul S.

----- Original Message -----

From: Paul Schreiber <synth1@...>
This week I will update the order form and add the GX-1 VCF. I'm not going
to 'announce' it until June 1, so get in line :)

Paul, can you clarify this for us a little.  Does this mean we can place our
order once it appears on the order form, or that we have to wait until June
1 to place our orders?

Thanks
Larry

P.S.  Sorry about the week from hell.  But, since your daughter is AOK, life
is still good. :)

>
> Paul, can you clarify this for us a little.  Does this mean we can place our
> order once it appears on the order form,

Yes. The June 1 announcement is for AH, SDIY, etc. Shipping starts around July
10th. My goal is 6 weeks from 'official' announcement to shipping begins.
Instead of 2 years or whatever.

Paul S.

hello all,
can't wait for that little beauty (it's about time i got more of the black
stuff)
for those that didn't see, the Yamaha GX-1 in the VEMIA auction finally went
for \ufffd15,200 ($27k ???), i don't know who bought it, but their march royalty
statements must have been a lot better than most ( my own was for \ufffd18, even
though sales added up to \ufffd24)
i briefly had my hands on the service manual two weeks ago - beautiful -huge
pull out block diagrams that would have looked amazing in a frame (this from
someone who has an old yellow & black wax trax records mailer in a frame)

cheers
paul b
sheffield
uk

--- In motm@yahoogroups.com, "Paul Schreiber" <synth1@a...> wrote:

> This week I will update the order form and add the GX-1 VCF. I'm not
going to
> 'announce' it until June 1, so get in line :)
> 

What makes the GX-1 VCF unique? How does it compare to the CS-80
filter? (I thought that they were similar!)

>
> What makes the GX-1 VCF unique? How does it compare to the CS-80
> filter? (I thought that they were similar!)
>

Sounds completely different, due to completely different filter topology.
The CS-80 VCF is a "standard" OTA-based state-variable filter (2 of them
in parallel, in fact). The GX-1 VCF is a Sallen-Key "diode" filter (the
filter's cutoff frequency is changed by modulating matched currents in a
set of diodes).

Paul S.

I wrote this up a while back to describe the research I did on the GX-1 
filters:

http://www.cs80.com/gx1_vs_vs80.txt

  For some pictures:

http://www.cs80.com/ne_proj.html

Crow
/**/

On Tue, 4 May 2004, elle_webb wrote:

> What makes the GX-1 VCF unique? How does it compare to the CS-80
> filter? (I thought that they were similar!)

can we hear some audio samples from the gx-1?

kevin


--- In motm@yahoogroups.com, synth1@a... wrote:

> >
> > What makes the GX-1 VCF unique? How does it compare to the CS-80
> > filter? (I thought that they were similar!)
> >
> 
> Sounds completely different, due to completely different filter topology.
> The CS-80 VCF is a "standard" OTA-based state-variable filter (2 of them
> in parallel, in fact). The GX-1 VCF is a Sallen-Key "diode" filter (the
> filter's cutoff frequency is changed by modulating matched currents in a
> set of diodes).
> 
> Paul S.

--- In motm@yahoogroups.com, "supisuzoi" <son_of_zoggs@c...> wrote:
> can we hear some audio samples from the gx-1?
> 
> kevin
Aaron Copland's "Fanfare for the common man" in the ELP "version"in 
Works1 (Manticore)
Enrico (Sicily)

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
/**/

On Tue, 4 May 2004, edibennardo wrote:

> --- In motm@yahoogroups.com, "supisuzoi" <son_of_zoggs@c...> wrote:
> > can we hear some audio samples from the gx-1?
> > 
> > kevin
> Aaron Copland's "Fanfare for the common man" in the ELP "version"in 
> Works1 (Manticore)
> Enrico (Sicily)

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
> /**/

I think I showed this on the gifs: the GX-1 sine is summed into a 'tone
mixing buss' ahead of the filters, which means the sine goes through the
filters.  Of course, there aren't any harmonics in a sine to filter, but
there are amplitude/frequency changes.  The csvoice.gif shows a sine level
control with the note that the sine signal is mixed into the final VCA,
bypasing the filters.  So, yes, it is another difference that matters. ;)

Crow
/**/

On Tue, 4 May 2004 groovyshaman@... wrote:

> 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

I'm not especially versed in the Yamaha topology, but is the GX-1 something like the 
MOTM-420, in which two (in HP/LP mode) are required to simulate the Korg MS-20?

Chuck
Filtre Whore

--- In motm@yahoogroups.com, synth1@a... wrote:

> >
> > What makes the GX-1 VCF unique? How does it compare to the CS-80
> > filter? (I thought that they were similar!)
> >
> 
> Sounds completely different, due to completely different filter topology.
> The CS-80 VCF is a "standard" OTA-based state-variable filter (2 of them
> in parallel, in fact). The GX-1 VCF is a Sallen-Key "diode" filter (the
> filter's cutoff frequency is changed by modulating matched currents in a
> set of diodes).
> 
> Paul S.

I'm not seeing the item on the order page.  What's the model number?

- chris

On May 2, 2004, at 8:39 PM, Paul Schreiber wrote:

> PLEASE PLEASE PLEASE use the order form: if you send me an email it 
> just gets
>  sucked into a black-hole inbasket :(
>

> I'm not seeing the item on the order page.  What's the model number?

It's the MOTM-485. I'll add it this weekend and send out an email when
it's ready to go. Adding stuff to the forms is slow and a pain. There is
probably a slick whiz-bang "order form compiler" somewhere :(

Paul S.