MOTM

New pictures show the final cabinet atop the others.  The eight 2U blank 
panels are all the space that's left.  Go here and scroll to the middle 
of the page:

http://www.pugix.com/overview.htm

New recordings of a big drone patch I've been playing around with.  At 
the top is another picture of the big drone patch, in which the new 
cabinet shows a little.  Scroll to the bottom for the MP3's.

http://www.pugix.com/music-samples.htm

I have moved modules around quite a bit.  (Now why did I make my website 
have pages corresponding to the cabinets?!)  I hope to find time to take 
more, and better, pictures of each module.

Richard Brewster
http://www.pugix.com

Great pictures and sounds, that's a nice synth you've got there.

But I'm wondering how you reach the top cabinet controls, are you 7 
foot tall? A long time ago I was discussing with Larry the practical 
size of a synth. Four rows seemed to be about the upper limit if you 
have it placed on a table top with keyboard in front. In my case, I 
expanded downwards with no keyboard in front so that I can have 6 
rows within reach. How are you managing with 5 rows on a table top?

Definately an amazing rig se\ufffdor!  Lots of "synth porn"
to peruse for sure!  Question: Do you possibly have
any sound samples, or know of any samples online of
those Bi-N-Tic filters, and also the Wave Multiplier? 
Those are kinda on the top of my wishlist right now
for when I get my Christmas bonus here at work:)


 
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Thanks, Scott.  I work standing up.  I'm a little under six feet tall 
and I have long arms.  I can reach the highest pots in the top cabinet 
without stretching.  I do not plan to put modules with jacks high up on 
the panel into the top cabinet!  Note that the keyboard sits at the same 
level as the bottom cabinet.  If I raised everything up with a hutch 
like the dot com 'keyboard garage':

http://www.synthesizers.com/cabinets.html#qcskg

I would have a problem reaching the top.  But I don't plan on doing that.

Richard Brewster
http://www.pugix.com

Scott Juskiw wrote:

> Great pictures and sounds, that's a nice synth you've got there.
>
> But I'm wondering how you reach the top cabinet controls, are you 7 
> foot tall? A long time ago I was discussing with Larry the practical 
> size of a synth. Four rows seemed to be about the upper limit if you 
> have it placed on a table top with keyboard in front. In my case, I 
> expanded downwards with no keyboard in front so that I can have 6 
> rows within reach. How are you managing with 5 rows on a table top?
>
>
>  
> Yahoo! Groups Links
>
>
>
>
>

If you are not already on the CGS email list, you can sign up here.

http://launch.groups.yahoo.com/group/cgs_synth/

There are some Bi-N-Tic filter examples in the files section.  Both it 
and the Wave Multiplier are wonderful modulators.  One of the voices in 
the Big Drone patch uses the Wave Multiplier.  It makes fantastic 
harmonics.  Both of these are worth doing if you DIY.  I would like to 
provide more sound samples for the unusual modules in my synthesizer, 
and I hope to get around to it.

-Richard Brewster
http://www.pugix.com

timothy cooper wrote:

> Definately an amazing rig se\ufffdor!  Lots of "synth porn"
> to peruse for sure!  Question: Do you possibly have
> any sound samples, or know of any samples online of
> those Bi-N-Tic filters, and also the Wave Multiplier? 
> Those are kinda on the top of my wishlist right now
> for when I get my Christmas bonus here at work:)
>
>
>

I got around to updating my website today.  I added the long promised 
Wogglebug project page with full schematics and pictures, plus the three 
latest modules:  Blacet StonZ Phaser, Oakley Superladder VCF, and CGS 
Tube VCA / Timbre Modulator.  And a picture of the back of my CGS 
Digital module, which has 8 circuit boards.  I took a new photo of the 
MOTM-650, too.

No, I'm not done, yet!  I am waiting for more MOTM to be announced.

http://www.pugix.com

Be sure to refresh your browser cache.

-Richard Brewster

I'm very curious about the pentode VCA.  It looks like a very promising
module for a number of reasons.

http://www.cgs.synth.net/modules/cgs27_tube.html

The parts are inexpensive and the design seems relatively simple.  In
fact, I'm thinking it would take less time and money to build than an
OTA-based design.  Perhaps more importantly, it only uses +15V for
the plate voltage, so it does not require a separate power supply and
it is relatively safe for DIY.

The use of +15 plate voltages with pentodes also opens up the
possibility of other voltage-controlled modules using tubes such as
filters and waveshapers.

How well does it work??  Do you have any examples how it sounds?
While cut-off tubes are used in compressors, I was under the
impression they didn't work well as gates. Did you have to bias the
control voltage??  Did you connect the suppression grid to the
cathode??

Did you use a PCB from CGS??  There appears to be two, a CSG65 and a
CSG27.   What did you use to supply the heater voltage??  I'm
thinking a dual module using 6064 tubes would draw around 600mA,
which would be about 75% of an MOTM-900. Then there is the other CGS
tube VCA, that uses a tube that only draws 13mA:

http://www.cgs.synth.net/modules/cgs65_vca.html

Unfortunately, I am totally unfamiliar with the 1J24B /1J24B  and I
cannot seem to find anything about it online written in English.

I'm not familiar with directly-heated cathodes, so I'm a bit confused
what pin 3 does, and the heater circuit shown in the CGS65 schematic.
It also looks like the suppression grid is connected to the negative
rail??

Thanks for the update.  Your consideration is appreciated.

On 3/4/07, Richard Brewster put forth:

>I got around to updating my website today.  I added the long promised
>Wogglebug project page with full schematics and pictures, plus the three
>latest modules:  Blacet StonZ Phaser, Oakley Superladder VCF, and CGS
>Tube VCA / Timbre Modulator.  And a picture of the back of my CGS
>Digital module, which has 8 circuit boards.  I took a new photo of the
>MOTM-650, too.
>
>No, I'm not done, yet!  I am waiting for more MOTM to be announced.
>
>http://www.pugix.com
>
>Be sure to refresh your browser cache.
>
>-Richard Brewster

I built two of the CGS65 VCA / Timbre Modulator. To quote Ken Stone:

The tube chosen is the Russian sub-miniature 1J24B (1SH24B, 1\u041624\u0411). It 
operates on low voltage, and uses a mere 13ma at 1.2 volts for its 
heater. In other words, the heater uses less power than the average LED.

For more information, post to the cgs_synth Yahoo group.

I plan soon to create sound samples from all of the more esoteric 
modules in my synth, including this VCA. I classify it as a Timbre 
Modulator. While it is also a VCA, it's tweaked towards distortion for 
input levels above about 2V p-p. As the level increases, a triangle wave 
input morphs into a type of pulse wave with quite pleasing harmonics. 
Using an envelope to make this dynamic produces musical results.

-Richard Brewster
http://www.pugix.com

Mark wrote:

> I'm very curious about the pentode VCA.  It looks like a very promising
> module for a number of reasons.
>
> http://www.cgs.synth.net/modules/cgs27_tube.html
>
> The parts are inexpensive and the design seems relatively simple.  In
> fact, I'm thinking it would take less time and money to build than an
> OTA-based design.  Perhaps more importantly, it only uses +15V for
> the plate voltage, so it does not require a separate power supply and
> it is relatively safe for DIY.
>
> The use of +15 plate voltages with pentodes also opens up the
> possibility of other voltage-controlled modules using tubes such as
> filters and waveshapers.
>
> How well does it work??  Do you have any examples how it sounds?
> While cut-off tubes are used in compressors, I was under the
> impression they didn't work well as gates. Did you have to bias the
> control voltage??  Did you connect the suppression grid to the
> cathode??
>
> Did you use a PCB from CGS??  There appears to be two, a CSG65 and a
> CSG27.   What did you use to supply the heater voltage??  I'm
> thinking a dual module using 6064 tubes would draw around 600mA,
> which would be about 75% of an MOTM-900. Then there is the other CGS
> tube VCA, that uses a tube that only draws 13mA:
>
> http://www.cgs.synth.net/modules/cgs65_vca.html
>
> Unfortunately, I am totally unfamiliar with the 1J24B /1J24B  and I
> cannot seem to find anything about it online written in English.
>
> I'm not familiar with directly-heated cathodes, so I'm a bit confused
> what pin 3 does, and the heater circuit shown in the CGS65 schematic.
> It also looks like the suppression grid is connected to the negative
> rail??
>
> Thanks for the update.  Your consideration is appreciated.
>
> On 3/4/07, Richard Brewster put forth:
>   
>> I got around to updating my website today.  I added the long promised
>> Wogglebug project page with full schematics and pictures, plus the three
>> latest modules:  Blacet StonZ Phaser, Oakley Superladder VCF, and CGS
>> Tube VCA / Timbre Modulator.  And a picture of the back of my CGS
>> Digital module, which has 8 circuit boards.  I took a new photo of the
>> MOTM-650, too.
>>
>> No, I'm not done, yet!  I am waiting for more MOTM to be announced.
>>
>> http://www.pugix.com
>>
>> Be sure to refresh your browser cache.
>>
>> -Richard Brewster
>>     
>
>
>
>  
> Yahoo! Groups Links
>
>
>
>
>

On 3/5/07, Richard Brewster put forth:
>I built two of the CGS65 VCA / Timbre Modulator.

OK :)

>For more information, post to the cgs_synth Yahoo group.

While that's a good idea, I'm not on that list.  I asked you about it
here because you actually built one, and DIY modules in MOTM format
seem to be one of the subjects of this list.

>I plan soon to create sound samples from all of the more esoteric
>modules in my synth, including this VCA.

I would be interested in hearing that.

>I classify it as a Timbre Modulator. While it is also a VCA, it's
>tweaked towards distortion for input levels above about 2V p-p. As
>the level increases, a triangle wave input morphs into a type of
>pulse wave with quite pleasing harmonics. Using an envelope to make
>this dynamic produces musical results.

That makes sense, although I am also interested in how well it works
as a VCA.  Which is perhaps why I asked a bunch of technical questions about
bias voltages and suppression grids :)

Thanks again for your input.