ideas for a diy copy of the serge smooth/stepped

[widdly]

I've been thinking about how you could build a smooth/stepped generator type module.

My idea would be to use the VC Glide from Jim Patchell....
http://www.oldcrows.net/~patchell/archi ... 280_7.html

..it looks like it could be tuned for soemthing like 1v/oct response. This provides the IN socket, RATE and VC RATE controls and the VC RATE socket. I think this would need a buffer on the input. It only uses half a ca3280 it should be good for a smooth/stepped setup.

The signal in and the output of the VC Glide would be fed to a comparator. This would give a high output if the input signal is larger than the VC Glide output and a low if the VC Glide is larger the input. This would be wired to the CYCLE output. I think adding hysteris and tuning this section would be the tricky part.

The output of the VC Glide is fed to a sample and hold circuit. I'd go with the YASH lf398 circuit from rene's synths-r-us. http://www.uni-bonn.de/~uzs159/yash.png This can be either a Sample and Hold or a Track and Hold.

For the smooth generator it would be a track and hold, in which case the 470p cap is shorted out and the trig input is from the HOLD socket.

For the stepped generator, the trig input is from the SAMPLE socket. You could just add a switch to short the 470p and be able to select either smooth or stepped behaviour.

The COUPLE OUT socket would be a comparator wired to the both the outputs pf the smooth/stepped.

Whatcha' reckon?

[Neutron7]

I am not sure what the entire circuit does but last time i did sample and hold i just used LF198, it worked very well, with minimal external components.

http://www.national.com/ds/LF/LF198.pdf

[widdly]

I think the LF198 is pretty much the same as the LF398 I was thinking of using. Rene's YASH design uses the LF398 and has some extra circuitry to make sure it triggers from a wide range of sources.

I've never played with a smooth/stepped before so I'm guessing how it would work. The Lag and the S&H are pretty obvious. It's the cycle out and the v/oct I'm not to sure about. I guess I'll have to breadboard it and see how it goes.

[Luka]

isnt the wogglebug similar to SSG?
it uses LF398

[widdly]

It's probably closer to a toppobrillo sport modulator... http://www.toppobrillo.com/sportmodulator.html

The S&H part should be no problems since I've built a bunch of these and I know that circuit works. The 3280 vc lag I've never built so I'll try that first then add in the other sub-circuits last.

[Luka]

Sure but is that diy ?

Also check the fluctuating random voltages in the source of uncertainty.
It is so cool. Mine has step + smooth outs

[widdly]

I mentioned the Sports modulator since it is basically an SSM clone which is what I wanna do and the sports manual has a reasonable explanation of how it works and what it can be used for.

The wogglebug is cool and all but it's kinda a different beast to the SSM. The SSM doesn't have any noise sources or clocks built in like the wogglebug so it needs an external source like a noise or noise->VCO to work as a random CV generator.

[andrewF]

The SSM doesn't have any noise sources or clocks built in like the wogglebug so it needs an external source like a noise or noise->VCO to work as a random CV generator.

a SSG with a built-in noise source is called a Serge RVG (random voltage generator)
or co-incidentally (not really) a Plan B heisenberg generator

[chinard]

do you have any ideas yet on what to use for a comparitor?

I am interested in building one of these as well

on paper looks simple enough to fit on a protoboard

[widdly]

I'd just use an op-amp. Probably a TL072 which I use for pretty much everything. You could google op amp comparator to see how to wire. Also check out about adding hysteresis if you are getting fast toggling on the output.

I haven't breadboarded this yet. Just got a roland vp9000 to play with and haven't finished my serge panel etc.etc.

Let us know how you go.

[tesla]

I found the SSG schematic on the net some time ago,i built it and it works great,i will PM you the file this evening if you like.

[andrewF]

I found the SSG schematic on the net some time ago.

found the ssg?!?
link?

[chinard]

SAUCE PLZ!!!

[tesla]

andrewF, the link is long death now,i found it while searching in a filehost search engine,but i can send you the file if you want.

Chinard,i send you a PM right now.

[Hi5]

andrewF, the link is long death now,i found it while searching in a filehost search engine,but i can send you the file if you want.

Chinard,i send you a PM right now.

me too if possible

[djs]

i'd like to see the schematic too.. and would probably buy a board or two if someone makes one

[Luka]

Hey guys

Please refrain from distributing schems that are not in public domain unless you have permission from creator