Block diagram or description of analog abstract generators?

[glorocks]

ED-
I'm toying with a "console" of my own, although I am leaning towards a modular design. PM your email address to me and I'll send you the stuff I have.
You are free to share, as all of this stuff is either public domain or un-copyrighted work.

[dar303]

Great idea to put this info out there for us! All inspiration is welcome, i'm considering a sort of hybrid analog system with parts of it in hardware and some in MAX/MSP and/or Supercollider software. I want hands on knob twiddling plus connection to my existing modular synths (Serge and Buchla) and some save/recall, algorithmic stuff and data visualization that these open software systems are good at...it just takes a lot of time and money!

[glorocks]

OK- We are going to start posting some stuff you all will find interesting.
I am going to start uploading bits I am currently working on. Now, I use EAGLE for schematics and board layout.
I have no desire to learn a new layout editor, and I don't have the time or desire to scan and convert to pdf.
There is a free version of EAGLE available, so I suggest you get it. In the future, all of my schematics will be in EAGLE's .sch format.
J

[ekeefe]

Hello,

I would be happy to convert your EAGLE schematics and/or PCBs into PDFs if that helps.

ED

[dar303]

Anything new here?

[lasermaster1977]

Hi,

I'm interested in learning more about analog abstract generators but I find it hard to get any good info!
I have acess to a lot of really complex modular synths and would like to use them to generate something beyond lissajous patterns, oscilloscope-like audio modulated saw-sweeps and such.
I have tried to inserts VCA:s and ringmods in the signal chain to make some aspects controllable but most of it looks sort of the same! Ways to make more geometric shapes, squares and maybe pointy objects would be cool and also know more about the building blocks for making the image rotate and other semi-3D operations.

I have an old geometric correction card attached to a pair of really old scanner drivers, I have been thinking of putting proper potentiometers on it and make it a module in my abstract modular, what do you think about that?

Any veteran laserists want to educate a poor victim of the digital generation?

I started out w/open loop galvos and analog generation of images way back. The XR2206 is a great little sine/triangle/square wave or ramp generator chip that can be voltage controlled and has built-in AM inputs. The chip is still available as is the 8038. The key to nice results is quadrature signals for X1Y1, summations (or multiplications or both) of more than one harmonically related frequencies X2Y2 (using PPL techniques) for each axis in the bandpass of the galvo (open or closed loop) with a harmonically related ratio range of 10:1 for base signals and in the range between 100:1 for amplitude modulation. For G115 or G120PD galvos I used 45 hz as the low end and 450 hz for the high end. Great things happen when X1, Y1 signals plus X2,Y2 have 1:1, 1:2, 1:3, 1:4, 2:3, 3:5, 7:10 frequency ratios, further excitement happens when amplitude modulating X1, Y1 while not modulating X2,Y2 or visa-versa.

As someone alluded to earlier, low frequency square waves (30-90 hz) on open loop galvos produces some great ringing affects at sharp transitions in the signal, especially when one axis frequency was very slightly adrift from the other axis frequency.

Here are some old pics of the type of results that give rise to harmonic geometries using summation and modulation or simply summation as in the last photo.



I later applied what I had learned in to digitally controlling waveform generation via computer and married a combination of the two....but be certain of this....playing an "visual" analog frequency synthesizer in real-time to music is a blast.