The mighty modular synth

Synth 1 of 2. This is my brother's synth, he bought most of it off the shelf although there IS some hand made stuff in there. 

This is "finished", although he is threatening to add another cabinet. ;-)

There is lovely elegance in the shaping of those wooden cheeks. One of my bug-bears about home-builds is they often look too home-made, when I was an apprentice the phrase "it looks like you made it" was used as a put-down to anyone who hadn't put any thought or care into the finished product. This criticism cannot be levelled at you - everything looks very nicely done sir. 

This is the latest pic of the modular. I'm building some case lighting using electroluminescent wire (look it up) - this is "voltage on." I had one module (which I didn't build) burn out as it'd been shipped to me with the cable on the wrong way around. Reversing polarity is not recommended at all in systems with 1/8W resistors in....

The case has two expanders top and bottom, the logo has gone, room for more modules, in this case, patch connectors. Another two row case will sit on the top of this.

And a link to the least exciting video on the internet - 
https://www.dropbox.com/s/qxv8u5bhzwwo8ga/2015-10-25%2014.25.04.mp4?dl=0

Me too - I even bought the book (which I still have somewhere):

...to a 17 year old fan of electronics and electronic music that was geek-porn back in 1974 (and I don't mean the two ladies bizarrely dressed in regency costume).

The sine wave can be sent down, for example, a length of telephone cable. Attach test equipment at the other end, eg. an oscilloscope. Do you see a sine wave at the other end or has it been altered - is there noise on the line ? Could be electromagnetic interference, etc. 

Also used to produce a tone which is even and can be used to test, say, recording studios or environments. Test generators generally died out in the late 60's. You may find a few lying around today.

An oscillator..... a VCO or "voltage controlled oscillator" -  is slightly more complicated. Here's one I built earlier - sounded very Blue Peter, then. ;-) This is a multi waveform oscillator. It can produce sine waves, but sine waves are very boring. So you can also select (via the jack sockets below) sawtooth, square, triangle - etc - waves. There's an octave knob above (the large white one) - set it to 32, very low note, 16, note an octave up.... etc. 9 octave range. And very accurate too, generally to about 2 cents. The numbers refer to lengths of organ pipe, believe it or not. 

So a test generator is a simple sound producer. An oscillator is usually better built, more accurate, multi waveform and designed to interface with filters, amplifiers et al. 

This works on having an input of +5 to -5 volts. Go up one volt, the pitch changes by one octave. "Control voltage" is what analogue synths work on, but all have different standards. Which is a bit of a headache and why I'll have the soldering iron out this afternoon, converting the output from a sequencer to one which my Korg synth expects to have as an input. 

If you have a look at Eurorack systems now, anyone can build (or buy, off the shelf) a modular. I decided to build my own as I had electronics as a hobby. You don't have to know much. I am no expert, I can tell you how an oscillator works but not, for example, how to put the waveshapers together. I'm just doing this to save money and for the pleasure of building it myself.

I can well believe that about the VCS3 !!!! You can still get them, y'know, EMS produce them for £1800 each. I was amazed to find out that Peter Zinovieff is still going.....

Moog has reissued the original 55 with original wiring. Want one ? $150,000. Synthesizers.com do a very good replica Moog system for a fifth the price. You can replicate the same system in Eurorack format for about $3-4,000. 

I always get people telling me that old Moogs sounded better due to the poor build quality. These people haven't got an idea what they're talking about, honestly. They simply don't. ;-)