Wednesday, 30 June 2010

Another Video

video
feedback, live camera feed (black and white security cam found in a bin) and oscillators and mixing from the synth. the sync feed to the camera has been pulled which gives it the scrolling across the screen effect.

More VidSynth Pictures

heres a shot of the video synth as it is today - its leaning against the effects rack with the old modular synth on top.
the three modules running across the top of the cabinet are the oscillators. they are based on the venerable and much loathed XR8038 chip. i like it. the flux capacitor shaped module in the centre is a 3 channel arbitrary function generator and the one to the left is a 3 by 3 mixer matrix. heres a pic of the guts of one of the VCOs
a note about the jacks - they're not BNCs but frankly i dont care. it works. the hookup wire is RG178 super skinny video coax. pots and switches are surplus from somewhere or other, and the pcb is home made. note the extra capacitors tacked on the board for more power supply goodness. yay prototypes...

Video Demo

video
heres a short video - live input from a black and white camera, processed and mixed with some abstract video from the synth.

Prototyping

heres a shot of the synth that made the previous screenshots ..
its a large format modular synth that has been built over the last ten years. its mostly based on EFM circuits and CEM chip applications notes. the EFM modules are remarkably adept at working at frequencies far exceeding the audio bands... well, the ones that didnt explode due to user error are anyways...
the video encoding hardware is in a seperate rack that consists of various 99p ebay bargains - broadcast grade rgb to pal, component to pal and pal to everything encoders and decoders, 2 sync pulse generators, various genlocks, mixers, switchers, VDA's and an oscilloscope. ebay rocks.
its a great time to pick stuff like this up on ebay. all the pro broadcast facilities in the UK are dumping their analogue gear as the digital switch-over approaches. a lot of it ends up on ebay, where it generally goes for bugger all & buyer collects. as most of the facilities are based in London, its not hard to cycle down to Soho with a backpack and a shiny one pound coin to pick up, for instance, an NTSC sync generator full of Sandin IP MC1445 video multiplier chips....

more screenshots

these are from december 2009/january 2010. the machine that made these was macgyvered out of my homebuilt modular synth by upping the frequencies of the oscillators, making a few 'glue modules' like sync processors and feeding the output to a broadcast grade RGB to PAL converter i bought on ebay for 99p. i learned a lot, too.. i let the Magic Smoke out of pretty much every module at least once before i worked out why video levels are 1 volt max... electronics explodes when trying to handle 10 volt swings at video frequencies unless you are actually trying to build a transmitter, in which case youll probably have a sufficiently large powersupply, good cooling, a radio license and a much better understanding of high speed analogue electronics than me..
weeee!
BANG!....damn.

1st post. analogue modular video synth stuff.


the above picture is a still from the video synthesizer ive been designing and building over the last year or so. its a fully modular system, mostly inspired by the Sandin Image Processor from the early seventies and the Supernova 12 system built for Australian band Severed Heads. its been prototyped and is currently in the construction phase. i plan on sharing the progress i make on this build (and whatever else i happen to be working on thats fun or interesting) in this blog.

hopefully other people will be inspired to make an analogue video synth too- i reckon that analogue image manipulation techniques never really got the chance they needed back in the seventies to really mature creatively by becoming accessible to a wide spectrum of visual artists (in the way analogue synthesizers did for musicians) before digital processing came in and replaced them completely. boo.

musicians in 2010 have their pick of both analogue and digital tools, and can choose the right one for the right job. video is now pretty much exclusively trapped inside a laptop. damn. i hate laptops...

to this end, ill be sharing various circuits and pcb layouts and construction tips as and when they are tested, working and im happy with them. i like the idea behind the original Sandin IP's 'Distribution Religion' and many of the modules in my system are inspired by Sandin modules, so i reckon its only fair to share the fun. Hopefully other people will get involved and share new circuits too. stay tuned.