Friday, March 20, 2009

Organ Donor

More stuff from the Organ from beside the road! Now we have a rather nice spring reverb -- the actual spring is in turn isolated from the frame by another spring assembly and there is a nice acoustic bag for the whole thing. A bit tempted to investigate a valve (tube if you must) option! There is still booty to be rescued what's more!

Sunday, March 15, 2009

Some new Ideas...

Possible keyboard scanning/arpeggiating for the organ keyboard, with velocity of course...

Saturday, March 14, 2009

...and the Sound Comes out of There...

Back to get more organ waste... Seems in resonable condition despite the water stain -- probably good enough for my ears anyway!

Tuesday, March 10, 2009

Top Octave

The fruits of the Organ salvage... a top octave generator... these are becoming inceasingly hard to find. I have a design that i made that uses a PLD to act as a top octave generator but it is expensive, very power hungry and a pain to program...
Posted by Picasa

Monday, March 9, 2009


Well got a new keyboard from beside the road! Forbin will be pleased... Not the best action but it does have the kimbell allen style springs that are stretched between two contacts. We may be able to do some velocity sensing? The mind starts to wander...

Wednesday, March 4, 2009

More Uncertainty

This is the Gaussian distributed noise. The steps are much finer on this output as it is summed from 15 resistors instead of the 8 from the linear distribution.
Posted by Picasa

Source of Uncertainty 3

This is the stepped output which has a linear distribution. It is running from a 1000Hz clock and giving a nice 0->10V range.
Posted by Picasa

Source of Uncertainty 2

The board being tested. Note the addition of a 10V reference to the CMOS sections at the bottom.
Posted by Picasa

Source of Uncertainty

Have made two of the boards for the Buchla Source of Uncertainty. This board is the SRV or Stored Random Voltages. It is basically a Pseudo Random Sequence that is created from a couple of shift registers. The pseudo random sequence is 15 bits long and cycles every 32767 clocks. If you look carefully you can see the results of some simulation of the circuit on the paper behind the board. The resistor values that Don Buchla choose are a closest approximation from standard resistor values, hence the jaggies. The board is a layout by vtl5c3 and can be found here. I have found a couple of mistakes which I am currently fixing up and will post back to the newsgroup when I have verified the fixes.