[sdiy] Scavanger's lament: what not to tear apart... and other musings...

[anthony]

As you all may well know I scrounge parts out of all manner of old 
electronics gear (some of it is pretty new) for having parts to use in my 
DIY projects but also just for the very real but inexplicable joy I get from 
desoldering a PCB full of parts. A testament to this are the 7 desoldering 
and 6 soldering irons I have gone through since I returned to my electronics 
"hobby" in 2004 while recovering from a very near fatal bout of acute 
pancreatitis (which is now chronic and has claimed all or part or the 
functioning of 4 organs, 5 if you count my gall bladder and I do because it 
came out the same time that my spleen had to come out - my surgeon figures 
another surgery would do me in if my galls stones had flared up on down the 
years; wouldn't be a simple lapro-jobby for me...)

But there have been times when my zeal for collecting and sorting parts has 
led to moments of regret - like maybe I shouldn't have taken it COMPLETELY 
apart: like that boombox with the bad tape deck might have been a great 
docking bay for my Rio Cali Sport mp3 player, that 70's vintage Zenith 
7-tube FM only tabletop radio (but I don't even know if it worked - I never 
even tried it...) and perhaps my greatest lament: the complete disassembly 
of a fully functional (if dirty) Casio Casiotone MT-205 that I got at a 
Goodwill store with the sole intention of cutting the keyboard in half and 
using each half in 2 of my "Synth-a-saurus" projects. I don't really lament 
too much the removal and cutting of the keyboard, but there were some fairly 
decent sounds >>in stereo<<, some good rhythms which you could turn down 
after you programmed you little sequence in. Then there were the external 
drum inputs, which right there were enough to tinker with with other syth 
gates and what-not. And most of the parts just weren't worth not having the 
keyboard whole (a lot of nice 2SC1740SL & 2SA933SL but still...). I did 
manage to reassemble the PSU/mixer/power amp board (which was based on an 
LA4500 which has some fairly decent specs), which I plan to use in my 
semimodular synth. But the tones and rhythms and sequencer are gone forever. 
If it had had MIDI it certainly would have been spared this indignity.

I'm trying to make up for it with a Yamaha PSS-130 which just really isn't 
in the same league, but I think I can tinker with it a bit to make it more 
versatile: like I think the rhythm and the tones come from separate outputs 
from the chip so I reckon I could put to pots on the top and cut in&out one 
or the other. But I did tear it completely apart and put it right back 
together. They were nice enough to mark all of the values on the PCB. I put 
a thicker speaker with a way bigger magnet in and that seemed to make a big 
difference in tone quality. I think I like the idea of using the rhythm 
output to control a modified noise-gate to be gated by an outside signal 
source. I think I'll just whip up a clone of a DOD FX30 with an independent 
sidechain and voila! I might use a better noise gate than that one A Buchla 
230/292C combo would be pretty cool.

And I must say: I really hate the action of cheap keyboards more and more. 
My Novation mm10-X at least has full-sized keys and is velocity sensitive, 
but I like the weight of the action in a grand piano. There's a new Korg in 
a local shop that has an arpeggiator and the keys are almost just like a 
piano. I think it's one of their "Digital Piano" line, I dunno the model #, 
but it has lots of tones; from completely normal to super-spacey and back (a 
bit like my MKS-50 in some ways... but not in many many others...). It's 
only $500 - I wish I could manage that...

But I digress... what I'm saying is that I think I'm going to go another 
route for finding keyboards for my synth projects. I suppose I have room for 
all different types: some velocity sensitive and some not (I don't think 
Hammond organ players lament not having velocity sensitive keys too much for 
instance). What I'd love to do is make something like the Buchla Thunder 
MIDI controller - even better to actually OWN one. But it'd be fun to make 
synth keyboards out of full piano keyboard actions. There's that contraption 
that you can lay over a piano keyboard and use your piano for a MIDI 
controller, but that's not what I'm talking about. I think sequential 
optical encoders along the hammer travel would suffice for velocity 
sensitivity and/or a piezoelectric striking surface.

In my Synth-a-saurus projects (well only one of them so far) I'm going to 
use a pair of piezoelectric gyros on different axes to make up for the lack 
of individual key velocity sensitivity. The wilder you're playing and the 
more you move it about, the more you modify some parameter: like VCA level, 
VCF cut-off, VCF resonance etc.

I have even thought of using these gizmos in a sort of Theremin that you 
play by shaking in various different ways.


cheers,
aa