[sdiy] string machine technology?

[Tom Wiltshire]

If you really wanted to build one, you could try asking these people 
for a top octave generator:

http://www.organservice.com/crm/topdividers.htm

The rest of it should be simple - a pile of binary dividers, followed 
by perhaps some filters and BBD chorus/delays.

Banzai Effects have a good collection of BBD chips:

http://www.banzaieffects.com/Delay-Chips-Clock-ICs-c-373.html

Other people who've said that the cheapest/easiest way is to buy an old 
organ are right though. I once tried to buy one on eBay, and put a 
couple of bids in, and finished up with two organs for £30! If you've 
got transport, they'll be even less - most people want you to take them 
away.

Make sure you get a nice 1970's one, not one of the 1980's ones that 
are based on the M108 polyphonic organ chip or similar. Of the two I 
bought, I had one of each. The 70's one is a yamaha, and uses separate 
oscillators for the top octave (early 70's), followed by the dividers 
and then a couple of boards of filters. This would be ideal - just add 
a board full of BBDs - perhaps the effects board from a dead polysix. 
It even has quite a nice sounding amp and yamaha's weird vertical 
rotary speaker. The other is a cheap 1980's Italian thing based on the 
M108, which sounds awful, and doesn't have half the options for 
modification.

Good luck,

Tom


On 2 Nov 2006, at 07:21, Peter Blackett wrote:

> Dear Rykhaard, and DIy list.
> as mentioned before if you are copying most of the production string 
> machines they use top octave generators and BBD delay ic chips to 
> produce the chorus effect.
> it would be possible to use separate oscilators,to rep[ace the tog ic 
> , but I don't think it is easy to reproduce the chorus effect without 
> the BBD delay ic's.
> [ if it is please let me know ! ]
> But I would be interested to know what the Original String machines 
> built by Ken Freeman [ is that the correct person ? ] used.
> of course if you have the space you could probably find a late 1970's 
> organ that has a string synth built in at a good price.
> regards Peter
>
> D.A.M.I.A.N. wrote:
>
>> I thought of this tonight at work - finding a service manual for a
>> String Machine, and cloning it.  Then my brain wandered off into the
>> areas of simple design.
>
>
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