[sdiy] string machine technology?

[Ken Stone]

Adding to this, look at my web page for the section on stripping apart organs.

Certainly the organs with the top-octave synths will be from the early '70s
to late '70s, but by then you are starting to see alternates come through too.

Another option would be to buy an old polysynth like the Juno 6. I used to
get a pretty good string ensemble sound out of that.
Some organs already have the work done four toy too - the Lowrey Symphonic
Holiday already contains a string synth. Some of the Yamahas such as the
B-805 already contain one.
For one of the best of the lot though, you'd be hard pressed to go past the
ancient Symphonic Theatre Console by Lowrey, though 1) finding one would be
hard 2) fitting it in your room would be harder 3) extracting the relevant
section from it would be impossible. It used multiple de-tuned oscillators
per pitch, with octaves handled by dividers as per usual. I quite liked its
sound.

Ken

>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.
>>
>>
>++++ Electric Druid ++++
>Web Design & Development
>http://www.electricdruid.net
>
>
>
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
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