[sdiy] Tonewheel questions

Sat May 29 02:23:18 CEST 2004

Reply Posted May 28, 2004

AKA encoder.  I have a couple of servo motors here with sin/cos 
encoders....I never thought of using them to generate tones....even more 
fun, I can servo them, and in a way lock them together so that they would 
rotate at precise rations....hmmm.....interesting project....

(Wheels are turning in my Mind.... :-)

At 06:43 PM 5/28/2004 +1000, Ken Stone wrote:
>The point of a synchronous motor in Hammonds was to keep the pitch from
>wavering. Hammonds are shocking when run from small petrol generators!
>
>For a simple way to experiment, take a look at old video players. In a lot
>of them you will find some kind of feedback mechanism on the capstan motor
>or video drum motor. These sometimes take the physical structure of a tone
>wheel.
>
>Ken
>
> >I'm thinking of building a vastly simplified tonewheel organ.  What I'm
> >looking at doing is a fan motor running off of wall-current with a dimmer
>(the kind
> >used on house lights) to vary the speed of the motor (overall pitch), this
> >motor being connected to a shaft with 5 (or howeverman) wheels.  My 
> questions
> >are as follows:
> >1) Will the fan assembly work?  I know some fans don't 'like' lower 
> currents
> >than they're used to seeing, what sort are these?
> >2) Anything I should know about these dimmers beforehand?
> >3) How many wheels is it reasonable to have on the shaft?  (As I said, I'm
> >thinking five, but could be swayed in either direction).
> >4) It's mainly for drones, so a dimmer as pitch control isn't a problem and
> >no EG's shouldn't be a problem, but what about output level?  What 
> should the
> >line-out level be?  And howsabout a 'to modular out' level?
> >5) What's the cheapest sort of inductors to use?  I don't like the sound of
> >guitar pickups, they end up as a little more expensive than I'd like to
>use.  I
> >would like to have separate ones for each wheel so I can use pots as
> >'drawbars'.
> >6) Unrelated, but I have a keyboard labeled GC-7A.  It has no maker 
> label on
> >it, and basically outputs a square wave with pitch determined by key being
> >pressed.  Ugly sound.  It has two 'timbre' controls that change the sound -
>one
> >seems to add tremolo, the other something I can't quite identify.  It 
> has an
> >output labeled 'karaoke' but no line out, which shares some solder with 
> the 9v
> >in (I run it from batteries).  I'm thinking I may circuitbend it, but I can
> >find no info whatsoever on it.  Anyone have any clue?  Oh, and it plays 
> a wide
> >selection of obnoxious Christmas melodies.
> >(I got it for 2.50 USD from the thrift store.  Maybe if I didn't blow 
> all my
> >money on crap like that I could afford the 100 dollar organ they have,
> >unlabeled maker but it has enough stops that it looks like fun).
> >Any help much appreciated.
> >       -eric
> ><HTML><FONT FACE=arial,helvetica><HTML><FONT  SIZE=2 PTSIZE=10
>FAMILY="SANSSERIF" FACE="Arial" LANG="0">I'm thinking of building a vastly
>simplified tonewheel organ.  What I'm looking at doing is a fan motor
>running off of wall-current with a dimmer (the kind used on house lights) to
>vary the speed of the motor (overall pitch), this motor being connected to a
>shaft with 5 (or howeverman) wheels.  My questions are as follows:<BR>
> >1) Will the fan assembly work?  I know some fans don't 'like' lower
>currents than they're used to seeing, what sort are these?<BR>
> >2) Anything I should know about these dimmers beforehand?<BR>
> >3) How many wheels is it reasonable to have on the shaft?  (As I said,
>I'm thinking five, but could be swayed in either direction).<BR>
> >4) It's mainly for drones, so a dimmer as pitch control isn't a problem and
>no EG's shouldn't be a problem, but what about output level?  What
>should the line-out level be?  And howsabout a 'to modular out' 
>level?<BR>
> >5) What's the cheapest sort of inductors to use?  I don't like the
>sound of guitar pickups, they end up as a little more expensive than I'd
>like to use.  I would like to have separate ones for each wheel so I
>can use pots as 'drawbars'.<BR>
> >6) Unrelated, but I have a keyboard labeled GC-7A.  It has no maker
>label on it, and basically outputs a square wave with pitch determined by
>key being pressed.  Ugly sound.  It has two 'timbre' controls that
>change the sound - one seems to add tremolo, the other something I can't
>quite identify.  It has an output labeled 'karaoke' but no line out,
>which shares some solder with the 9v in (I run it from batteries).  I'm
>thinking I may circuitbend it, but I can find no info whatsoever on
>it.  Anyone have any clue?  Oh, and it plays a wide selection of
>obnoxious Christmas melodies.<BR>
> >(I got it for 2.50 USD from the thrift store.  Maybe if I didn't blow
>all my money on crap like that I could afford the 100 dollar organ they
>have, unlabeled maker but it has enough stops that it looks like fun).<BR>
> >Any help much appreciated.<BR>
> >       -eric</FONT></HTML>
> >
>_______________________________________________________________________
>Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
>Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
>Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

         -Jim
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