Hammond tonewheel organ (midi?)

[unfiltered37]

Anyone heard of an original hammond tonewheel converted to trigger using midi or CV even?
Can anyone explain how the amp works, i.e. are all of the pickups summed and all of the different colored wires correspond to each pickup? In other words does each tonewheel have its own audio path.

I had a brainstorm about getting a tonewheel organ to output each pickup or wheel to a VCA and using it for a remote drone box controlled by midi. If I could convert the keyboard to midi or have each pickup on one wire (at I assume mic or instrument level) or both, I could chop my M3 down to just the pickup tonewheel housing.

[Kevin Lightner]

Just something to ponder:
Many Hammonds have multiple switches under each key.
Some for each drawbar, afaik.
There may also be additional contacts for percussion.

So it may not be quite so simple to do the circuitry to key a Hammond.
Regardless, it's a good idea and I wish you success.

[Just Me]

There is a contact under each key for each drawbar. There fore, a buss bar for each drawbar. How the audio path works from the tone wheel to the big transformer and then through the vibrato scanner to the preamps is a mystery to me. It would appear you would need 10 VCA's per key.

[EMwhite]

And just to add; I've got an M3 and Percussion was an option, at least on mine it only works monophonicly like a legato Env gen (if a key is depressed it will not 'fire').

Based on seeing others play B3s it works differently but I could be wrong; never had the pleasure. If you already have the M3 rock it out; if you were just thinking of picking one up, do it; they are practically given away these days but very B3 like; you would be surprised at the number of commercial hits recorded on an M3 (Green Onions, Boston's first album).

[MC]

Very expensive proposition and VCAs wouldn't be the best solution because they won't replicate the "key click" transient that is a crucial part of the B-3 sound.

[atkbg]

Not to mention the variations between individual organs.

Can't find the link, but someone was doing this. They pulled generators from M or L series and key'ed them via midi.

However, as Kevin stated, there are multiple buss bars under each key going to each drawbar and one for percussion keying. This creates variable pressure keying since pressing the key slightly only actuates the upper buss bar/draw bar. While you could map velocity to these, I think you really be looking at a labor of love.

Also, the percussion circuit is "monophonic". (Actaully, the keying circuit from the ARP OMNI is similar. I think they called it "One Shot".) Basically, all keys must be released for the next key to trigger the percussion.

[EMwhite]

(monophonic percussion) Interesting. I'll have to watch that Rachel Flowers videos again. I though that maybe the B3 was this way or that Keith had a tricked out model. I know that I cracked the tube associated with the circuit at one point and percussion stopped working (since repaired); not sure how difficult it would be to mod it or how practical it would be. (I'm a mere amateur organist, just ask my neighbors. Each spring I awaken the neighborhood animals with a stirring rendition of "Take me out to the ball game". My Leslie has a 20 foot cable and I put it in the center of my driveway)

[atkbg]

Not actually monophonic. More of a single trigger.
You can hit a chord and all notes in the chord will trigger the percussion for each note. The percussion will not retrigger until all notes have been released (on the upper manual). If you play staccato, each note will trigger the circuit. If you play legato, only the first note will trigger the circuit.

[synthaxe]

(I'm a mere amateur organist, just ask my neighbors. Each spring I awaken the neighborhood animals with a stirring rendition of "Take me out to the ball game". My Leslie has a 20 foot cable and I put it in the center of my driveway)

I just about fell off my chair at work with laughter!

[Kevin Lightner]

Fwiw, I had the same idea a long time ago.
I took my L-102 tone wheels out and planned to make a computer controller using an Apple II+.
MIDI hadn't yet been invented.

But as I got deeper into things, I realized I'd have to make some huge matrix of switching circuits.
I started to draw things out on paper and I think I had chosen 4066 cmos switches, but it all got out of hand.
It would have taken 2 4066s and a transistor for every note, plus a computer interface.

I'd never touched a B3 then and didn't know if all Hammonds had all those contacts, but mine did.
Thus my "as far as I know" response above.
Thanks to all for confirming my 30 year old memories.

I recall also abandoning the idea because it became obvious, that unlike like most Hammond emulators today, the keyboard was actually sort of velocity sensitive.
The drawbar tones were keyed sequentially as the key was pressed.

So, it's a lot of work.
As said in Godfather 2: "Difficult, but not impossible."

[Rob Smith]

Keith Emerson used a C3 on the Black Moon tour that had Midi. Will Alexander his tech at the time wasn't crazy about it. I do not know who did the conversion, But Emerson does use Goff Professional in Connecticut for all his Hammond work. http://www.popeye-x.com/tech/willalexander.htm

[Kevin Lightner]

MIDI out wouldn't be too difficult.
MIDI in is another story altogether.

[MC]

The Hammond BA had an Aeolian player piano mated to a Hammond organ, either model A or B. Never seen the schematic for one of these. I do know that the keys did not depress when the player was running.

[MC]

Update: check out the link with pics. The BA use pneumatic actuators that pulled down the contact arm under the key. Gotta love old school!

http://www.organhouse.com/aeolian_hammond_player.htm

[Kevin Lightner]

Amazing!

I wonder if when a roll plays too many notes at a time, it drops pressure and notes?