Has anyone come up with a way to adapt a standard "halfmoon" type "Choral/Tremolo" switch for use with the Leslie 3300 to control rotor speed? The 3300 requires the use of a momentary normally open (N/O)switch, and the unit triggers on a switch transition from closed to open. If you close the switch, the speed doesn't change until you release the switch, and if you hold the switch closed for a second or so, the rotors will stop. This makes it impossible to use a standard Leslie speed switch which is a 2 position maintained on/off switch. It sure would be nice to have the traditional functionality rather than constantly toggling a foot switch and never being quite sure which state things are in.

Surely someone has come up with some kind of "something-stable one shot thing-a-ma-jig" for this purpose?? I betcha it wouldn't take much to design a simple one chip device for this purpose. The output of said device would have to pull the trigger input of the Leslie 3300 low for about 250 ms then go back high again every time it's input is transitioned and then maintained by the “Choral/Tremolo” switch from Choral to Tremolo (switch closes) or from Tremolo to Choral (switch opens). It would be really nice if this device could be powered from the Leslie 3300 input . . . if not, then a 9V alkaline battery.

Are there any EE's or other cognoscenti out there who are eager to part with their knowledge and help to design such a device??

ps: Yes, this would kill the rotor "brake" function

You should be able to use a standard DPDT (Double-Pole, Double-Throw) switch... you could wire it as On-Off-On with Off in the center position, so it'd be like a half-moon switch with a click in the middle. It would also let you stop the rotors by putting the switch in the middle position.

Yes? No? Seems pretty straightforward to me, at least on paper...

Don't think it's that simple. The Leslie wants a normally open momentary contact switch to toggle between fast and slow. Press and hold for a full second for stop.

What is your organ?

Hammond sells a halfmoon switch that you plug into the foot switch jack on the back of their suzuki clones. I have never used it. I use the kick switch on the expression pedal.

http://hammondorganco.com/optional_acc1.htm#9770

I'm running VB3 and using an Axiom 61 as a keyboard. Alas, no Hammond - yet.

I have always had great luck asking Ray Gerlich any questions I had regarding Hammond / Leslie equipment. If there is a way to jerryrig any of those half-moon switch options he would probably know the mod if one was needed.

A quick and easy way to control the speeds would just be to wire up a doorbell switch to a long instrument cable with a 1/4" jack on the other end. Velcro the switch body to the keyboard. You wouldn't be able to tell the current speed without looking at the 3300 though. I found a toggle switch that springs back to the center and mounted it in a small project box. It has 2 sets of contacts, 1 open and the other closed. Whichever way I move the toggle, they close/open. I can use one switch to control 2 Leslies.

Good Luck.

Correct. The switch has 3 positions: for the sake of argument, we'll call them left-middle-right. At the left position, it's open. Switch to right, through middle position, and the switch changes to closed and open again; the Leslie changes speed. Same thing going in the other direction. This isn't exactly like a traditional half-moon switch, but it'll do what the poster wants, in that it'll change the state of the Leslie.

If he wants it to stop, leave it in the middle (closed) for the 1 second, and then move it to either left or right and it'll remain stopped (at least based on the description, that would work).

What's wrong with that?

Use the 11pin connector and wire the switch to that. It wants a non-momentary switch, afaik.

Listening is a second common way.

Larry.

Usually that works pretty well. I thought his concern was that it be spinning at the desired speed when he starts playing. To me the best way to control a 3300 is with an XK-3/c. You get speed indicator LED's right near the buttons, can control the speed via the buttons, expression pedal kick switch, stand alone foot switch and/or half moon switch and as a side benefit you get great tone and playing interface to boot.

Hey, don't pay any attention to me, I was just making a snotty comment. Unless I can feel the wind on the back of my neck (which was actually quite cooling back in the stacks-o-leslies era of the late 60s), I can't hear how fast a leslie is spinning either until I play something!

Larry.

But one of the greatest sounds in the world is the sound of sustaining a chord while the leslie is building up speed.

That's why I think he wanted to be able to make sure it was going slow when he started.

Wow - such a profusion of thought and comments . . . cool Wanting to know exactly what speed is currently selected isn't as important as being able to modulate quickly and reliably between slow and fast. What this does is provide a subtle but expressive warble in a passage or held note. Ya switch to fast just long enough for the motors to start to accelerate, then switch back to slow until the speed settles down again, then repeat. The warble effect is nice and requires absolute certainty of manipulation of the switch and response of the rotors- otherwise it get's away from you and ruins the effect or the rotors stop which also ruins the effect. To me, it is much harder to obtain this effect with a momentary switch. The timing between transitioning between slow and fast is critical and is much easier to control with the two position switch. Also, it's what I'm used to after many years of playing and I just can't seem to adapt to the "new" scheme - or rather I just don't want to.

I'm gonna call Ray Gerlich at Hammond.

This won't help your current situation, but with the 2101/MkII you can connect a MIDI cable and send mod wheel data to act like a gas pedal to control the speed. You might even be able to connect a volume pedal to your controller to generate the mod wheel data.

If all you want to do is quickly change speed, any N/O momentary switch connected to the 3300 will work. That is all the kick switch is on the XK-3/c's expression pedal. A doorbell switch will work just fine. All you have to do is press it for no longer than it takes to close the circuit to alternate speeds. Holding it for a second will stop the rotation. I'm sure a local electronic parts store or Mouser.com etc. will have a self centering toggle switch.

Hey everyone - thank you very much for your input. Special thanks to B3-er who suggested using the pins on the 11 pin connector. He was absolutely correct and I'm successfully using a traditional halfmoon "Chorale\Tremolo" switch now.

The actual switch inside the halfmoon housing has 2 separate sets of contacts. 1 set closes when the switch is in the “Chorale” position, the other set closes when the switch is moved to the “Tremolo”position. It takes a small piece of jumper wire, a 3 conductor cable instead of a 2 conductor cable from the switch, and a soldering pencil to create a SPDT switch out of the two sets of contacts. In this illustration, Pole A goes to pin 8 and Pole B goes to pin 7, and the “throw” or common goes to pin 4 on the 11 pin connector. The top switch illustration is shown in the "Tremolo" position, the bottom switch is for illustration purposes only but is shown in the "Chorale" position. If you hold the switch between the 2 positions so that both pins 7 & 8 are both “floating”, the rotors stop.