organ leslie for guitar

[spsimmons]

So, I've worked on my schematic enough to feel like it might work. Everything to the right of the connector is already existing except for the two lamps by the motors and the (possible) extra speaker. I tried to draw it as accurately as possible.

I still don't know what transformer to use. Step down to 9Vac, maybe?

Is the diode at relay 2 necessary and/or oriented properly?

MARK- I could ignore the relays, but where's the fun in that? It would be a simple wiring job and I'd rather try to use this as a learning opportunity. Plus, I still think it's safer to run 9 or 12 volts to a footswitch than 110.

Is my design bunk? Where are the problems? What am I not getting?

Here's a footswitch that I think might control it. (Just an example.)

Fender FM65DSP and Super-Champ XD Footswitch and more Guitar Amplifiers at GuitarCenter.com.

[chipprogr]

I didnt see the tread of posted messages here. This is dead simple- forget the relays and step down stuff. Your going to concentrate on just getting AC to the motors.

Simplest way is to scrap the controller and do some of this manually. The triacs and relays on the controller board are just there to allow low voltage to turn on higher voltage to the motors. They are redundant as it could have all just been done with relays alone.

There is a 6 pin plug connected to the motor (4 wires) and (2 wires) connecting to the speaker. Pins 3 and 6 will go to your guitar amp's speaker output. Check the ohms of the speaker so you dont overload your guitar amp. Goto your local radioshack or electronic supply place and get a Single Pole Double Throw SPDT switch that has 3 positions, on-off-on. Pins 4 and 5 of this plug will connect to your AC cord neutral (white wire on ac cord) and the center contact of the switch will connect to the AC hot pin (black wire). Now there are 2 outer terminals on the switch left. Doesnt matter which you use, as you will figure out which is fast and slow when testing happens. Hook one of the outer switch terminals to the motor pin 1 and the other to motor pin 2.

This configuration gives you (slow - off - fast ) when you flick the switch.

I assume no responsibility for any harm that you may cause , or is caused to you by doing this, these are mearly sugesstions and you will want to refer to a local expert if you are unsure of what your doing.

Good Luck- Eric

[chipprogr]

I have seen an Allen organ tone cab that had three 12"s and three tweeters all mounted on a spinning baffle. Quite the system. Good for a big church. It was about 3'X3'X5' high.
Scott

I have repaired many allen organs in my time and seen these. Poor attempt at a leslie. Leslies work on doppler shift of the sound, these monsters were just speakers on a rotating baffle.

[Danelectron]

I agree with Chipprogr. I tore a leslie out of an old wurlitzer and did this very thing, but I cut off the pin connector altogether, wallowed out the baffle for a 10" celestion, and mounted the works in a cabinet.
I used the high / low speed switch out of the organ, but am going to ditch that and get a speed control for the high speed motor alone. The high / low set up avoids a very large span of expression that can be had.

Friggin awesome for Robin Trower type blues and it astounds people who have never seen organic effects. (No pun intended)

[Mark Hammer]

It actually doesn't matter very much if it is the speaker that moves or the baffle. What matters more is:

a) whether the baffle is sufficiently restrictive or directional in what it does to the speaker's output as to mimic a horn pointing in a different direction,

b) the radius of the baffle's "throw".

The sound source needs to move in a fashion that puts it "over here" and then "over there" and "over there". The same motor rotation speed with a longer radius makes for greater spatial displacement per unit of time.

The nice thing about the vertically-mounted "cheesewheel" baffles is that the have a fairly long radius for the amount of space they occupy, and the moulded stryofoam baffle directs the sound fairly efficiently.

A buddy of mine in town makes the Retro-Sonic line of pedals. He did a nice job with the resurrection of the old Boss CE-1 Chorus Ensemble (which has been well-received), and thought he "knew chorus pedals" until he came over to my place and I got him to play through a true rotating speaker for the first time. Very different experience that opened up his eyes.

As has come up on forums repeatedly, electronic simulations of rotating speakers can leave the user unimpressed or unable to hear any vallue added beyond what a phaser, Uni-Vibe, or chorus pedal does....until they hear it in stereo. It's that spatial element that goes the extra mile and "convinces" the user.

[olive2sing]

Is the diode at relay 2 necessary and/or oriented properly?

Not necessary if your using ac relays

[chipprogr]

if you put AC to the relays as shown, you will surely burn out the transformer. they are dc relays until you cut out the diodes.

[spsimmons]

So, if I added a diode like the one on relay 2 to relay 1, could I then run them both off dc? This might be easier. I have several wall warts laying around. I'd just need to wire in an ac outlet.

Are the yellow components at relay 1 capacitors? They are not labeled the way I expect capacitors to be labeled, but they don't look like resistors or diodes either. This was built in 1975, maybe the labels have changed?

[Rhodesplyr]

The classic Leslies (122, 147, etc....) use a SPDT relay to do the switching. The two motors are referred to as the "motor stack." Basically, the relay turns one motor off and the other on. When the slow motor turns on, the magnetic force of the windings pulls it into contact with a rubber tire on a wheel attached to the fast motor.

Leslies in the 122 family use a DC relay to do the switching; 147s use a 120V AC relay. I used a footswitch running 120V for years on a 145 setup I used to have. That's what's in the standard chrome wedge Leslie Combo Preamp for 147 family speakers.

You do have to pay attention of the original orientation of the slow motor because it depends on gravity to do some of the work. If you take one that was installed sideways and mount it vertically or try to flip it upside down, you'll have to adjust the springs around the shaft to compensate because the slow motor may then either not engage or refuse to disengage.

When properly tensioned, the belt should slip a little going from slow to fast. It's supposed to act like a clutch.

It can be worth your while to disassemble the motors, clean the bearings, and re-oil them. Do not use WD-40. It's not made for porous bronze bearings, which are what the motors use. But be warned that it can be a tricky and time-consuming task.

[chipprogr]

motor control = cheap light dimmer from hardware store. Think about what an overhead fan speed control is in your house.

[Rhodesplyr]

motor control = cheap light dimmer from hardware store. Think about what an overhead fan speed control is in your house.

And, based on years of combined experience on the Hamtech list, you will burn up the kind of motors used in Leslies if you try this. There's a reason that professionals have had to engineer sophisticated electronic controls to try to get slow speeds from the earlier (pre-1963) Leslies that had only Fast motors.

[chipprogr]

Rhodesplyr; im seriously interested about your comment. Ive seen people do this with sucess and have not seen any burned up. Can you please elaborate- i do want to educate myself here. If i am in error, i want to know.

Ahh- i did a little research, now i know why. Its the type of motor used. Never really paid attention to that when working on hammonds. Typically i work on the amps in the leslies, never paid much attention(or had to) to the leslies' motors other than lubrication of the bearings.

That also being said, 1 poster has whats looks like 2 back to back shaded pole ac motors, the fan speed control is meant for that type motors. The other type like the pre-63' , it will damage.

[Rhodesplyr]

I guess it depends on which case we're talking about. The photo posted by spsimmons shows the classic Leslie motor stack adapted for use with an internal organ speaker. For those, as has been stated, the switching is fairly simple. They are both 120VAC motors, and you just have to switch one off at the same time you switch the other on. You can do it directly with a SPDT switch or via a relay, though either method requires robust contacts. The back EMF from the motors can cause arcing and burning of the contacts. It helps to have some caps across the switches to supress this.

I'm less familiar with the motors of the type posted by marcrochotte.

The dual motor stacks used in post-1963 Leslies use the exact same type of motors as in the earlier single-speed Leslies, with the addition of the Slow motors. The difference is that the shaft goes all the way through the Fast motor rather than having an end bearing. (This can lead to some maintenance issues because the Fast motor rotor in the two-speed setup has to be shimmed to the correct position by special washers. These can wear and throw things out of alignment, and, when you go to replace them, you find that they have odd dimensions and are not off the shelf parts!)

The big change in Leslie motor controls was introduced by Hammond/Suzuki; they use a single variable speed motor rather than the two-motor system. Though it's simpler mechanically, there are reports of problems with the new system. It seems that properly implementing variable speed motor controls is challenging.

These days, I'm finding it more and more common that the two-speed Leslie motor stacks need complete disassembly, cleaning, and rebuilding to work their best, and it's no small task. There are lots of little tricks to getting the best results.

Also, if you ever have trouble with a two-speed Leslie inducing hum in a nearby system, it's the Slow motors. They radiate a strong EM field, much more so than the Fast motors. You never put a Leslie on the left side of a Hammond organ from the player's POV because it will induce a very loud hum via the organ's matching transformer.

Rhodesplyr; im seriously interested about your comment. Ive seen people do this with sucess and have not seen any burned up. Can you please elaborate- i do want to educate myself here. If i am in error, i want to know.

Ahh- i did a little research, now i know why. Its the type of motor used. Never really paid attention to that when working on hammonds. Typically i work on the amps in the leslies, never paid much attention(or had to) to the leslies' motors other than lubrication of the bearings.

That also being said, 1 poster has whats looks like 2 back to back shaded pole ac motors, the fan speed control is meant for that type motors. The other type like the pre-63' , it will damage.

[spsimmons]

Rhodesplyr- Can you elaborate on the use of caps to suppress the back EMF from the motors. Specifically where they would be placed and what type would be used.

I've mocked up and tested my design and it seems to work fine. I used a 9v 100mA wall wart for the transformer and a dc relay at the relay two position without the diode I have drawn there. If there are things I can do to make the design more robust and trouble free, I'd rather do it in the design phase before I start soldering things up.

I found that 9v actuates relay one, but since it has no specs printed on it, I'm left just hoping that I'm not going to damage it by applying either too much or too little voltage. All I know to do is try it and if it burns up, replace it with a relay just like I'm using for #2.

[Rhodesplyr]

I'm in a bit of a rush tonight, so my suggestion for you is to look up the schematics for the Leslie 122 and Leslie 147 amplifiers which you can find instantly via Google. The relay circuits are part of the amps. The capacitor value is 0.1uF @ 600V. I can't recall offhand what the amp rating of the contacts is, but I'll try to look it up for you. Don't be confused by the "jumper plug" on the schematics. It was used for a brake that hardly anyone ever used.

Leslie used fairly standard Potter & Brumfield relays for switching, though these days, it's easier to find the 147 type that used 120VAC as an off the shelf part. The 122 used a more complicated DC switching system.

Most Leslie vintage parts places will carry some version of these--at quite a range of prices.