Cab for an organ speaker

[agedhorse]

Just an old CTS driver, nothing special. Would work ok for guitar, or bass at very low levels. The original amp was less than 50 watts.

 

[pfschim]

Charitable organizations don’t want old organs or pianos. My friend couldn’t giv away an old Baldwin baby grand.
He cut it up with a sawzall so he could get rid of it.

yeah, I'll give a +1 to this.

We recently sold our home in SW Michigan. My Moms Yamaha C1 baby grand (very high quality CIJ piano that was in perfect shape) was in the house and I could not hardly even give the thing away. I contacted schools, churches, community organizations, piano teachers etc etc .... pretty much no one was interested. At the very last minute I was able to give it away to a student of a local piano teacher, but I was astonished by the whole situation.

 

[Slevage]

Yeah, that caught my eye too! Would love an older Baldwin.

Finding someone with the room for a baby grand is difficult, especially one that isn't plug and play. Then $750 to $1000 to move it (to a repair shop), or to a location where someone is willing to work on it. The rich folks already have one, and the poor folks can't foot the bill.

 

[Fernando Costa]

Woofer is 15" and tweeter is 5?" The Leslie speaker is bizarrely a 6"x9" Because it's a 15" and has a tweeter I immediately went to bass speaker. I have a neighbor with a Peavey Delta Blues, maybe he can do something interesting with it.

I kept the amp/power supply too but, I'd much rather use a guitar amp for it and if I can power it without the power supply, I'd much rather not have the weight of it. How did you make the Leslie spin? Does it want 120 volts AC?

Yes, it needed to be powered by 120v, it was passive so I used a 100W guitar amplifier. I also replaced the small speaker with a 12" one. In this photo you can see the styrofoam drum and the cabinet I made.

 

[brianrost]

Maybe someday I'll do something with the Leslie, first I want to play around with the main speaker for playing bass through. The speaker wasn't in a cab, in the organ. Back of organ was Masonite with a bunch of hole to let out heat. So, it's not like it was in a sealed cab. Can a speaker that was made for an "open back" cab work in a sealed cab? Would I need to add a port? Not to get better low end but, just so it will work?

Many home organs were built like this with masonite back panels. My mom had a first gen Lowrey Genie and gave it to me. I took out the 12” woofer and loaded it into a ported cab built to EV TL806 plans. It worked fine, but I saved up the money to put an EVM12L in there instead and put the Lowrey speaker back in the organ.

 

[Bob422]

Yes, it needed to be powered by 120v, it was passive so I used a 100W guitar amplifier. I also replaced the small speaker with a 12" one. In this photo you can see the styrofoam drum and the cabinet I made.
View attachment 7472677

Awsome.

Yes, it needed to be powered by 120v, it was passive so I used a 100W guitar amplifier. I also replaced the small speaker with a 12" one. In this photo you can see the styrofoam drum and the cabinet I made.
View attachment 7472677

Thank you. I tried it after I read this. Mine was a Hammond Concorde 2107. My Leslie has 2 speeds, slow and fast. It also has two motors. Small motor for slow, larger motor for fast. The thin red and black wires are for the speaker. First I put power to the grey wire,( on other side of connector it goes to both power cords, one for each motor) and the blue wire. It didn't do anything. Disconnected the blue wire and connected to the yellow wire and got it to spin slow. I'm wondering if I need to put power to both motors for fast speed and if you still have yours and it's the same and, or, remember how you hooked it up.

 

[Fernando Costa]

Awsome.

Thank you. I tried it after I read this. Mine was a Hammond Concorde 2107. My Leslie has 2 speeds, slow and fast. It also has two motors. Small motor for slow, larger motor for fast. The thin red and black wires are for the speaker. First I put power to the grey wire,( on other side of connector it goes to both power cords, one for each motor) and the blue wire. It didn't do anything. Disconnected the blue wire and connected to the yellow wire and got it to spin slow. I'm wondering if I need to put power to both motors for fast speed and if you still have yours and it's the same and, or, remember how you hooked it up.

View attachment 7472766

Hey, I removed this connector. Each motor has two wires, you must connect one of the wires from each motor to one of the 120 volt AC wires. The other 120 volt wire and the two other motor wires must be connected to a switch to change speeds. The speaker wires are connected to an amplifier.

 

[Bob422]

Hey, I removed this connector. Each motor has two wires, you must connect one of the wires from each motor to one of the 120 volt AC wires. The other 120 volt wire and the two other motor wires must be connected to a switch to change speeds. The speaker wires are connected to an amplifier.

View attachment 7473315

Thank you. There must be something wrong with the fast/big motor. My only hope was that it might work if both were being powered at the same time.

 

[Bob422]

I thought of another hope, I'm an old man with memory issues and I couldn't remember if when I tried the fast motor, was I looking at the big pulley that's easy to if it's spinning or, not or, did I look at the small pulley on the motor. Maybe it was spinning but, not making the belt move and the other pulley. The belt adjustment is out as far as it can go, maybe it needs an new belt but, it worked in the organ. I got rid of the connector, was going to eventually so, why not eliminate it now. Plugged it in, still nothing other than a quite hum. There's some maintenance info on a label inside the enclosure. Won't work if belt is too tight. But it worked in the organ. I loosened the wing nut and it moved slightly without me moving it. Plugged it in. I now have two speeds. Only thing I can think of is, I have enclosure in two block of wood, (speaker connector is on the bottom) instead of hanging from a shelf in the organ. Again, Thank you Thank you Thank you.

 

[Fernando Costa]

I thought of another hope, I'm an old man with memory issues and I couldn't remember if when I tried the fast motor, was I looking at the big pulley that's easy to if it's spinning or, not or, did I look at the small pulley on the motor. Maybe it was spinning but, not making the belt move and the other pulley. The belt adjustment is out as far as it can go, maybe it needs an new belt but, it worked in the organ. I got rid of the connector, was going to eventually so, why not eliminate it now. Plugged it in, still nothing other than a quite hum. There's some maintenance info on a label inside the enclosure. Won't work if belt is too tight. But it worked in the organ. I loosened the wing nut and it moved slightly without me moving it. Plugged it in. I now have two speeds. Only thing I can think of is, I have enclosure in two block of wood, (speaker connector is on the bottom) instead of hanging from a shelf in the organ. Again, Thank you Thank you Thank you.

Okay, two important points: the motor coupling is done between the shaft of the small (slow) motor and the pulley of the large motor, which has an o-ring that must be in good condition (I recommend a new one). This is adjusted by changing the angle of the small motor shaft; it's easy. There can't be any lubricant in this coupling, obviously.
If these parts you are using are missing the original Leslie driver, the switching may cause noise in the audio; if this is the case, use solid-state relays.

The SSR functions simply as an "electronic switch".

Unlike a mechanical switch, which generates a spark (electric arc) when opening/closing — causing that "pop" in the speakers — the "Zero-Cross SSR" only turns on or off when the mains wave passes through the 0V point. This almost completely eliminates electromagnetic interference (EMI).

Simplified Wiring Diagram

Here's how you should set it up to switch between Motor A and Motor B:

1. Common (Neutral): Connect the "Neutral" wire from your 120V mains directly to one of the wires of each motor.
2. Live (Hot): Connect the "Live" wire from the mains to the L1 output terminals (or pin 1) of both SSRs.
3. Output to the Motors: Connect the output pin of SSR 1 to the remaining wire of Motor 1.
Connect the output pin of SSR 2 to the remaining wire of Motor 2.
4. Control Circuit (9V DC):
The negative (-) terminal of the 9V battery/source goes to pin 4 (-) of both SSRs.
The positive (+) terminal goes through a selector switch (SPDT type) that directs the 9V to pin 3 (+) of SSR 1 "OR" to pin 3 (+) of SSR 2.

Recommended Components

SSR: AC-DC type (Ex: Fotek SSR-25DA) 3 ~ 32 VDC. Ensure it is Zero-Cross.
Selector Switch: A simple 3-pin switch (On-Off-On) to toggle the 9V (or any 3 ~ 32 VDC) signal.
Protection: A 5A fuse at the 120V phase input is always recommended.

*The original Leslie controller has a brake circuit to brake the rotors faster. This feature is lost with this connection; in any case, I didn't notice any difference. I used the same setup with my larger Leslie speakers that I converted to passive and used with better external amplifiers, allowing me to use modern audio processors.

 

[Fernando Costa]

One detail: the small (slow) motor transfers the slow speed "through" the large motor, hence the importance and precision that the coupling must have. They work together, and when using fast speed the coupling breaks down as it is made by the induction that moves the small motor shaft.

 

[Bob422]

I'm done. I want to thank everyone for their help, especially @Fernando Costa . The 15" woofer was a bust, it's gone. Guitar, bass, nothing sounded good through it. I had high hopes for bass. My thought was a speaker for an organ would have to be built more robust because, holding a key down = continuous use.

Still can't believe how good guitar sounds through a 6x9 speaker.

 

[JimChjones]

The wood in the cases and structural parts of old pianos and organs is typically as good as any that could be purchased at the time and it's a great source for woodworkers.

The last speaker cab I built, which features a decorative hardwood finish, has a fair chunk of scrapped piano in it.