Leslie atop a Lowery project

[nonsuchpro]

Hey all,
The recent super snow storm Jonas made me a very productive person, hehe.
I finally did my "Leslie atop a Lowery" project which is basically putting a rotating horn on the top of my Lowery C300 Promenade Organ. It came out better than expected. The Lowery has a 1 speed internal rotating drum that is that is about to become a 2 speed w/brake. I've had all these parts on-hand for a while now, I'm glad they are getting used. Check out the pics and vid! And if anyone is interested in doing something similar, don't hesitate to ask me for help.
Rob

Video
https://youtu.be/Pwh9-6yAAk0

Pics

[Dread2]

Rob that sounds Awesome!

I have the same organ and I would love to do that mod. How did you wire it?
Is it going through the leslie amp with the ten inch and twelve inch still in the circuit?

[andyg]

From the sound, clearly not, as there's no ramp up/down of the lower rotor. The lower flute frequencies are very clearly 'straight' with no trem at all.

There's the next project for nonsuchpro. Get it running with the internal drum as well. Second project could be learning how to spell Lowrey! ;-)

Should be easy enough - take the signal that's going to the internal leslie's speaker and put in a passive crossover at 800Hz. Highs to the horn, mids to the leslie drum. IIRC, the low end had an electronic tremolo, or was that just in the spinets that had an 8" speaker for the leslie drum. And you could also try what the UK Sharma (leslie clone) company did. Make the horn half size and put it inside the organ. The 'Sharmony' was the only commercially made organ to have both drum and horn internal rotors, as far as I know.

[Dread2]

At about 1:23 in the video Rob hits a foot switch to turn on the internal drum and show it to the camera so he was demoing the horn without the drum spinning. He also talks about putting a two speed motor on the drum.

Would he have used a separate amp for the horn? It seems like a passive crossover is the easiest route.

And yes, you are right about the electronic tremolo:
"Placing the Leslie Tremolo Switch to on allows the Flute Lamp Driver DC voltage to be modulated by the vibrato" thus "...creating a tremolo effect for the the Low Frequency Main Channel Flutes."