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Having built the Leslie shown under the topic "Leslie Construction Project," I decided that I needed a Leslie for use at the church. While I was happy with the sound I was getting from the Native Instruments B4 software, I was not completely satisfied with the B4's Leslie emulation (Actually the Chorale emulation is fine--it's the Tremolo speed that didn't quite seem right). So I scouted around for a empty short cabinet--hopefully a 45 or 145--and ended up with a model 25 Orpheus cabinet, with the motor and rotor installed, but no amp or speaker, and began collecting the parts I would need for the project:
Because the Model 25 cabinet doesn't have an upper rotor, I went through the same process as with the 55C--cutting slots in the front and sides of the top, and installing a shelf for the upper rotor. Fortunately I still have the pieces I used to make the routing jig, and was able to use the experiences of the previous project to reduce the time it took me to complete the woodworking phase of the project in less than one day. It took two full days to get it done on the 55C cabinet. Here's a picture of the cabinet, after the slots and shelf were completed:  Because the Leslie Model 25 is shallower front-to-back than the 122-type models, I decided to remove the deflectors from the horn so that there would be a reasonable clearance between the horn and the front and back walls of the cabinet. But now I'm not sure I like the way it sounds without the deflectors--seems like theres more tremolo & less of the complex voicing I'm used to with the other cabinet with deflectors in place. Here's what it looks like:  Here's what the center chamber of the cabinet looks like with the motors and speakers installed:  Notice that I have cut a notch in the left corner of the lower speaker shelf to pass wires thru between the lower chamber and the middle chamber. I did this because the power amp and active crossover will be mounted in the middle chamber--there's not enough room in the lower chamber for them. They'll go on the floor of the middle chamber to the left of the speaker. In the case of the converted Leslie 55C cabinet, I have had trouble with oil seeping down from the lower rotor's slow motor onto the shaft that drives the slow-speed wheel, so I decided this time to use the mounting points already present in the Model 25 cabinet, and mount the lower motor assembly like the upper motor--with the motors below the pulley. That way, any oil would drip away from the drive wheel instead of toward it. It looks like this:  Another interesting problem with the motors I used in this cabinet: Both of these motor stacks came from Leslie units that were designed to go inside a console organ--many organs built by Baldwin and other manufacturers used these units--but these motor stacks were designed to operate in a horizontal position, and they don't work properly in the vertical position needed for traditional Leslie cabinets. The problem is that the slow motor's spindle is supposed to retract from the wheel mounted on the fast motor shaft, but the spring on these slow motors is too weak to keep the motor's rotating part from bottoming out when it retracts. But Rick Prevallet-- Hammond Technician and administrator of the Hammond Age Determination List--was able to sell me some replacement springs that made these motors work right for me. Since these pictures were taken, the amp & crossover have been installed, and the speed-control circuitry has been added (identical to the circuit I used in the 55C cabinet). Here's a front view, taken at the church:  The next picture shows the back side of the cabinet, with the rear panels installed. In this case, the power amp and crossover are installed in the middle chamber of the Leslie, which is the only place there was enough room for them. The speed-switching uses the same circuit and relay type that I used in the 55C conversion, and the speed-switching is done with a traditional-style Leslie half-moon switch that I bought used on Ebay. The switch is mounted on the board shown in the pictures of my rig, right by the Doepfer Pocket Fader unit. In the picture below, the cabinet is connected up to my Native Instruments B4 Clone Rig. You can see a small panel on the back with two 1/4-inch phone connectors--the one on the left is the half-moon switch, and the other is the audio signal from the computer.  And finally, the microphones we're using to get the sound from the Leslie into the house mix. This arrangement was the result of an exchange of messages on the HamTech List. I posted a message asking for advice on hyow to properly set up the microphones, and this was the result -- it works pretty well:  Notice the really beautiful wood grain on this side of the cabinet. When I posted a message in June on the HamTech List asking if anyone had an empty Leslie cabinet to sell, I said I was looking for a beater, since it would probably be painted or covered with carpet. The fellow I bought this one from BEGGED me not to do that to this one--It was really easy for me to agree, because this cabinet is in the best shape of the two I own. |
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All Pictures and Text (c) Copyright 2005 by Stephen Cyr This page last updated March 18, 2005 |
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