Leslie 51C restoration: For the love of an albatross

At the risk of sounding like the dreaded involuntarily celibate teenage Nice Guy that blames his dearth of female prospects on the archetypal douchebag “Chad,” we always fall for the ones that hurt us.

I found a banged up, sweaty, untested Leslie model 51C on a local eBay listing. The Buy It Now price was good, but not a steal. After all, a 51C even in top nick is neither a 122- nor 147-type hookup without modification, meaning it’s not plug-and-play with Hammond organs. It’s a two-channel model meant for Conn organs (hence the “C”), with the rotary channel carrying the flute ranks and a stationary channel for the strings. It’s also a one-speed job, with no slow speed like the canonical models have. Hence it needs either a complicated and expensive motor conversion or a simpler, almost-as-expensive, not-as-good motor controller to get the de rigueur chorale function. With the proper modifications, it essentially becomes a 147, albeit with tube rectification and 35 watts of power instead of 40. Certainly nothing I wasn’t willing to undertake, but my nose for deals wasn’t quite twitching yet.

I kept my eye on it, because it seemed to be, to borrow a Conner O’Malley turn of phrase, right in my Q zone. An obscure model with enough issues to keep the amateurs and persnickety collectors at bay, but easily—for me—fixed up into a prime-time player. The price dropped by $50 late one night, and I moved on it. What the hell, right? The seller, a scavenger of used and vintage gear named Matt, even delivered it to me. We ended up becoming business acquaintances—I’m now his first call when something organ-ic comes across his transom. You always gotta have a guy.

Matt brought the tired old cabinet to me, and I could see that somewhere down the line an attempt had been made. The original 16-ohm Jensen woofer was long gone, replaced with a dreadful Chinese Roland unit on which someone had crossed out the “8Ω” marking and written “16Ω” in black Sharpie. Hoo boy. The amplifier chassis was dirty and rust-mottled. The circuitry had been mucked with and the tubes for the stationary channel were gone, perhaps the beginnings of an effort to convert it to a 147 configuration that was never completed. There were the telltale traces of burnination inside the chassis, evidence that someone had possibly tried to run it on a 147 hookup on blind faith. Fingers crossed the transformers were okay. The cabinet was well scratched, and a chunk of veneer was missing in a very obvious place above one of the front top louvers. This was definitely in my Q zone.

It did have a good Jensen horn driver, a structurally sound cabinet, and no missing parts. The horn rotor even still had its diffusers. I set to work rehabilitating the sad specimen, starting with the conversion to two-speed operation. A lot of people will just toss a motor speed controller in and give ‘er all the way, but I can’t, at least not on my personal rigs. Controllers just don’t give the right speed and acceleration characteristics to my ear, even when adjusted. The pulsed AC from the controller also makes the motors rumble slightly when running on slow. I’m a proponent of using original two-speed motor stacks whenever possible. This means sourcing salvaged motor stacks, and routing out the lower shelf to accept the new motors. But I had a hell of a time finding good motor stacks for this one, generally a hit-or-miss proposition anyway. All I could find were ones from later models that use a shorter fast motor that doesn’t have the right amount of torque, messing up the acceleration times. I’d start with the shorty units and replace the fast motors when I could find some.

I sorted out the amplifier, cleaning up the old kludges, wiring it for standard 147 operation, replacing the electrolytic caps, and installing an EIS solid-state relay as I always do. I replaced the stock Amphenol input plug with a locking connector. I cleaned it up, and enameled the rusted gray transformer bell covers in a matte forest green to match the label and nameplate. I thought it looked rather smart.

The cabinet was almost rough enough for me to want to strip it down and refinish it, but why do that when I could save some time and toss a bit of Craftsmanship in a Can on it instead? A few swipes of Howard Restor-A-Finish and a dose of Feed-N-Wax made it passable, with enough patina to tell a story without being offensive. Standard mechanical procedures applied. Clean the cabinet and rotating assemblies out thoroughly, rebuild the “new” motors, lubrication, replace the old bearings and rubber fittings, new bass rotor scrim cloth. I had a woofer built by Indiana’s Weber Speakers, a faithful reproduction of the original Jensen P15LL.

When I got it all put together, it sounded beautiful. It has more inner detail and complexity than either my 147 or 31H Tallboy, without the excessive harshness that the former can have when pushed to the limit, nor the destructive lows and indistinct highs of the latter. There isn’t much overdrive, but what is there is smooth and dignified. It draws me to play. When it’s behaving itself, anyway.

Like the beguiling sirens of the sea, this 51C has proven itself a treacherous and fickle mistress. Even though I rebuilt it to my usual rigorous standards of quality, there’s been a steady cavalcade of gremlins plaguing the cabinet forcing me to open it back up repeatedly. First, the upper motor stack. I had swapped the “shorty” fast motor for a full-sized one I found online, but didn’t realize that the motor was meant for another model cabinet and thus had a different shaft length. This required some deft Dremeling to cut the shaft and give it the right flat section so it would work in a standard stack.

With the proper-sized motor in place and everything running, almost immediately the horn rotor started to lose torque and slip while on slow. I thought I’d set the torque wrong, but adjusting that was only a temporary solution. I then discovered oil on the rubber tire, but figured it was just a bit of excess from assembly. When it kept happening after thorough cleanings, it became clear that the fast motor’s lower bearing was leaking and the oil was being thrown onto the tire by centrifugal force. The bearing plate was, therefore, toast, and had to be replaced.

Then the lower rotor started slipping on slow too. That, however, wasn’t entirely unexpected. See, normally on the lower slow motor, there’s a small plastic oil catch flange that slips onto the shaft just above where it engages with the rubber tire. Keep in mind that on the lower stack, the slow motor is above the fast motor—vice versa on the upper stack. In case the slow motor leaks any oil from its bearing, the catch will, as you might have guessed, catch it and fling it away before it causes slippage between the shaft and the tire. This set of motors was missing the oil catch. Not a huge deal, since you can make your own with a felt washer of sufficient size. I, however, didn’t have any on hand, so I took it on faith that the motor would be oil-tight after a proper servicing. As luck would have it, it wasn’t, so I had to improvise. Gluing together several paper punchings meant for a Fender Rhodes piano action made a stiff and absorbent washer that fit tightly onto the shaft. Problem solved.

Then, when running on fast, the cabinet developed a knocking sound. This turned out to be a too-loose lower belt, causing the belt to slap against the track in which it runs. I tightened the tension, but it kept loosening. Again, this was admittedly not totally unexpected. In a two-speed Leslie, tension is kept by pivoting the lower motor stack and tightening a toothed washer that bites into the wood shelf that the stack sits on to hold everything in place. I had no such washers on hand, and the regular washer I used was eventually loosening its tenuous hold on the shelf. I’ll either get some toothed washers in stock or just keep re-tensioning the thing.

There was also the loud farting that would happen on certain low notes. Not from me, but the cabinet. It turned out to be the badly dry rotted and cracked 6×9 flute-channel speakers on the side of the cabinet resonating and flapping around. Eighty-sixed those, and now the bass is clean. However, now it seems that the Jensen horn driver is starting to fizz out on certain notes, and will likely be replaced soon.

I occasionally worry that I’ve been saddled with an albatross, a shit pile, a lemon that will just continue to cause grief and inconvenience. But I always come back to my senses. It’s a Leslie, after all; there’s not much to it but a few belts and bearings. There are only so many kinks to work out. And even though this 51C has been as high-maintenance as a 50 year old Alfa Romeo, it’s found a permanent place here. I love it. Because not only does it sound beautiful, but the inordinate amount of sweat equity I’ve needed to put into it has ultimately brought us closer.

I opened this by asserting that we, implying everyone, always fall for the ones that hurt us. But in reality, at least when it comes to the instruments and machinery of our lives, it takes a special species of nut to not only tolerate, but embrace repeated failures and frustrations. Most folks can’t be bothered. Me, everything bothers me anyway. I’d be in the wrong business if that were a problem. It’s why people continue to buy boats and British cars and musical instruments from before the Clinton era. They—we nuts—love the foibles. Perhaps more accurately, the foibles teach us, they make memories, and lend humanity to the inanimate. We relate. We commiserate. Perfection is boring. Who ever wrote verse or song on living the Beaver Cleaver picket-fence suburban dream except in condemnation? With no low, there is no high. With no to, there would be no fro. A toast, then, to that night when the stars align, the AC power is clean, you’ve got a moment to yourself and the rig just sounds better somehow; and equally, to when the weight of the albatross is heavy around the neck and anything that can go wrong, is.

Author: Bunny Butler

I'm the last of the good old-fashioned steam-powered trains.