The original Leslie rotating speaker system was packaged in a number of ways. If you're a guitar player who writes and records, and are curious about adding the rotating magic to your tone, this information is for you.
|Rear of Leslie 147 system with covers removed for clarity
What is the Leslie sound? At its heart the sound of a Leslie speaker is a physical form of modulation, there are two speeds, fast and slow. The transition between the fast and slow speeds is one of the best Leslie effects.
AND THE AWARD FOR BEST LESLIE FOR GUITAR GOES TO: Vintage 147
- Large Furniture Grade Cabinet
- Fat Bass Sound
- Unique Treble Response
- Tube Amp Tone
The 147 was originally designed for unbalanced instrument signals from portable organs of the 60's and while it may look similar to its cousin, the model 122, they're very different (the 122 is designed for balanced audio input from a direct-connected Hammond organ).
The complete 147 for guitar players consists of three components:
|Leslie 147, Brown Cable and Combo Preamp
#1 The Leslie 147 instrument speaker system, complete with 40 watt tube power amp, two-way crossover, horn speaker with custom Leslie driver and 15" bass speaker.
#2 The BROWN Leslie cable (which inputs power, high low speed switching, and audio). Originals were typically 30 feet in length. It's stiff multi conductor wire and it should never be bent at hard right angles. Treat this cable with great respect, don't abuse it.
#3 The Combo Preamp. After trying everything I could think of I came back to the classic Leslie Combo Preamp for instrument sound input. These are starting to get rare and are commanding higher and higher prices in the used market. Still the best and built like a tank. Try and find one that has not been under water lol.
HOW TO CONNECT THE LESLIE SYSTEM
The Combo Preamp gets plugged into the wall for A.C. power. It is best to have the combo preamp turned off or unplugged from the wall while connecting the thick Brown cable connections. The On-Off switch on the combo preamp is also the On-Off control for the connected 147 amplifier and rotor motors.
|Instrument Inputs on Combo Preamp
The combo preamp has two identical instrument inputs which each have their own volume control. These preamplifier circuits were designed to handle a wide range of unbalanced musical instrument sources from Vox Continental organs to Les Paul guitars.
The thick Brown cable plugs into the Combo preamp. The other end of the thick brown cable connects to the multipin connector on the power amplifier which is located in the bottom of the 147. The connectors on the ends of the Brown cable are not only old school, they're OLD. Treat them with great respect and never force them, they are keyed and only plug in one way.
WHY THE 147 LESLIE SYSTEM IS THE BEST
I've owned both the 145 and the 147, I like the 147 better. The 147 is larger and has more "whomp" in the low frequencies than the shorter 145 model. The 145 and 147 are basically identical. The 145 features a shorter cabinet which reduces the bass output slightly compared to the taller 147.
|Leslie 147 Tube Power Amp, wiring shown is stock
The stock 40-watt tube amp in a 147 is a very basic circuit, powered by a beefy pair of 6550 power tubes. There is a master volume control on the power amp. You can get a cool crunch tone by running the Combo Preamp volume wide open, reduce the Master Volume to keep from damaging your hearing. The Master Volume control on the 147 amplifier is a powerful tone modifier.
The High-Low (Fast or Slow) speed control is located on the Combo Preamp, a pair of lights are provided, one for high and one for low speed indication (the lights are handy if the Leslie is in another room or location physically away from the player.
The Leslie speaker system is the original form of modulation, before digital, before phase shifters, before flanging, these great behemoths with their spinning speakers were giving the world unique modulation effects that are often imitated but have never been matched by other electronic means.
THE SOUND YOU'VE HEARD ON COUNTLESS CLASSIC RECORDINGS
You've been hearing the Leslie speaker system for years, your ears are already in love with the tone, you just may not have known it. Everyone from the Beatles to Joe Bonamassa has used Leslie speakers to add motion and enhance their sound.
WHAT ABOUT A NEW LESLIE?
There are new Leslie speaker systems being made. These new designs use different amplifier circuits and different mechanisms to spin the upper and lower rotors. This also means they sound different than the old classics like the vintage 1971 model in my studio. Newly built Leslies sound better than digital simulators but not as good as the vintage models.
If I did not have my vintage 147 Leslie system I'd be looking for one, it is one of my all time favorite instrument amplifiers. They made a lot of these speaker systems (back in the day) and todays after-market for replacement parts and repairs is very robust.
The sound of a guitar, played through a proper 147 system is a thing of beauty to behold.
Good Music To You!
©December 2022 by Mark King. It's not ok to copy or quote without permission.