Connecting Leslie 700 to Hammond M3- Can it be done?

[BBmusic]

I just acquired a Leslie 700 cabinet and then read on a forum post that they are not meant for Hammond Organs. I am wondering how true this is.. Can anyone advise? Can they be married? Where might I find more information about the Leslie 700?

[tmccann]

It can be certainly done, but not sure I would do it. To start, you should get a Trek II LCO-1A crossover ($80) and install that in the 700 to make it a single channel cabinet. Then you need a 9-pin cable and connector box setup for the M3 to interface to the Leslie. The kit and switches for that run about $400 new. You can scrounge some spare parts on eBay and make your own, or hardwire it directly if you have some electronics skills, but it will still cost you some money. It's funny that a free or cheap Leslie can cost $500 to hook up, but it does sometimes! I got a free M-103, and $125 Leslie 710, and then I spent $250 to hook them up!

The 700 has a fixed bass speaker and a Rotosonic speaker. Most Hammond folks are not fans of the Rotosonic sound, and there is no upper rotating driver in this model either vs. the 710, for example. The Rotosonic takes a long time to spin up to speed as well. People say the sound is more like a "theater organ", whatever that means.

If you want a cheap Leslie, a better bet may be to wait a bit and check local adds and facebook marketplace for a Leslie 125, which show up from time to time for $100-$300. I just passed on a 125, the connector box, cable, and Leslie switches for $100. It came with a "free" L-100 organ that I didn't want to lug to the dump. 125 models have the wooden style two-speed bottom rotor and sound decent. Some folks add a crossover and sneak a small tweeter under the big speaker to get more treble. A 125 will also have a cheaper connection kit at about $250 new, and you can get used ones on eBay. The best part is once you have the 125 connector box, if you stumble upon a cheap 147 then you can plug it straight in and get rid of the 125.

If you want to study up on the connector box stuff, you can see a lot of them at https://www.fishorgans.com/leslie_kits/. When I was building my own custom box I studied the various kits there to determine what to build. Remember if you disable the internal speaker on an M3, you need to provide a load to the amp or you'll cook it.

The other thing a lot of folks say about Hammond sounds, is that any Leslie is better than no Leslie. That one is absolutely true.

[andyg]

Very easy to make a hook up kit for this one, just a few $ in parts, plus a (pricey) 9 pin cable. Most expensive parts would be the amphenol connectors and you could always choose to go non-standard on the cable, apart from the 9 pin female amphenol required to plug into the 700. The speed switching is done by switching ground from one pin to another so that switch carries no voltage or current to speak of. You don't need a half-moon. Trek II crossover is mandatory.

But paragraph 2 is the important one, the 700 just won't give you the sound. A 710 would be closer as it has the horns as well as the Rotosonic drum. The tremolo from the Rotosonic is deeper than a conventional drum, a bit more like the tremulant on a theatre organ, which is why we say it has a 'theatrical' throb to it. Ironically it IS the sound that inventor Don Leslie actually wanted in the first place!

Do read up the info on the Fish organs website, or read through the hundreds of threads on this forum about hooking up Hammonds to Leslies. A mine of information and every question you can think of has already been asked and answered.

As you've already got the 700, you could build the kit, install the crossover and enjoy the leslie sound (yes, better than no leslie!) and look around for a cheap 710. Then just swap the crossover into it and sell the 700. And you could be saving up for the 145 or 147 (or 760) that would really give you the sound you no doubt have in your mind.