Hammond-Leslie switch wiring

Hi All,

I own a Hammomd RT-3 and a Leslie 122 that live at a studio nearby. Apparently, they had an accident and broke off the half moon switch. I just found this out and I need to use it tomorrow - does anyone know how that switch is wired? Can I replace it temporarily with a spst or dpdt toggle just to get through the session?

Thanks,

http://images.google.com/images?q=leslie%20switch%20diagram&hl=en&lr=&rls=GGLD,GGLD:2005-16,GGLD:en&sa=N&tab=wi

http://www.captain-foldback.com/Leslie_sub/tips.htm

does this help?

Seth,

The Coolest looking mod for the Leslie switch is the one that Jon Lord had done, which was a 3-position Strat switch, milled into the blank plate to the left of the bottom key. That way it won't get broken off going through doorways or (in his case... repeatedly) getting a flightcase lid lowered over the organ.

It also allows the middle position to be used as a "stop motor" position, if needed. Any guitar builder should be able to do it, and -believe me it really looks awesome! -Plus if the switch ever mafunctions, you can buy replacements anywhere in any city in the US that has a music store... try that with an original Leslie switch!

:thumb:

Keef

http://www.dairiki.org/HammondWiki/HalfMoonSwitch

http://www.dairiki.org/HammondWiki/Leslie147Hookup

http://theatreorgans.com/hammond/faq/hammond-faq.html
this is a good one!

Best replacement is a Fender-style guitar switch. Try to find a two position one, although a three-position would work. Wire it up like a standard on/off switch. That's all there is to it.

Another temporary fix: I learned this from Joey DeFrancesco, who hooked up my rig wrong (I wasn't there at the time due to another engagement) and fried the relay in my 122 (which means no control over the motors). He simply took an extension cord, plugged one end into a power strip with a switch and the other end into the motors and voila! Use the switch on the power strip and you get off and the fast speed. No chorale, but it's not that important. If you're on the gig (or under the clock) and the relay goes out, it's a quick fix.

:thumb:

Thanks very much everyone. I really appreciate all your help.

:thumb: :thumb: :thumb:

The interface I have is one that has two toggle switches on it, one for fast and slow, and one for leslie or hammond tone cabinet. I can't seem to find a schemo for that unit. I ran a jumper from it to the half moon switch and put tape over the other switches. I don't have a hammond cabinet, the switch is in a stupid place, and I'd reallly just like to eliminate that switch and use the half moon only. Does anyone know what that interface model is called or have a schemo for it?

Thanks

I figured it out - it's called a 1622 interface and I can just eliminate the other switch and wire the half moon switch straight to the terminals inside the organ.

Yeah, you can do that. That'll work just fine.

The only Hammond cabinet I like is the PR40. I just picked one up for $100 and used it on our last recording in conjuction with my 122. All I can say is "holy shit!" The bass is ferocious. It's the best organ bass sound I've ever heard. And it was just mic'd up with a single U87 going through a Neve 8068 console.

The PR40 has 40watts going to two 12" speakers and two 15". It's really incredible sounding with the pedals.

[quote author="b3groover"] And it was just mic'd up with a single U87 going through a Neve 8068 console[/quote]

ha!

just...

I've got an OT leslie question. I've got a really crappy mid 70' hammond (all transistors-sounds like crap) but it was given to me free along with what I think is a nice sounding leslie. It's not one of the expensive models. It only has one speaker and no control for speed. I was plugging my guitar into the line-in on the hammond and then going from into the leslie from there. I seem to recall that the leslie amps are already recieving an amplified signal from the hammond. Is that true, or can I mod the leslie amp to just take my guitar input (and how?) I don't have the amp in front of me, but I remember it using one 12ax7 and 2 6L6's. It was a great clean tone for the guitar.

Joel

Leslie's have a preamp stage. That's what one of the 12ax7s is probably for, depending on the model. If you can get the model number, then you should be able to find a schematic. They run on standard AC and again depending on the model some have balanced inputs.

There are a few companies around making "Leslie Combo Pedals" which do exactly what you're talking about but they are pricey. My guess is that it wouldn't take much of anything to DIY.

I understand there's a preamp stage in the leslie. What I'm wondering is there a first preamp stage in the hammond itself?

Thanks!
Joel

A long time ago I was doing some Leslie switching mods for a friend of mine - "stop" position, but with sensors to make it stop in the same direction every time. I think I've built maybe 5-6 of those, and every 5 years I get asked about it. One of these days I ought to figure out how to do it in a microcontroller or one of those Stamp or pic chips.
In general you can easily replace the noisy switching relay in the Leslie with a homebrewed solid state relay circuit, and then you can ditch the Leslie amp and run the cabinet from an external amp if you want. Kind of fun to run bass guitar through a stopped Leslie since the cabinet has such a nice bottom end.a


I recently dug out my file on that stuff, and I've got a schematic or two on the switching parts of some of those preamps, hand-drawn. Or just look up Goff Professional, those guys have been the source for a long time now.

[quote author="Mbira"]I understand there's a preamp stage in the leslie. What I'm wondering is there a first preamp stage in the hammond itself?

Thanks!
Joel[/quote]

Yes, but the preamp in the Hammond basically brings the level of the Hammond pickups up to roughly mic level. The preamp in the Leslie brings it to roughly line level.

I think.

[quote author="b3groover"][quote author="Mbira"]I understand there's a preamp stage in the leslie. What I'm wondering is there a first preamp stage in the hammond itself?

Thanks!
Joel[/quote]

Yes, but the preamp in the Hammond basically brings the level of the Hammond pickups up to roughly mic level. The preamp in the Leslie brings it to roughly line level.

I think.[/quote]

Isn't it basically line-level at the G-G terminals on the console preamp? That's where you attach a resistor network to get a guitar-level output, anyway.

Ah, you're right. So why does the Leslie have a preamp stage?

[quote author="b3groover"]Ah, you're right. So why does the Leslie have a preamp stage?[/quote]

Because it still needs to crank the signal up a bit to drive the power tubes, and of course to do the phase splitter to drive a push-pull configuration.