A100 changing from 251 to 147 hook-up

[fazeka]

Hi all,

I have an A100 currently connected to a Leslie 251. I can't remember the hook-up kit used (#253?) but I believe it is wired correctly.

My current situation is that I have an 147 amp I want to use with the A100 so I can easily also use the Leslie with an electric guitar (I have a Trek II UC-1A preamp).

My background: I have some experience with Leslie hook-ups as I wired this particular A100 to my 251 about 8 years ago. I also had an M3 I wired up to a[nother] 147 prior to that.

This posting is more of a series of questions about Leslie hook-up parts understanding and sourcing more than anything else.

1. I'm assuming I can swap out the 251 amp for a 147 amp and all the connections for the motors and the speakers (except the 251s 6x9s) will connect properly with the 147 amp. Yes?

2. Is there going to be any issue with the A100 reverb amp not having a load when the Leslie is switched in via the "echo" position on the M/E/E half-moon? If there is, I assume I can simply disconnect the amp (I don't need reverb)?

3. Do I need a different M/E/E switch? It appears that the M/E/E switch for the 251 (#53-3, switch #729-3) is different than with the 147 (#26-3, switch #3H-5)? If so, is there a current source for this switch or a non-Leslie (i.e., manufacturer) part number I can search on (e.g., http://www.bunkerofdoom.com/xfm/centralab/021.jpg)?

4. Do I need a new switch for the tremolo/chorale switching? Can I use my existing one? Appears to be the same (#429-1) and merely an SPST switching?

5. I believe I need a 26-1 console connector chassis to replace my 53-1?

6. I'd rather not have to use parts (plugs, switches, etc) from my existing 251 hook-up to build one for the 147 hook-up (just in case I ever decide to go back to the 251 amp, it is just a matter of a simple physical swap rather than soldering/unsoldering pieces). And I know vendors like Tonewheel Hospital etc. source the complete kit but I am fine with sourcing parts piecemeal to save a few $. 26-1 console chasses are relatively easy to come by but not so much the M/E/E half-moons with the plugs. Is there a current source for the 5-pin plugs for the 26-1 sockets? What was the original vendor (Amphenol?) and part numbers for these plugs?

7. Is there anything I have missed and/or any harm or damage I will be creating?

Cheers,
Chris

[muckelroy]

I have an A100 currently connected to a Leslie 251. I can't remember the hook-up kit used (#253?) but I believe it is wired correctly.

If you bought a Leslie 8253 kit, yes. Refer to the instructions to verify what you have: https://www.fishorgans.com/leslie_ki...or_Hammond.pdf

1. I'm assuming I can swap out the 251 amp for a 147 amp and all the connections for the motors and the speakers (except the 251s 6x9s) will connect properly with the 147 amp. Yes?

Yes

2. Is there going to be any issue with the A100 reverb amp not having a load when the Leslie is switched in via the "echo" position on the M/E/E half-moon? If there is, I assume I can simply disconnect the amp (I don't need reverb)?

It needs a load when in Echo. That is why the 011874 box contains two 8 ohm dummy load resistors. Or if you don't wanna send reverb to the 147 that simplifies things. Leave reverb hooked up to its speaker and leave it turned down all the way if you don't want to hear it. Or disconnect the reverb amp, but it's soldered in throughout, so that is up to you.

3. Do I need a different M/E/E switch? It appears that the M/E/E switch for the 251 (#53-3, switch #729-3) is different than with the 147 (#26-3, switch #3H-5)? If so, is there a current source for this switch or a non-Leslie (i.e., manufacturer) part number I can search on (e.g., http://www.bunkerofdoom.com/xfm/centralab/021.jpg)?

If you are using an 8253 kit, you absolutely have a different M-E-E switch than most kits have. I don't think you can use that with a 147 without significant modifications to the wiring inside the switch. You should just find a 3-wire M-E-E switch like what's offered in the Leslie 7271 kit. They are actually a lot easier to find than the 8253 type M-E-E switches which have 5 poles and 7 wires coming out of them.

4. Do I need a new switch for the tremolo/chorale switching? Can I use my existing one? Appears to be the same (#429-1) and merely an SPST switching?

Not really, no. I suppose it is possible to wire up a single half moon tremolo switch to both a 8253 box and a 7271 box, but you'd have to be very careful in doing this.

5. I believe I need a 26-1 console connector chassis to replace my 53-1?

I don't know what 53-1 is, so avoid making up numbers. If you have a Leslie 8253 kit, you have a 011874 console connector box. The 7271 kit uses a 027011 console connector box, and it is different. There is no dummy load inside the 027011 box (AKA 26-1) because the dummy load is inside the 147 amp instead.

6. I'd rather not have to use parts (plugs, switches, etc) from my existing 251 hook-up to build one for the 147 hook-up (just in case I ever decide to go back to the 251 amp, it is just a matter of a simple physical swap rather than soldering/unsoldering pieces). And I know vendors like Tonewheel Hospital etc. source the complete kit but I am fine with sourcing parts piecemeal to save a few $. 26-1 console chasses are relatively easy to come by but not so much the M/E/E half-moons with the plugs. Is there a current source for the 5-pin plugs for the 26-1 sockets? What was the original vendor (Amphenol?) and part numbers for these plugs?

I don't think you'll have much difficulty finding a 3-wire M-E-E switch that still has the 5 pin male EBY connector on it. As for leaving the organ "equipped" for both hookups, you can do that, but you should install two separate 6 pin sockets on the organ, one for 6C and one for 6W hookups, and LABEL EXTREMELY CAREFULLY AND BOLDLY each one. I'd go so far as putting painter's tape or fashioning some type of cover over the unused hookup kit if this is going to be toted around to gigs in dark places.

7. Is there anything I have missed and/or any harm or damage I will be creating?

I think you are on the right track. Be careful. Dress all your wires neatly and mock things up before soldering. Good planning is your friend with this approach.

EDIT: If you install both kits in tandem, you'll have to think about what you'll do when in "147" mode. That's actually a can of worms, especially if you have two M-E-E switches. (Not to mention, confusing.) Most people simply have a speaker mute switch that switches between speakers and a dummy load installed somewhere. The Leslie output is always active. So, chew on that for a while and I think that's a better option for you.

[fazeka]

If you bought a Leslie 8253 kit, yes. Refer to the instructions to verify what you have: https://www.fishorgans.com/leslie_ki...or_Hammond.pdf

Unfortunately, I never bought a complete kit, I pieced it together based on the research I did then (8 years ago) using original parts...

It needs a load when in Echo. That is why the 011874 box contains two 8 ohm dummy load resistors. Or if you don't wanna send reverb to the 147 that simplifies things. Leave reverb hooked up to its speaker and leave it turned down all the way if you don't want to hear it. Or disconnect the reverb amp, but it's soldered in throughout, so that is up to you.

To be clear, currently with my A100 connected to my 251, I have no need to have a dummy load on the reverb amp as it's output is sent to the 251 6x9s. So, I assume the 011874 box is part of the hook-up for an A100 to a 147?

I will probably end up leaving the reverb amp hooked up to its speaker and leave it turned down.

If you are using an 8253 kit, you absolutely have a different M-E-E switch than most kits have. I don't think you can use that with a 147 without significant modifications to the wiring inside the switch. You should just find a 3-wire M-E-E switch like what's offered in the Leslie 7271 kit. They are actually a lot easier to find than the 8253 type M-E-E switches which have 5 poles and 7 wires coming out of them

Thanks for the confirmation!

I suppose it is possible to wire up a single half moon tremolo switch to both a 8253 box and a 7271 box, but you'd have to be very careful in doing this.

Don't plan on having two different hook-ups for this organ, I think if I can just use the 147 with it, that will be just fine!

I don't know what 53-1 is, so avoid making up numbers. If you have a Leslie 8253 kit, you have a 011874 console connector box. The 7271 kit uses a 027011 console connector box, and it is different. There is no dummy load inside the 027011 box (AKA 26-1) because the dummy load is inside the 147 amp instead.

FWIW, I'm not "making up" numbers. A 53-1 chassis box is part of the 253 hook-up kit for the 251 (from the manual):

https://i.imgur.com/hk3n4G3.jpg

https://i.imgur.com/HcXTi6n.jpg

I think the issue here is that the part numbers you're referencing have changed from the 60s hook-up kits and the parts that I acquired and reference are based on those older part numbers. There is no right or wrong numbers, but they are different. And I think there also may be an assumption that I am using parts that are reflecting the newer numbering scheme and that I used a complete kit when in fact, as stated above, I pieced it all together. My apologies, I should have clarified that in the original post.

I don't think you'll have much difficulty finding a 3-wire M-E-E switch that still has the 5 pin male EBY connector on it.

Let me clarify: yes, maybe not difficult but an incomplete switch may save me some $$$ if I can hustle parts for it. Really, all I need is the lever switch itself (part number, anyone?) and the 5-pin plug... I guess I could figure out which switch part number if I study the schematic long enough, unless the switch was a custom part... although I'm also not sure if it's MBB or BBM???

As for leaving the organ "equipped" for both hookups, you can do that, but you should install two separate 6 pin sockets on the organ, one for 6C and one for 6W hookups, and LABEL EXTREMELY CAREFULLY AND BOLDLY each one. I'd go so far as putting painter's tape or fashioning some type of cover over the unused hookup kit if this is going to be toted around to gigs in dark places.

Not going to be equipped for both hookups, as above: I want it equipped only for the 147. But I want to keep all the parts in case in the future I sell or change my mind and want to go back to using the 251...

I think you are on the right track. Be careful. Dress all your wires neatly and mock things up before soldering. Good planning is your friend with this approach.

Agreed. That is why I am posting on this (and other) forums!

EDIT: If you install both kits in tandem, you'll have to think about what you'll do when in "147" mode. That's actually a can of worms, especially if you have two M-E-E switches. (Not to mention, confusing.) Most people simply have a speaker mute switch that switches between speakers and a dummy load installed somewhere. The Leslie output is always active. So, chew on that for a while and I think that's a better option for you.

I'm not planning on installing both kits in tandem. Too much confusion/hassle.

Thanks,
Chris

[muckelroy]

It's almost impossible to buy complete vintage kits unless you find a retiring organ tech, or a closing parts warehouse with NOS surplus.

The images you referred to are from the 251 manual. I prefer the Leslie instructions here: https://www.fishorgans.com/leslie_ki...or_Hammond.pdf

I suppose they do say 53-1 on the box. I have not seen one in person before. Rather the last one I did was a 251 which got converted to a 147, which is a different job entirely.

For the most part, anything in a Leslie hookup kit can be constructed from modern day parts if the circuit is followed. I recommend buying a used M-E-E switch, but you're asking for modern part numbers for switches, and that's information closely guarded by those who sell and market half-moon switches. I've seen various vendor names mentioned on the forum before, though.