A Hammond conundrum

[ZeroZero]

Hello all,
I have three Hammond organs An A100 wired into a Leslie 700 via a 9 pin cable, an M100 with no Leslie connector and a digital Hammond SKX (with an 11 pin output). I have another "frankenstein" Leslie made from parts also with a Nine pin connector. I have two spare cables one 9 pin and one 11 pin.

I should like to plug my SKX into a Leslie - probably the "frankenstein". Maybe get the M100 connected too. There is incompatibility between nine pin and 11 pin (obviously).
Looking online the adapter cables are very expensive ($350-450) - more expensive than my Leslies. I am wondering if there are any other solutions - perhaps taking out the female connectors from the Leslies and replacing them with 11 pin females. I am sure it is probably not that simple.
What would be the best way please.

Z

[enor]

It's not quite that simple.

Both the 11-pin and the 9-pin system switches speeds by grouning either one pin for chorale, or the other one for tremolo. So far so good, a simple adapter cable appears to be able to do the job. And indeed, if the organ was an older type with a simple mechanical switch or a relay to do the switching, an adapter cable would work just fine.

But, with the newer organs that's not the case. The Leslie switching isn't done with a "dumb" switch, instead there is circuitry of different designs in them. Details can vary between brands, but the main thing is that they all incorporate something else than a normal relay or switch, since the speeds can be controlled either by switch, foot pedal or via MIDI.

So, what's the problem with building an adapter cable? It's a less obvious issue, but never the less problematic. In the 11-pin system, the "switch" connects the ground leg of a positive voltage. In the 9-pin Leslies though, the "switch" connects the ground of a NEGATIVE voltage. This is no problem whatsoever if the switch is something mechanical (like a standard halfmoon for instance) but in the modern clone organs, it plain does not work since the current thru the "switch control" part of the circuit flows in the wrong direction when a modern clone organ is connected to a 9-pin Leslie.

So, just changing the connector isn't enough - to truly convert a 9-pin Leslie to 11-pin you need to either modify the control board in the Leslie (you probably don't want to do that) or add in a couple of relays in between organ and Leslie to make the organ "see" the right type of load.

[ZeroZero]

I think I shall get a tech in to do this, my soldering is like Laurel and Hardy's cake making, Many thanks anyway