Hammond S6 Chord Organ Part 5: Stuck in the (chord) Matrix

Well, I’m near the end of this saga. I washed the plastic chord button assembly and put a little silicone lube in each of the 96 holes. Can you imagine washing the knobs on a receiver with 96 knobs? Typing that reminded me I cleaned the knobs and slider caps on an old Soundcraft mixer that had maybe to 200… Maybe that’s why they called it the 200!

I also took A LOT of it apart last night and a little oil here and there has everything returning as it should. I spent so much time on this I didn’t get to the coupling caps or fuse adding. Will try and do that today.

I needed to get this assembly out to see what the mechanisms looked like so I would know how to proceed with lubrication or adjustment. The terminal strip on the far right is broken between lower 3rd and 4th connections – I think the power supply gave it a hard yank when it got free. Didn’t interrupt anything so I am going to ignore it.
Only 4 screws to get in here, but finding which 4 meant undoing a bunch. Those two sets of 12 metal leaves running vertically in this picture are the note triggers for the two pedals. I made them as parallel on the pivot shaft as possible and put a little oil on the pivots. That brass top hat looking thing sticking out of the center contact strip is there so you can wiggle it to clean contacts without taking anything apart.
Some spindle oil in a flux bottle was on hand so I used it. I put a line on either side of the little actuator where it comes through that comb assembly. Everything now pops back in to place immediately when a chord is played. Yay!

And so finally, coupling caps replaced – 2x .047uf 400V MKT caps by ERO from the early 2000s replacing 2x original .047uf 300V caps from the mid 1950’s. Pulled the fuse holder from my big bag of random NOS fuse holders and wired it into one leg to the power switch. Found a 2A slo-blo that I installed. Checked for short – found none, so I powered on. Working well for now. All done!

They look out of place, but they are very high quality ERO MKP caps.
 Fuse install looks factory and period correct if I do say so myself. This was an NOS fuse holder I had in a giant bag of NOS and used fuses I picked up at an electronics swap meet years ago.
So here’s a question. Do I just put either side of a standard cord on pins 2 and 4 of that 5 pin socket and I’m in business? Gotta get the PR40 in the mix. My reverb quota is off this month.

A response I got that is not here: “A standard cord would be fixed in place, and run through an added fuse (and local switch if needed) and go to ‘2’ and ‘4’. Hopefully your heater voltage is then within spec from your local mains voltage. Do you also have a protective earth?

The chassis ground would also need to be linked over to provide a reference to the speaker output winding of the S6. Not sure how significant a hum loop issue you will get from two mains connections. You may need to google about the reverb control function, and how that interacts with the 30V bias supply.

The PR40 could do with a bit of fault protection imho, as a B+ level fault could cause some collateral damage.”

Gonna worry about the PR40 when I have space to set it up – hopefully sometime in the years to come.


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