New (to me) Conn 646

[Conn646-guy]

New to the forum here, and happy to have found you all. Last Friday I adopted a Conn 646 (circa 1983-4) 2 manual, 32 pedal theater organ, but the organ movers weren't kind as they wrestled 440lbs up to stairs. I'm seeking a service manual and wiring schematic to empower the reluctant and remaining service people in the Chicago area as none that I've spoken to yet want to touch the organ without some documentation in hand (and none have any). In addition to some broken keys, I'm getting a loud hum/buzz put of the main amp, but all sounds and effects otherwise survived.

I have a willing and enthusiastic teacher ready to convert this classical organist into a theater organ guy, but nothing is happening with missing keys and a loud buzz. Any leads would be appreciated.

[myorgan]

Oh, no! Another one bites the dust-these classical organist converting to theatre.;-) Welcome to the Forum!

There is a brochure in the Galleries here: https://organforum.com/gallery/thumb...bum=128&page=9

You can find replacement keys on *Bay, but make sure you check with the techs here before you buy any. There are at least 2 different types of keys. I can't remember seeing another brand organ with as many broken keys-almost ¹/₂ the Conns I see for sale have at least 1 or more broken keys.

Another location to search for a manual is at Barton Theatre Organs: http://barton.theatreorgans.com/adsearch.asp. I've seen several Conn Service Manuals listed there from time-to-time.

I hope that helps get you started. Again, welcome to the Forum, and I hope you continue to participate here after your answers are received.

Michael

[Silken Path]

Hi, Guy. Well, that answers something that I've wondered about - if the 32 key pedal boards looked like the chopped off 25 on models like my 643, only the REST of it. :)

Congrats on the new Conn. It's a beauty. Pictures of it with the top tilted back would be welcome. Mine has the vinyl rods and whiskers for keying, has a bank of oscillators hanging inside the back, and has the ICs in a box with a dire warning placard. The organ also has a nice thick back.

Is the 646 very similar to a 645? I do see a service manual for one of them at, oddly enough, Amazon.

https://www.amazon.com/Deluxe-Theate.../dp/B00R4WM9RY

[myorgan]

Lamar,

I asked that same question in another thread, and the response received is that the two models are VERY different. Different technologies inside.

Michael

[Silken Path]

Michael - Thanks. But not knowing is why I described my 643 in detail. So he could tell if the model was similar. I do have the manual for a 643, for what it's worth.

[edkennedy]

Michael is right. The 645 (I have one) uses tubes for oscillators and for the power amplifier. The 646 is all transistor. It looks, however, that this is a pre-Kimball organ, and the overall wiring layout may be similar to their older organs. If the layout is similar, then we can probably help you if you want to check some things out yourself.
Please post some pictures of the inside of the organ.
First from behind (Yes, that means pulling that 400lb beast away from the wall and removing the back). While you are back there, look for the power amplifier, probably at the bottom of the organ, and make sure the input wires are fully pushed in. Your buzz might be as simple as a loose connector. The Leslie motors and bearings probably also need to be oiled. I can get the instructions from my manual if you want to do that yourself.
Next lift the top. If it won't lift up, look for a lock screw on each side reached from behind, and just below the top lid. They don't have to be taken all the way out, just loosened about 10 to 15 turns.NOTICE - This is again assuming that your case is made with the same lid locks as mine. It may not be the same. Once you get the lid up. the keyboards are held down with spring catches. Simply lift up the upper keyboard by lifting at the cheek blocks. it may be really stiff if it hasn't been lifted in a long time. take a picture of the key contacts and the top of the keyboards. That will tell us if your organ uses the same keys as all the older Conns.

[edkennedy]

I WAS WRONG! I looked at the 646 brochure in the gallery here. Your organ was made after Kimball took over Conn organs. That means we really need pictures to determine if your organ uses the same key caps as the older ones.

[Silken Path]

Hi, Guy - Well, the consensus is that you should show some us pictures - one detail with the top tilted back, and one with the back removed. Isn't it cool that Ed K., me, and now you all have a different generation of two manual Conn theater organs?

About the buzz, I agree that checking the connections on the amp, if it's in the lower left as viewed from the back location. If it's not there, I'm lost. Then I'd look around the expression pedal wiring to see if anything is going on there.

And it's great to have a classical organist with an old theater organ from a company that made their millions providing band instruments. :)

[Silken Path]

Guy, I forgot to mention that Deoxit D5 or CRC QD (from NAPA auto parts) can be sprayed directly on pots like on the expression pedal and below any knobs, etc. There's also a Deoxit F5 that can sprayed on slider (channels) that I've had good success with.

[Ed 646]

I am new to the group. I am in the greater Chicago area and have the manual. I would let you copy it, but will not let it out of my possession. I need it to keep my 646 running.