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Strange? midi plan for catatonic Conn 651 w/AGO pedal

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  • Strange? midi plan for catatonic Conn 651 w/AGO pedal

    The pal who gave it to me made some snide comment about my mental condition as he drove away. So I’m sorta motivated...

    ...to create a basic, cheap, frumpy, did I say cheap mouse-driven 2-manual practice midi church organ quasi-console, sans pistons/toe studs, that’s able to drive a virtual pipe organ.

    Yes it’s hurting, btw - 2 keys broken off, soft weird cipher white noise irrespective of pressed keys, roughed up.

    Please opine on the rough and idiosyncratic (ill-advised?) plan that I’ve fixed on after a reasonable amount of research:

    1 Reread safety advice sticky post

    2 Dissemble organ above pedal area and disseminate useful parts (who wants a Leslie?!)

    3 Retain original pedalboard contacts/wiring to drive midi (is this a reasonable alternative to updating with magnets/etc?...certainly more interesting... and maintains a shred of its former electrical self)

    4 Reconfigure/refinish/paint wood frame for two “shelves” (no tree died in vain, no infernal metal keyboard stands, organ is currently residing in a cabinetry/paint shop). (Thinking off-white like some of the 651s).

    5 Retain swell pedals and get a basic Arduino-like midi solution for them (again, more fun)

    6 Put two passable 61-key consumer keyboards on “shelves” (or 3 but this is already ridiculous)

    7 Hook it up and start figuring out how easy organ playing is(n’t).

    ALL THIS...to give an ago pedal another stab at life...

    Thanks for reading and opining...and other any perpectives...that don’t refer explicitly to my mental condition.

    Conn 651 - rescued from crusher
    Yamaha C3 Walnut
    Ark full of various instruments

  • #2
    The console, the pedalboard...and someone’s practice rig I hope I can improve on.

    I don’t want to give up on it. And I’m trying to get my playing to where I can be a substitute at my church in an Allen Renaissance.

    The real question is can the existing pedal wiring dependable enough to drive midi?
    Conn 651 - rescued from crusher
    Yamaha C3 Walnut
    Ark full of various instruments


    • #3
      The Conn pedal contacts should be fine for a MIDI converter.
      You may want to keep the existing keyboards. Replacement keycaps are easy to find and change. Conn keyboards have a decent feel to them, while cheap MIDI keyboards feel really awful. That would mean quite a bit of wiring work to add the MIDI adapters to the existing keyboards.

      Alternate plan, If you know old style electronics, fix it as is and use it as is for a practice organ. I'm using a Conn 645 ( 2 manuals,AGO pedals, and 50 vacuum tubes) as my practice organ, and after cleaning the key contacts, it sounds decent and has been working reliably for several years now.
      Ed Kennedy
      Current Organ - Conn 645 Theater


      • #4
        Agree with edkennedy, Conn keyboards are decent, and probably have a better feel than a modern cheap keyboard. Maybe source a Conn manual being sold or given away for parts, and replace those two broken keys.


        • #5
          I once owned a Conn 651 that I "thought" I could use as-is to practice for church. But the voices and layout are strictly theater-style and I just couldn't get much use of it that way, even though it was in perfect working order. Finally sold it to somebody who wanted it just like it was. That was long before the VPO era, so I didn't even think about converting it into an actual classical organ. But I like your idea.

          There's no doubt that the keyboards are above average in feel and durability, and the pedalboard is very sturdy and solid. The only drawback is that the contact systems are distinctive and made for Conn's unusual keying methods. So you'll have to do some modifying of the key switch setup in order to get a one-switch-per-key arrangement that is needed to connect to a typical MIDI encoder. Not too difficult, since you'll be ripping out all the old electronics and wiring. Just preserve one good set of contacts under each manual and one set on the pedals. (The contacts at the rear may be unsuitable, as they are probably wired in some sort of weird chain. The pedalboard also has regular contacts on the front, which may be much more suitable for MIDI work.)

          If the keying rods still have that conductive vinyl mess in them, you'll have to replace that with something that conducts instantly and doesn't rot. I have used ordinary wire solder for that purpose in the past. Just get a roll of silver-bearing lead-free solder that is the right diameter to exactly fit into the groove where the vinyl was, and lay it in there. The same clips that hold the vinyl will hold the solder, and it is pliable enough to mold precisely to the rods. The only problem is attaching a wire to the solder, but very careful soldering using LEADED solder should work, as the silver-bearing solder will not melt at the low temperature used for the regular stuff.

          The pedal board itself may require some refurbishing at that age. Replace any of the upstop/downstop material that has rotted or thinned out with real felt from a piano supply house (or buy it on ebay/amazon), and do whatever is necessary to repair the mounting hardware, springs, and such, which may have broken or sagged over the decades.

          Good luck. Post your progress and let us all enjoy it with you!
          *** Please post your questions about technical service or repair matters ON THE FORUM. Do not send your questions to me or another member by private message. Information shared is for the benefit of the entire organ community, but other folks will not be helped by information we exchange in private messages!



          • #6
            Thanks for the replies and encouragement.

            Honestly I don’t have the fight for restoring the theater possibilities (though I thoroughly enjoy the music at MLB games...as I recall...).

            Also being honest I really would like having the three keybeds survive. I just never found the post that clearly described replacement of a broken key specifically on a 651. That was first thing I looked at - tried gently to pull tab at back and remove but nogo. I saw an octave of keys on ebay...I looked under at the rods and was enthralled but it all seemed out of scope. Suggestions welcome. I would love to achieve midi with the single rod solder mod or the like.

            While we’re in scope creep mode...the 52 stop tabs have a delightful form factor and deserve to party on. If I kept the horseshoe I’d have an “agnostic” midi console in theater layout. [I could separate and reconfigure them on sides like church stops but I could also do something illegal for money and get a Hauptwerk console]. Pistons sound like a reliability challenge - I suppose a retrofit or some other option is possible.

            Other adult supervision projects doth beckon - car vacuum leaks, primp/sell a 18th century Dutch antique (to create organ nook), old Emerson desk fans rewind, piano action, hk citation ii tube amp redo...and...aren’t we all writing our cantata?!

            I’ll have another hard look at the case and refinishing level of effort - surely I haven’t just talked myself out of that de minimus cheapo utilitarian approach I was firm about?

            If it all works I’ll play with the, yes, clunky pedals until I can’t stand it.

            From the heart, thanks again for chiming in, gentlemen.

            Conn 651 - rescued from crusher
            Yamaha C3 Walnut
            Ark full of various instruments


            • #7
              Conn key Removal;
              As far as I know, all old Conn keyboards are the same. To remove a key, start at the top of the keyboard, and pull out the flat brass colored spring at the very back of the key. You have to push the end down slightly before it will pull out. Now the key is loose, but it won't slide forward enough to actually come out. Lift the keyboard up, and look at the bar that goes across in front of the keys. On mine, there are several pairs of screws holding it on. Each pair has one screw in a hole, and one in a slotted hole. Remove the screws that go into the holes, and loosen the ones in the slots. You can now slide the front piece forward enough to remove the key.

              Weird cipher;
              Is it a single note, multiple notes, and in which channel? I suspect it is in the flute channel and will get worse if the sustain is turned on. If so, that is one or more flute keyer circuits not completely shutting off. If it is a overall, quiet background noise you hear with the volume all the way up, mine does that too, and probably is normal.

              Practicing on an old Conn;
              While the Conn is a good organ for practicing fingering and pedaling, the registrations sound quite a bit different from a true classical organ. For myself, I'm still having problems getting the fingers and feet to do what they are supposed to, and the differences in stop rail layout and registration are not a problem for me now.

              Ed Kennedy
              Current Organ - Conn 645 Theater


              • #8

                Thanks for input. That’s the key info I was hoping for.

                Note that amps and leslie are already carefully removed - we did that to save our backs last year, but not before firing it up. I think one of you would have heard it and said “sounds worse that it is”. But I’m vpo minded, so come get it if you want me to stop desecrating it (and I’ll find some old Moeller keys and start from scratch).

                Testing/close inspection confirms:
                • Mice have had a house party inside it (hantavirus haunted house? - taking precautions here)
                • The one stop tab I tested has passed inspection (~0 ohms) without contact cleaner which is good because they’re part of vpo plan.
                • C8 key whisker on Solo keyboard passed the 0 ohm test using top tibia buss bar (bar manually twisted, multimeter probe contacting far end of rod at left). Nice. I will test more but I see those keyboards working.
                • Some of pedal contact springs look stretched (burned?) and they all look scary. So magnets on the pedals I think is the call.
                So, I’ll test a few more things then buy replacement keys and get started. A friend gave me a Denon surround amp and some b&w speakers and sub. And I have some nice bookshelf monitor-like speakers. Feel like I’m set here for 4 channel.

                More questions:
                1. I’d like to keep the 61-wire bundles coming off each keyboard and solder the midi connections at the other “end” of these wires. As I carefully dissemble without a manual, where should I look to find the terminus for each of these key wires exiting the bundles (tone generators would be too easy!)
                2. Is it overkill to aim for a 3-manual Grand Orgue wet, multi-loop, multi-release sample of a large mechanical organ? Going for articulate, Bach-friendly, tasteful, sensible dispositions.
                3. Will Linux box be more rewarding than Windows vis-a-vis software/OS update headaches, long-term stability, and appetite for/availability of large high-quality samples at less-than-HW pricing?
                4. Other than cpu/memory/sound card or dai, what pratfalls should be avoided en route to low latency in large samples on a budget? (Starting to wonder about budget!).
                5. Should I make a church bench?
                6. And finally, on pedals...reed switch or Hall effect??

                Conn 651 - rescued from crusher
                Yamaha C3 Walnut
                Ark full of various instruments


                • tbeck
                  tbeck commented
                  Editing a comment
                  In terms of GrandOrgue samples sets, there are several nice baroque style sample sets, though they are two-manual and not particularly large.

                  From Piotr Grabowski there are three nice ones:

                  Rasczcyce - from the 1960s, Dutch builder. It has beautiful individual stops with great articulation and very nice reverb.

                  Giubiasco - from 2008, Italian builder Mascioni. Nice stop list, lots a reverb, a little more distant than Rasczcyce. Great tutti.

                  Azzio - also from Mascioni, 2016. A small instrument, with lovely voices. Very bright, lots of chiff, great articulation and lovely reverb. Beautiful sampled trems.

                  There's a new one, Obervellach from 1700 24 ranks, 2 manuals and pedal that I haven't checked out yet. The other sample sets are free, but this one is not.

                  Also check out Sonus Paradisi. Many of the sample sets are unencrypted and usable in GO if you don't mind creating your own ODF.

              • #9
                Wiring harness ... Not that easy! The existing harnesses are useless to you.

                On the Tibia stops which use the rotating rods to turn them on and off, the rods have DC voltage on them, and the fingers with the harness goes to the keyer circuits behind the manuals. The problem is that ALL the flute / tibia stops go to the same set of keyers! For example, all 3 manual's middle C key switches for 8' are in parallel and any one of them will turn on the middle C keyer. In addition to that, the 4' keys an octave below middle C also are wired to the same keyer, as are the 2' keys an octave below that, etc...

                The other key contacts won't work either for your VPO. First, the rods have a plastic covering which has some resistance in it, and the harness that goes to the fingers is again in parallel for all 3 manuals, except this time they go to the tone generators, and the output from the rods go to the voicing circuits for all the stops that are not flutes/tibias.

                So, in simple English, to use the manuals, you will be making new harnesses.

                Pedals, test the contacts before discarding them. the springs in mine look a bit nasty, but work perfectly.
                Ed Kennedy
                Current Organ - Conn 645 Theater