OAS strikes me again - Conn 652

[Reorganizing]

It's been a couple of years since I last accumulated an organ, but I couldn't pass up this Conn for free, including three pipe speakers. The cherry on top was the included pair of Roll-or-kari dollies - I wish I'd had these years ago.
Half the keys on the accomp manual don't work, and none of the tibia stops, and the internal Leslie makes a loud ticking noise when it's running, but I'm hoping that I'll be able to get it going. Ominously, included with the documentation was an email from someone who was trying to track down some electrical gremlins in it over 20 years ago.

[myorgan]

I hope you haven't bit off more than you can chew! It looks like you have gotten a deal, as long as you can get it working. Congratulations, and keep us posted.

Michael

[Reorganizing]

As of last week I'm now fully retired, I'd been part -timing since April, so I have time, and all the equipment and documentation to try to troubleshoot this. My little Wurlitzer was far more of a basket case than this, and it's now fully functional. Shame it's not a particularly good instrument.
I may have a lot of questions to the forum in the next few months.

[tleed]

Can we be friends?

I just acquired a Conn 652 end of October. It has issues, which I've posted about a bunch since I picked it up. Most remain unresolved. It came with a silver set of pipes as well, but no apparent way to connect them to the console. There's no junction box under the key desk that I've found yet.

However, I was able to get the non-functioning onboard Leslie speaker going. This Conn is a poor design, in that it requires regular oiling of the Leslie motor, and unlike a Hammond, it's a pain to access. You have to take the back off, open a swinging panel, and then dismount the motor itself. I pulled the motor to make sure I got the oil on the bearings, because I couldn't tell otherwise. Mine wasn't rotating at all (no surprise what years of neglect can do!), but it's been running fine ever since I slathered it down. It looked to me like it has a shaft it throws to change the speed, and maybe yours is sticking or popping as it's being thrown.

Can't say as much for the electronic side of things. I have volume balance issues that I suspect are due to failing electronic parts. I also have some finicky keys, but they cleared up since I've been playing it regularly…only to get finicky again after I moved it about 2 miles.

Given that I'm in SW VA (Blacksburg) and you're in TN, we could be as close as 100 miles, or as far as 9 hours away. What city are you in? And what might it take for me to con you (pun intended) into coming to do a little tune-up on my organ? I have an external Leslie for mine, and it needs a more solid organ to drive it than my 652 is right now.

Thomas

[Reorganizing]

I'm near Nashville, so there's about 5 hours of Tennessee before getting to Virginia...I certainly don't know enough about these yet to be of much help. My internal Leslie is working well now, the noise was just a flapping belt, but I'll check the bearings before I put the back on - the low speed motor is interesting, its rotor slides in and out of contact, so i can see it being very sensitive to lubrication.

[Silken Path]

Chew away Reorg... Nice looking organ and pipes, and the Roll-o-Cari is a heck of a bonus. My Conn theater came with the top pre-loose and it flopped open when we slid it in the truck and tried to stand it up. Whoops. Anyway, it had sat since 1980 or so, so the screws were removed and left out years ago. So see if you can tilt the top unit back - it may be lacking screws, too.

I used D5 Fader lube on the key contact rods for the notes that weren't sounding and seemed to fix them. I noticed yesterday that a few of them need help again with a couple of the stops.

That's the extent of my tips for Conn theater organs.

[Reorganizing]

Mine still had most of the screws present, though it's obviously been opened up a few times before. I've gotten all of the keys to work on the top two manuals, some needed the contact gently rubbing, a couple needed bending back straight, one was distorted enough that I just bent the actuating tab on the keystick to get the operating point in the right place.
The accomp manual is another story. All the Cs are silent, and that seems to be down to a break in the loom - since it's multiplexed, one break will affect them all. If I lift the manual, it sometimes starts working. Then there are several blocks of keys that don't work, but setting "accomp to accomp 4" does produce the sound from the octave below. I suspect it's the tinned contacts on the many keyer boards.

[tleed]

So what is D5 Fader lube and where do you get it? And how do you get access to the key contact rods?

My 652 lid lifts up from the seat side. It’s hinged at the back and has an arm that will lock and hold it up. It wasn’t attached when I got it, and I didn’t notice whether it had any screw holes with missing screws or other hardware. However, I was not trying to teach mine how to do a forward roll!

[myorgan]

So what is D5 Fader lube and where do you get it?

Is it DeOxit?

Michael

[twnelson]

The 652 uses digital keying, so thankfully there's none of the old vinyl contact rods to deal with.

There's just one contact per key under each manual, which are accessed by raising the top, then starting with the Solo (top) manual, lifting upward firmly by the cheek blocks until it pops out of the spring ball catches. The top manual simply pivots up, but the other manuals have to be pulled forward in their pivot slots before swinging them up. Reverse the process when lowering them.

If the top manual doesn't release relatively easily, check if the original hold-down screws are still installed (or were reinstalled) by looking under the front of the organ. I can't remember exactly where they are, but there will be an empty hole or a screw head with a washer at each end roughly in line with the middle of the top cheek blocks. If present, those 2 screws will have smaller heads and will be inboard of the 4 screws that anchor the keyboard frame. Do NOT remove the latter.

The contact rods and key fingers are gold plated and shouldn't need anything other than a gentle burnishing with something non-abrasive, like a strip of paper or the old dollar bill trick.

The biggest problem with the digitally keyed Conns was poor solder joints on the circuit boards, especially on the connectors, and poor crimps on the wires in the connectors. In either case, oxidation would creep in and cause intermittent connections. This has been discussed quite a bit in the Forum and you should be able to find the threads discussing the symptoms and solutions.

Other than these typically solvable issues, the 652 was a really great sounding organ.

The pipes were usually connected with a Conn adapter kit, which intercepted the complex (diapason/string/reed) channel speaker feed at the amplifier connector. It used a pad that kept the impedance above 4 ohms and allowed the balance to be adjusted against the internal 12"/6x9" set. Probably unobtainium now, but you could likely make something equivalent using a Parts Express pad.

--- Tom

[Reorganizing]

The key fingers on mine are all very black, but the busbars are mostly shiny gold, though with some black gunk accumulating in places - some old lubrication I'd guess, there are big warning labels under each manual saying not to use lube.

[don60]

Thomas, I was just in Blacksburg last weekend. I return from time to time and might be able to help you.

Meanwhile, you share the town with a large university having a good electrical engineering department. Perhaps a retired technician or faculty member could give you a little hands-on assistance. Not all of the professors at Tech are eggheads without practical skills.

[tleed]

Don: if you come to B'burg for football, it's a long time to August. If it's for family, I'm pretty sure they miss you & want you back right away.

I just posted a query for local help on the NextDoor app. I'll see what that turns up. Back in the Seventies, some engineering students tried to resurrect my brother's Schober organ. They weren't successful, but you probably couldn't blame them.

I suspect a connection mismatch between my 652 and Leslie 740 for some of the problems, and that if that's so, it's probably just a matter of re-configuring the pins. Some volume issues show up on the Leslie, but not through the onboard speakers. But I don't know how to troubleshoot those issues outside of trial-and-error, and I'm pretty sure that's a lousy method for an organ full of vulnerable parts.

Thomas

[don60]

I was forced to go to too many football games as a cadet during the Bill Dooley era and never had any interest in Tech football after that experience.

The Schober organ was 90% marketing and 10% design quality. I am not surprised that the students were thwarted or gave up. As other members have pointed out, you have much more to work with in your Conn.

Do you have the correct, official Conn service manual for this instrument? If not, work on obtaining one ASAP so you will be ready to help any helpers who show up.Conn manuals are particularly useful among organ service literature because they contain extensive discussions of operating theory for the circuitry.

[tleed]

Yes, I bought two documents online, and that's apparently what I got. It's really detailed, with explanatory paragraphs & pages of diagrams & schematics.

[Reorganizing]

Now the festivities are over, I've had a bit more time to look at it. I wired the pipe speakers to an external amplifier connected to one of my Allens to try them out - there's no pipe connector box on my 652, they were just twisted around the terminals of the internal speakers when I found it. I can't say that I'm impressed with the sound from them, but they're all working.
The top two manuals are both playing well, apart from the lack of the tibias, which are about half the stops on the great. The rhythm unit doesn't work, though there's random castanet sounds occasionally. The 20-year-old email indicates that this is not new.
The accomp manual is not so good. I think all the contacts are actually working, I need to trace the wiring to start looking at the signals at the multiplexer.

I've put a few pics of the organ in various states of opening up in my album.