Seems like I'm perpetually researching rather than actually trying anything with my organ (I blame my college homework🙄), but I had a thought about performing a simple organ split.
The main problem with splitting the keyboards from the tube channels is the mass of parallel wires that connects them. Is there a simple way to create, say, a serial connector that would be able to quickly connect and disconnect the keyboards and the tube channels?
The main problem with splitting the keyboards from the tube channels is the mass of parallel wires that connects them. Is there a simple way to create, say, a serial connector that would be able to quickly connect and disconnect the keyboards and the tube channels?
I would think you have to go digital, ie. muxed sensing of keyboard switchs, and muxed output of switch contacts (possibly open-collector or drain switchs, or possibly optomos), and a serial coms between, with at most a few ms transfer delay - great simple digital electronics project for academic courses.
MIDI. Serial digital control sends back note and if the keyboard is equipped, velocity of the key press. The keyboard end is comparatively easy. Decoding MIDI to drive the tubes would be more 'interesting' but certainly not impossible. Once you've converted the tube section to receive MIDI a whole host of possibilities appear.
G²
What type of tube organ are we talking about? If your organ is similar to the tube organs I have seen, then the keyboard switches carries complex analog signals and form integral parts of the tone controls, filters and delay lines.
If this is the case in your organ, then the switch connections cannot be replaced by simple serial on/off circuitry, digital, MIDI or otherwise. Any attempt at doing so would just ruin the whole thing. May as well build a completely new semiconductor based organ while reusing the old chassis.
- Frank.
If this is the case in your organ, then the switch connections cannot be replaced by simple serial on/off circuitry, digital, MIDI or otherwise. Any attempt at doing so would just ruin the whole thing. May as well build a completely new semiconductor based organ while reusing the old chassis.
- Frank.
He may be lucky Knarf and have a relatively simple older style organ, as my organ switches three note busses to ground with every key, and has three output busses and 12x5 note inputs, and so the two keyboards could be replaced quite acceptably with an optomos matrix sitting between the note generators and tone filters, plus another set for the pedals of simpler format. Each of the three key switchs are between 10M and 2.7M buffer resistors, so any optomos resistance would be fine.
In some ways this would be a reliability bonus for my unit.
Ciao, Tim
In some ways this would be a reliability bonus for my unit.
Ciao, Tim
OK, I'm not sure if I explained clearly, but thanks for the suggestions already. I'll rig up a YouTube video to show what I'm thinking.
Btw, it's a 1962 Conn 427M Caprice home spinet.
Btw, it's a 1962 Conn 427M Caprice home spinet.
OK, here's the video: YouTube - Organ split question
Excuse my non-technical language—I'm a newb, but learning quickly. So, what do you think?
Excuse my non-technical language—I'm a newb, but learning quickly. So, what do you think?
IIRC Conns used multiple contacts per key, 8' 4' 2' pitch, possibly 16' and 2 2/3' depending on the model. The oscillators are running continuously and you select the pitch(es) with the keys. Remoting it digitally will be hard. Analog will be even more difficult with the large number of wires and potential cross-talk. And when you're all done, it's still a Conn.
Just for laughs check out Hauptwerk and the examples played on YouTube to see what is possible with computers and MIDI. I predict you'll be impressed and maybe want to abandon the Conn project.
G²
OK,
I'm not trying to change the sound. I'm trying to physically split the organ into two sections to make it easier to transport. What I want is to make disassembling it and reassembling it as convenient (or painless) as possible.
The sound is going to stay the same, the organ is still going to do what it's supposed to. I just want to know if cutting those wires, creating connectors for them, and reattaching them will screw up the circuits at all.
I think you will find that you can easily cut and place connectors, or even extension leads, in the key/switch cableforms shown in your video. I reckon your keying set up is very close to my Selmer setup - the tone generators get keyed through to later tone shaping circuits, such that the signals being switched by the key contacts are just the oscillator outputs. Of course signal bleed will progressively increase with longer extensions, but I doubt you will notice any difference with short practical lengths.
You may want to consider using generic connectors and pre-made cables, such as used for computor serial or parallel connections. Enjoy the soldering!
Ciao, Tim
You may want to consider using generic connectors and pre-made cables, such as used for computor serial or parallel connections. Enjoy the soldering!
Ciao, Tim
Perfect! That's exactly what I wanted to hear. Time to get my hands dirty again. ^_^
There's no "simple way." How many wires are in each bundle? Presuming 25 or fewer, I'd use a DB-25 connector pair for each bundle. They're cheap and reliable. The problem of course is keeping the connections straight and the labor to dress and solder the wires to the connectors.
I was going to mention googling for chop organ, but looking around it's usually for Hammonds, and appears to be done is putting the amplifier in the top area with the keyboards and tone generators. This makes it a smaller package that will fit in a station wagon, but it's still hugely heavy. I didn't see anything offhand about disconnecting the keyboards from the tone generation circuitry.
Why exactly do you want to separate the keyboards? Is it to reduce the size of each thing to be moved, or the weight (or both)? What will the remainder weigh once you remove the keyboards? Those look like the common Prat-Reed electronic organ keyboards
Oh, and with googling chop organ I found where you apparently asked about this before:
Spinet organ chop—advice?
I'm not sure if it's a Prat-Reed—the keys seem awfully well-built and are entirely springless and hingeless.
I'm hoping to get it to a point where I can fit it in my car. Weight really isn't a problem, it's mostly size. I plan to make the whatever-it's-called box that controls the keying detach from the whole unit so it can be protected from jolting and jostling, preventing tube failures.
By simple, I meant something that didn't require completely rewiring the organ 😀. Soldering the wires to some DB25s should be no problem. There are, however, a few thicker power cables that drives the three or four oscillators for tremolo or sustain or something—these might require a bigger dedicated connector.
Yup, that was my earlier thread on the topic. I like organ forum, but DIYAudio has more general knowledge that I find more helpful.
Use multiple pins of a DB25 for heaters - all other power wiring will be down at the mA level.
If you ever come across a schematic/manual for your organ then I'd be keen to see it as a circuit design cross reference to http://dalmura.com.au/projects/Selmer Type B Concert Organ Manual Transcribed.pdf
Ciao, Tim
If you ever come across a schematic/manual for your organ then I'd be keen to see it as a circuit design cross reference to http://dalmura.com.au/projects/Selmer Type B Concert Organ Manual Transcribed.pdf
Ciao, Tim
Heaters?
I've found a service manual, but I have yet to purchase it. I'm going to do so right after I get done with some car repairs.
Your wires may include power cables for valve heaters - if so then those wires will carry the largest current of any cabling that may need to go through a plug/socket.
It won't screw it up but take the others suggestion of using as many pre-built cables as you can. It will save you miles of work and if one gets damaged it will be easy to replace.
BTW I had a Conn back in the '70s. It was difficult to keep in tune. The thing about Hauptwerk is it can be ANYTHING musical - including your Conn or a Hammond or .....
G²
Got it.
Actually, my Conn has stayed pretty much in tune for its nearly 50 years of existence. I had to retune it slightly recently, but it's stayed right on the money since then.
I've seen and heard Hauptwerk, and it sounds amazing, but I love the way my organ sounds already. Also, Hauptwerk can't be an overdriven guitar, so... 😉
Video of that to come...
Still working on the video (it's hard to show a good sample in three minutes, as my camera is limited to, so I might have to make multiple vids), but here's the first set of shots of the organ (inside and out) in 10, maybe 12 MP. Everything from the bus rods to the swell pedal mechanisms can be seen in high res.
Conn 427M Caprice shots 1 - a set on Flickr
Conn 427M Caprice shots 1 - a set on Flickr
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