Allen TC-4 Project

[Silken Path]

Well, several of the pedals don't work - mostly on the low end. The phenolic board that the pins are mounted on is broken in two on the wire end. I looked at it and decided that the wires were still connected, so tried it. The first four or five keys are not working. I think it's likely that it's either that plug OR the brushes, but I'm leaning toward the plug, since the pedalboard has been wrapped up and protected since before loading it.

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Appears to be the plug. I have one on the old organ, but it has not been well treated. No wire markings on this - just a bundle of brown wires. I guess I'll be learning about the pedal keying system next. :)

[toodles]

The chiff is only for the flutes. The effect is extremely subtle to my ears, and, of course, it only occurs at the onset of a note. It may be that the circuit to turn it on and off is needing repair.

[Silken Path]

Thanks, Toodles. I'll experiment a little more with it.

My next priority is going to be getting the pedals working. This stuff is tiny and unmarked, but I have the one from the '59 and the first part of it is all right.

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Here's the crack in the first octave pedal-board connector. It looks pretty innocent, but when I removed the wire lacing, there were several loose or broken wires. Only the ones on the first part, beyond the crack, and the larger power wire (red) on the other end looked great. Beside it is the donor plug from the '59. It took a bit of straightening/prying, but it fits fine.

Twelve pins on the first one each represent one pedal. Pushing a pedal moves it down so a contact plate pushes against whiskers and puts 14 VDC on the line through one of these pins back into the organ.

Rather than go dig around in the organ to try to follow the wires back to their source, I'm going to splice in the donor plug and identify which wire is which by listening as I activate a tone and find the pedal. This won't be the worst thing in the word, but this is what happens when you get too gung ho. :)

[Silken Path]

Repairing the pedal board wiring

Here's the first bit of the repair - isolating the 13 wires that go to the first plug and marking them.

Next I'll do the same for the pedals and mark the wires from that end. Then I should be able to splice each wire together, cover in shrink wrap, redo the lacing using the existing sticky waxed string, and tape it back up.

And does anybody know what this tape that has lasted 50 years is called?

It's sticky on the inside and dry on the outside. It's fabric, but it leaves sticky residue on the wires inside and has remained flexible after all this time. I don't think it's a friction, rubber, or electrical tape. What's a modern equivalent?

[myorgan]

And does anybody know what this tape that has lasted 50 years is called?

It's sticky on the inside and dry on the outside. It's fabric, but it leaves sticky residue on the wires inside and has remained flexible after all this time. I don't think it's a friction, rubber, or electrical tape. What's a modern equivalent?

It's for questions like this I begin missing Jan Giradot (RIP)! What a great wealth of knowledge he shared with all of us!

Unfortunately, I don't know the answer, but I certainly look forward to seeing the answer. What you're describing sounds a bit like cloth tape or micropore used in the medical field--except that it's white.

Michael

[Silken Path]

TC-4 Pedalboard wiring repair

Well, here's progress for today. I got the donor plug from the '59 tested and all the prongs had good continuity. Identified the twelve wires from the organ by selecting Flutes 8 on the pedal and comparing it to Flutes 8 on the lower manual. Identified the same on the pedalboard by clipping on to the red wire and looking for a wire that answered when a pedal was pushed (from underneath, as the pedalboard was standing up). Then just spliced them together, checking everything several times before committing.

Well, that took me all afternoon and part of the evening. I think one sort of has to do a lot of this work one's self in order to afford one of these old organs. Now I think I'll go play it for a while.

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Oh, and one of the amps is making a roaring noise. I need to confirm it by removing the input (it may be the organ). :) Since I have the T-50 schematics and alignment service bulletin, I'll take it or send it to Atlanta if it needs repair.

[Silken Path]

Sir Toodles, either the Chiff has started working... or I just started hearing it. I would describe it as a little percussion. It's most noticeable on songs like "Sweet Hour of Prayer" where it adds a crisper feeling. As you said, it's subtle.

The organ is improving as a play it. When I get it into a more permanent location, I'll need to adjust the sound levels. Either the flutes aren't loud enough or the diapason is too loud. Diapason + Celeste is right beautiful.

The Flute 8 is dropping out, or at least dropping in volume, sometimes on both manuals' 8' Flute. I'm going to need to go look for that, and it just may be why the flutes aren't loud compared to the diapasons and reeds.

The bass speakers are having no problem handling the lowest notes, and I'm not hearing any flapping in them. 16' is the lowest stop I can get without the pedals.

Interestingly the section on voicing the organs says to make adjustments at full pedal. Some organists, it says, tend to forget and leave it there, so it should be adjusted not to blast out the people in the first rows.

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I can make a lot of the adjustment between the reeds, diapasons, and flutes using the gain controls on the amps. (The little Rodgers spoiled me by putting the level controls for the top and bottom manuals and the pedals right there at hand.) To my surprise, exercising the gain control pot on the noisy amp reduced the noise a lot.

"Sustain" in the early 60s is apparently not what the 70's notion of it or the 90's notion of it is. It only lasts a second or so. In fact, it's like a little bit or reverb, sort of, and I think I'm going to be inclined to leave it on. (I leave "Glide" turned on in the Rodgers, too.)

The "becomes" like "Diapason becomes Viola" seem very useful because they affect both manuals. "Flute becomes open" is not a lovely sound.

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About the tape for the wire bundles - how would say a cotton friction tape (both sides sticky) do with a thin rubber tape over it? The notion is it should keep the wires from having relative motion but stay flexible. These have lasted over 50 years.

2nd question - While I have the tambour out, it would be good time to maintain the the magnet switches. The only problem is that one of the switches (lower manual diapason) works on/off but doesn't clear. Would contact cleaner hurt anything? (Like maybe tend to wash out lubricant or something? The ASM is silent on this point.)

[Silken Path]

I decided to go with 3M 3407 NA, 2 pack for less than $10. It's a friction tape that is reportedly sticky on only one side. We'll find out. :)

[Larrytow]

Well, 3M makes the best tape of all kinds in my opinion. But if I were doing that job, I would use the Super 33+ electrical tape. That tape is always in my shop, so it is my go-to for anything electrical. I suppose if you are trying to match the original tape, then the friction tape might be the way to go. You will hate that black sticky residue from it though, should you ever need to take it off again.

Even on a restoration job like you are doing, there are times when modern supplies are better for the task at hand.

The pedal wiring does not get much wear usually, because it just lays there on the floor when the organ is installed.

[Silken Path]

Well, my reasoning is that the fabric tape will be flexible and resist abrasion. I imagine something more current than TAR is being used. I also hope it will stick to the old fabric tape, which may have actually been a friction tape when it was made. :)

What galls me a little is that I did run electrical tape around the three sockets on the pedals, which are neat engineering in themselves. (They have a roller hinge on end, so to install them, a few screws would be run into the wood, and the row would be rotated down and secured with a pop-rivet.) I thought the plug boards on the organ would be safe looped over the loop under the setterboard, so finding this crack, which I strongly suspect was caused by yanking the plugs out during un-installation, was an unpleasant surprise.

I had to decide how to do the splices. When I worked on airplanes, we tended to used good quality butt splices because vibration could work harden and break solder joints. On the organ, I ended up doing so-called "NASA splices" - basically make an X and wrap the top parts in opposite directions. Then I just soldered them and used shrink wrap.

I'm not averse to improvements, where the benefit is immediate or obvious or remedial. For example, I'd replace the fluorescent with LED strip lighting (and get the pedal lights, too) if the deck light goes out. Any electronics that need repair now may make it last for the next 50 years. Who knows?

So far, I'm pretty delighted at the way things are going with the organ. It has capacitors stacked on capacitors in long rows, and it's complicated. As I mentioned above, the first time I tried pushing a piston in, the power light dimmed, the blower wind light went out, and the organ let out a AC-sounding MOAN, like an engine straining its guts out. Then it woke up.

Lucky I didn't have any stops selected... Now it still dims the lights, but the presets can throw a lot of magnets, too. I'm going to watch a voltmeter to see just how much the 14V does go down.

It's amazing it's working at all.

[Larrytow]

Yes it is amazing that it is working, but not a total surprise. Allens are well built organs, and yours is not the only TC-4 that is still playing today.

Ya, I'm sure the pedal wiring plug was wrecked by someone when it was removed. It is real common for non organ people to mess up pedal wiring or contacts, because they just don't know any better. As I said, otherwise the wiring just lays on the floor and is hardly ever touched.

Never heard those sorts of splices called NASA splices. Been doing them exactly that way for years on trucks. I just called them Forever splices.

Sometimes one of those capacitors on the oscillators can change value a good bit. If that happens, a note will go way out of tune, and you won't be able to tune that particular oscillator back to correct pitch without changing out the capacitor. That is not a real common issue though. In all the years I had mine I only had to do two of them. The books should have all the details on that if should you encounter that problem.

To move all the tabs at once does take a lot of current, so that is the dimming of the lights you are seeing. Mine did the same thing - perhaps not as much as yours is doing, but it was very noticeable. It never affected the sound though when changing combinations while holding a chord and pedal. It would be pretty unusual to have to need to have all the tabs move at the same time. In normal playing probably only half of them would ever need to move when changing combinations.

I guess you figured out how the combinations work by now. But if not, a quick explanation is this : It is technically called a Collective General piston arrangement. That means that whatever you have set on the 4 general pistons is also set on the divisional pistons. So when you push one of the general pistons, all the divisions change to the settings in the drawers. But you can change only one division at a time by using the divisional pistons for each one. You just cant have separate settings for each division, independent of what is set on the generals. That is not the handiest system of pistons, but it does beat blind ones, or none at all. Once you get used to it's limitations, it can be quite useful.

[Silken Path]

I haven't even thought about it. I saw there were four rows of switches - two in each drawer - and four sets of pistons. Now I really don't understand. :) OK - let me go look at the organ.

All right. I'm going to have to study this a bit. What I see so far, and this may be wrong, is say set Flutes 8, 4, Naz on the swell to piston 1. Set the 32, diapason on the pedals to piston 1.

Press 1 on the left and get 32, diapason on pedals + Flutes 8, 4, Naz on the swell.

Press 1 on the right and get only Flutes 8, 4, Naz

So one would only use the pedal pistons for sweeping changes across the row, but one can use the swell pistons to change the registration without altering the pedal stops.

But ah, you can't go back and select another pedal piston without messing up any new registrations selected on the right... And changing a reg on the swell side doesn't change the pedals... and there's another row beneath that...

Well, I'm getting bleary eyed and yawny. I shall consider this further on the morrow. Thank you for bringing this topic up.

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And the unconnected comment of the day is that both my organs have notches in the top where some organists slid the tambour cover up, multiple times, with the key still in the lock. I notice that on the newer organs, Allen moved the lock to the outside pedestal.

PS - I know where one TC-4 is that is NOT playing. It's my '59 parts cow.

[Larrytow]

Lamar, sorry to bend your mind so late at night ! LOL

When you next play with the pistons, they are arranged like this : The 4 on the left side under the Swell manual are the Generals - they change the stops on the entire organ all together. The 4 on the right side under the Swell manual are the Swell Divisionals - they change only the Swell stops. The 4 on the left side under the Great manual are the Great Divisionals - they change only the Great stops. The 4 on the right side under the Great manual are the Pedal Divisionals - they change only the Pedal stops.

So the most sensible way to set the pistons is to set up the Generals with entire organ registrations. Usually people set them up from soft to loud. IE : Gen 1 is a soft registration for quiter pieces, and then increasing in stops till Gen 4 is almost full organ. Perhaps not all the reeds and the 32' though, as you can always add them manually.

Then you can use the Generals for big changes, and the Divisionals to change their respective divisions as desired. Always keeping in mind how you have the Generals set : Whatever is on say Gen 4, is also on Pedal 4, Swell 4, and Great 4. Just that you need not change everything to use those settings with the Divisionals.

I am not certain anymore if the Divisionals change any of the Trem or the GEN tabs or not. I'm pretty much recalling that that the Generals do, but am not Sure, Sure.

I also cant recall if perhaps the Great Divisionals might also change the Pedal stops. On some older pipe organs the system does that. I don't think the TC-4 does though.

And then the Cancel piston way on the right side under the Great manual cancels anything that is on. Very useful in church to clear everything before changing music, just in case a book falls on the keys !

[Silken Path]

No problem, Larry. I'm going to play with it until I understand the vague outlines of its use. Thanks for all the information. That's much better than going in there blind.

Hey, I heard back from Allen. My organ is a '67. (Getting nearer the digital revolution.)

There are no more reprints/copies of the owner's manuals/user's guides for the old analogs, as per Sandra G. at Allen, so eBay is now the official source.

And she gave me the contact information for Allen in Atlanta. I bet they're just dying to hear from me.

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Maybe they are. They just emailed me. They're about 55 miles away. Jeff A. is the contact there.

[Larrytow]

Yours is much "newer" than mine was - pretty sure mine was a 59 or 60. The Allen owners manuals are generally pretty minimal ( OK, lousy ! ) affairs. You already know way more about your organ than you will learn from the manual.

I'll have to look again though my Allen stuff, because I just may have a copy of the OM mixed in with other organ series' paperwork.

I suppose that "someone" ought to take the time to digitize some of those old analog organ manuals for posterity, since Allen does not have it anymore. I actually thought that Allen themselves might have / should have done that already. But obviously not.