Allen TC-3. Please help me understand it's guts. And the diapason stops don't work.

[storckm]

Hello:
I've been given an Allen TC-3, and am trying to figure out how it works, as well as whether I might be able to fix the diapason stops.
Some specific questions:

What does the "Horn Speakers" stop do?

All of the Diapason based stops do not work: Diapason, Double Diapason, Octave, Super Octave. There are two large and one small racks of what I surmise are tone generators, marked diapason, diapason celeste (which also doesn't seem to work) and reeds and flutes. Is there some likely reason why all and only those stops don't work? I'm not sure how to begin diagnosis.

There is a switch on the diapason rack, and I have no idea what it does. (I did try in both positions.)


There are two different arrays that could be power supplies. Could you please explain why?


And one of the bulbs that are activated by the pistons is burnt out. Where do I find replacement bulbs, or can I make one using the base of the old bulb and an LED?

There are also a few loose wires. Is this a problem? Is there some way to figure out where they go?


Thanks for your help.

[Jan Girardot]

I urge you to invest in one of my books, 'Allen Analog Organs' . Send me a PM (Private Message) and I will send you a PDF describing the book in detail.

. . . Jan
the OrganGrinder

[Pipeorganbuilder]

The light bulb is a #330 lamp and can be ordered from Jameco, Newark and Allied electronics. These are used as a form of relay to switch things on and off. Best to buy a supply of them and replace all lamps. The expression pedals use lamps also. Please check these. I always replace all lamps when I work on these organs. They are too cheap to have one burn out after I leave and have to return later. Make sure that the power is off when you change these lamps so that you do not short out the lamp supply.

[toodles]

For the celeste oscillators to sound, there should be a tab marked "celeste strings"--that has to be on for the oscillator outputs to get through to the speakers.

I haven't run across a "horn speakers" stop on an Allen, but suspect it routes the sound through a set of horn speakers. Might be useful for outdoor horns (typically used with the carillon/chimes stop), or perhaps for some special purpose where the organ was originally installed.

I wouldn't know if the loose wires are important--you'd have to track down what they are connected to.

I am not familiar with Jan's book, but detailed info on Allen organs (even the analog ones) is very scares, so I suspect it would be a wise investment.

[OrgansR4Me]

I own Jan's book and highly recommend it. Some of my older repair books from the late 50's and early 60's are also useful for early Allen. You have two separate amplifiers which is very common in Allen organs. The fact that diapason is completely out means that amp is also probably out. Dropping in another parted amp is usually the easiest route to repair. You'll find some available on Ebay but be cautious about the prices. Some cost more than a used organ. You'll want to be dedicated if you decide to restore your organ. It will take home work each step of the way.

[storckm]

Are you sure that they're #330? The #330 seem to have a flange in the base. The ones from the organ have a pair of little pins that twist in to place. Also, there seem to be about 3 different bulb shapes with the same base.

[toodles]

Post a picture of the bulb and we can try to identify it.

[storckm]

Here's a picture.

The bulb on the left is from the general, the second is for the crescendo pedal, the third I found clipped to the inside of the organ below the crescendo pedal, and the fourth and rightmost is the power on light, apparently the same as the first. I think, however, that the second may also be interchangeable with the first and fourth, as the other two crescendo lights are the same as those two. The third is bigger and won't fit into the space for the other lights. The fourth is marked H313, the third H57X, and the markings on the first and second weren't clear enough to read, except that there's an H on the second. The other two, from the crescendo indicators, were marked GE 1889 and CM1815. I'm thinking this is what I want. Yes? And what about the odd one?

[Pipeorganbuilder]

The #330 is used on the pull out generator boards using the small round alum. relays. The #57 is used on the expression pedals and the 'X' indicates it has a black dot on the very top to prevent blinding the photo cell.

[toodles]

I believe the black dot was painted on by Allen. If I remember right, it's a 14.4 V bulb, but run on lower voltage so they tend to last forever.

The type of bulb for these is "minature bayonet".

[Pipeorganbuilder]

You are correct. Allen used black paint to put the spot on the end of the bulb. The bulb has a wire wound resistor in series with it to limit the light output which in turns extends the life. Thanks for pointing this out. I have got so use to painting the dot that I forgot to mention this.

[storckm]

Thanks for all the help so far.

We spent some time visiting my wife's family, and while we were there, my mother in law cleaned out her basement. I brought home an old stereo receiver, and had the idea that I could plug the organ's output into the phono input, since it is my understanding that the phono input includes a pre-amp to amplify the low line level of a record player's output. However, when I had plugged the organ's output into the phono input, not only was there a lot of noise and buzzing, but I was also receiving a radio station. This happened even with the organ turned off--the buzzing was a bit worse then--but not when the wire was not attached to the organ.

Do any of you have any idea why this is happening?

I have managed to get usable volume, although not what you'd expect from an organ, by plugging the organ's output into a computer speaker, and then wiring the output for one of the satellite speakers into the receiver. There's very low noise, and not even a trace of the radio station. This isn't a very elegant solution, and I'd like to figure out what is actually going on.

[Admin]

The phono input is not a suitable input because it provides RIAA equalization and the frequency response is not flat because of this. The noise, buzz, hum, and radio station are indicative of poor grounding and shielding. Try plugging into a line level input

[storckm]

This would seem to imply that the organ is not properly grounded and shielded, since the radio station and humming only occur when the amp is attached to the organ. But why does this happen only when the organ is attached to the phono input? Would adding a grounded plug to the organ help?

[NoTalent]

You don't want to use the Phono Input as that is an extremely low-level input; i.e. lots of amplification. That's the reason for all the noise and radio station stuff. You may even have blown the Phono input by putting such a high-level signal into it, but you probably don't care.

Anyway, you want to use a "Line Input". On a receiver, that would be something like "Tuner", "Tape In", "Tape Monitor" or "AUX".

However, I don't know if the outputs from that old TC-3 are compatible with standard Line Input levels.