Thomas Transistor Organ Model 810

[Klug407]

Hi I am working on my grandmas organ, I know very little about the electronics in these things but I think I know the main issue which is the pedal or amp because it sounds like a bowl of rice crispy and only makes sound around the middle position on it. Any help on how to clean it out safely or find a replacement would be greatly appreciated! this is the only major issue with it I'm not a keyboard player (yet) so I know only one key does not play but everything else even the motor for the tremolo still works! Thank you!

[myorgan]

Klug407,

Could you possibily post a video recording of what is happening? What you describe could be connection of the stops, the swell pedal (gas pedal);-), or any number of other things. It will help us help you.

Thanks in advance.

Michael

[Klug407]

Hi! Sorry its been a while been busy. I think my video will explain the sound I'm talking about. oh i forgot to record the loud POP it makes when you turn it off

[myorgan]

That's not a bowl of rice krispies-it's a load of fireworks! I'm not familiar with what is causing this, but we have techs who probably are. In a day or so, some of them can weigh in. Please contact me if they haven't in the next couple of days.

Michael

[Klug407]

Cool thank you very much!

[toodles]

It sounds like the expression pedal potentiometer is bad. Without the service manual you would just be guessing at the value of pot, and the difficult thing is this uses a dual pot and they are hard to come by these days. This might work, but it is just a guess. https://www.--------/itm/1-Thomas-Or...AAAOSwFFBdqgnQ

It's probably a big pain to remove the expression shoe and amplifier to get to the potentiometer. If you can find a local service person it might be a good idea Try MITA techs to find a service person: https://www.mitatechs.org/Service-Locator/

[Klug407]

Yeah the big issue is the 2 cables going into it that dont seem to have anyway to remove them (also not wanting to break anything) but yeah finding a service manual is probably going to be next to impossible.

[toodles]

The cables going into the expression pot are probably soldered.

[bnelson218]

That looks like an early Celebrity to me. First off, you definitely need a new potentiometer in the amp assembly. The amp and expression (volume) pedal are all one piece and the unit is pretty easily removeable. The pot is either a dual 10k or dual 100k (sorry, I don't recall which). You played a B key that didn't work. Are all the Bs out on the organ or just that one? If all the Bs are out then the B tone generator board is bad. If it's just that key, then you'll need to remove the back and spray some contact cleaner on the contact for that key. Also, a transistorized organ does not need to warm up. It should play immediately after being turned on. A service manual for that organ should be available from www.wdgreenhill.com. There are several connections made to the amp chassis which include 1 or 2 Molex connectors (square, white, multi-pin connectors) and 2 phono plugs. There are 4 nuts that hold the chassis in place--I believe they're either 5/16" or 7/16". I'd also see if Greenhill has a replacement pot. You want a good quality, sealed potentiometer. Where are you located? Maybe we can help you find a technician in your area.
I've owned and serviced lots of Thomas organs over the years, so if you have any questions feel free to PM me. Hope this helps!

[myorgan]

His profile says he's in Michigan.

Michael

[Klug407]

I'll check tomorrow if its all the B keys are bad. I looked shortly for a manual on that site it is a celebrity 810 (pretty sure). and yes your are correct on the amp/pedal its the 2 phono plugs that confuse me the most about removing it. I live in BFE sterling MI the nearest place I know of is in Lansing, Marshal Music co.

[bnelson218]

The organ is a 2-channel (stereo) system, with the tibias of the upper manual (swell) and the flutes of the lower (great) automatically sent to the Leslie channel (that's the spinning speaker inside and is controlled by the rocker switch next to the power switch). The string and brass voices of both the manuals, along with the pedals, are sent to the other channel which consists of a 12" and 15" speaker with a very simple passive crossover. The phono plugs are the inputs to the rotor and main channels.

[Klug407]

So I was being a big dumb idiot about the 2 phono cables they just pull out like any other audio cable of the time LOL :P . So now that i have the thing out this is what the back of the pot says (AB is stamped on the top so Allen Bradley) A-24-5183-3 REV B type J .I'm not having much luck finding what its numbers are but now that I dont have to find away to take a 400lb organ to Lansing it should be easy to get fixed.

Edit: All 3 of the first octave of B is dead so solo accomp and pedals, 3rd octave A# accomp, and 4th octave A solo is also. there is another model 810 in Ohio i thought about getting to strip for any parts also I could learn destructively about the organ with out damaging mine that sorta works(it already has multiple broken keys and similar maybe sound issues they didn't really know much about it). are these tone boards simple to unplug? haven't looked to closely yet at mine. Also what do you recommend to clean contacts with? I did buy some Deoxit D5 I was going to use but I want to be sure...I got it cause it says its safe on plastics and stuff in older things and cause it has high ratings LOL

[John Vanderlee]

one thing you could try is to spray the DeOxit all over the potentiometer. Even though they may be “sealed”. Some times molecular amounts will find their way inside and help to clear up the insides. Do this while vigorously working the pot.No guarantees implied;-)
I have gone as far as taking a very tiny drill bit to this and creating a small hole in the case for cleaner access. but you'd have to be very careful with a steady hand. You pop in too far and destroy the insides.
Only a last resort!
John

[Klug407]

I did see each one has a small hole in the bottom and one has some weird looking grey gunk covering like half the hole. If DeOxit is good stuff to use i'll try that and see what happens. I'm glad it does have the holes cause there is no way I would trust myself to drill a hole.

Also I have found a service manual it should be here around the end of the month!

[tucsondave]

Do not spray contact cleaner on this organ. It used conductive vinyl buss bars which can be destroyed by contact cleaners.
For the dead notes the first thing to try is remove the 1/4 hex head screw that holds each of the twelve tone generator boards in place. Unplug each generator board then plug them back in.
They can be accessed from the top of the organ as you will see when your manual arrives.
For the expression pedal you can try exercising it back and forth to see if it improves. It used carbon wipers which when worn out allowed the metal holder to contact the resistance area. If that's the case then cleaning or exercising it will not work.
Also unplug the RCA cables and check for the noise.
td

[Klug407]

HA HA WELL too late but I did make sure that the cleaner was safe for plastics sense vinyl is a plastic it should be okay. But the organ has never sounded better! I was going to post another video today and ask about the tone generators and ask what causes them to go bad? I remember reading some where that the black caps on them dry out or explode? or something.

[Klug407]

I will work on a note by note video but what is a stop? LOL I know I've briefly said in my videos but I know nothing about playing a keyboard instrument. I did play the trombone in high-school so I can read bass cleft easily, working on treble cleft lol so yeah lots of dumb questions incoming.
another thing about making this video, do you need a certain amount of "voices" selected for a set of keys to work on this organ? cause I've done some playing around with it and noticed something like that. can you be super specific with this one? lol

and yeah one week of work and its so much better so thank you each and everyone of you!

[John Vanderlee]

Did you actually spray the pots? Was that part of the fix?
John

[Klug407]

Yeah John I sprayed a little of that deoxit d5 in them and it actually could play music now! and not sound like 4th july fireworks! lol :D