Thomas Model 871 organ; what type/manufacturer of manuals?

[James56]

Hello folks, I have been offered a thomas 871 organ for free.
The kicker is that there are a few damaged key tops.
The organ plays fine.
I'm just wondering whom manufactured the manuals keyboard action so that I might research finding replacement keys.
Anyone know or own an 871 with some internal photos of the keyboard action?
Thanks

[andyg]

The answer is simple. Thomas made their own keys. Replacements are not available, unless you can find another similar or identical Thomas organ from that era (mid to late 1970s) that you can cannibalise.

Are they so badly broken that they can't be repaired, i.e parts physically missing?

[toodles]

You might check with Organ Service Corporation web site: http://www.organservice.com/thomas/thomas.htm for contact info.

[andyg]

They do list a few keys but there's no specific model numbers given, so it seems to be pot luck as to whether or not they'd have the ones needed. I know that that this question has arisen before and they were not able to help on that occasion, hence the statement about needing a donor organ.

But still worth asking! Don't expect a speedy response, though! While you're at it, you could also email W D Greenhill in the UK. wdgreenhill.com will get you there. Bill Greenhill used to be CEO of Thomas Europe, so I'm sure he had first options on the spares inventory when Thomas closed down and he set up his spares company. Again, a good company but not the speediest to reply.

There are, depending on where you are, plenty of old Thomas organs out there. All free or thereabouts.

[toodles]

In the mid 1970's Thomas changed their design from an "A" type keyboard to "B" type; the type of plastic changed--the newer one was harder, but more brittle, and the key contact design changed, too. Unfortunately the "B" type was prone to breakage because the fulcrum for the key lever was right in the middle of the thinnest part of the key--it created a weak point and keys often broke there.

But within the type, all keys are interchangeable for the note: A, B, C, D, E, F, G, sharp, and high C--9 different keys total.

With Organ Service corp a phone call will likely get a quicker response than email.

[jbird604]

The question might be whether or not that organ is worth the trouble. I've only seen two of that model in my career, and both were in abominable condition. The pedal keys have a pretty serious problem with a plastic contact pusher that gets brittle and deteriorates with time. The two organs that I saw both had a number of those pieces broken. Attempts to take good ones from the highest keys and transplant them to the lower keys generally failed, as the plastic was too brittle to survive being unmounted and remounted. I do suppose someone could re-engineer the pedal keys and devise a sturdier piece of hardware to do that job, given the time and skill.

Besides, the troublesome pedalboard, the two that I saw also had very serious contact issues on the keys and on the stop switches. So bad that it was nearly impossible to play them, even after I tried pretty hard to clean and adjust these switches. And the sound was little different from one of their $500 Christmas home organ specials they were selling at Sears back in the 70's when I worked there. No real attempt to imitate authentic pipe sounds, just various rather crude tone colors that might be "interesting" but quickly tiring to the ear.

My assessment was that the organ was simply not made to last. While Thomas had a certain appeal with their elaborate line of home organs, their build quality and technological sophistication was nowhere near the level of many other home organ companies. Not that they were the worst, but they just didn't seem to be built to last for decades, the way a premium brand would.

So, my sense is that Thomas thought they'd venture into the church organ market by simply up-sizing the same technology and construction methods they used for their fun organs. Very few churches took them up on the offer, and those that did probably regretted it before too many years, even if the price had been vastly lower than for an Allen, Rodgers, Baldwin, Conn, or other serious church brand.

Now, somebody else may have had an entirely different experience with one of these, and may have an entirely different opinion. Just my thoughts -- and with so many really good church model Allen and Rodgers organs available for not much money, why waste your time and money on something that has so many problems and weaknesses?

[toodles]

In general, I agree with JBird's comments on the Thomas quality, and I worked in their engineering department for a time.

Their mechanical quality was a definite weakness. After Thomas, I worked for Lowrey for a year, and was much more impressed with Lowrey's mechanical designs. But, of course, these also used many plastic parts and I don't know how they fared over time. The nice thing about Allen and Rodgers was that their designs often copied the general mechanical approach of pipe organ components which have a proven reliability track record.

[jbird604]

toodles -- No offense to the engineers behind those Thomas organs! You all were doing the best you could do with what you had to work with. I actually enjoyed demonstrating the little "Galaxy" models from Thomas that we sold at Sears. They weren't very sturdy, but they were a lot of fun.

Thomas organs were of course quite decent for what they were -- consumer grade home products that were fairly inexpensive, and that people enjoyed for at least a number of years before serious problems arose. I was really surprised the first time I ran into one of these church models. Before that I had no idea that Thomas ever got into that market.

It wasn't a really bad idea -- using a single divider generator and the simple keying systems borrowed from home organs. Gave people a real AGO compliant console at a very low price, I'm sure. They just didn't seem to hold up to the rigors of church use, and didn't last for decades the way people expect a good church organ to do.

Given that I have Allen MOS organs sitting in the shop that I can't even give away -- and you know that they sound far better than the Thomas ever did, and are built like a tank -- I try to discourage folks from sinking money into organs that just aren't going to give them much pleasure no matter how much fixing they do.

[toodles]

I inferred no offense at all--I worked as an electrical engineer for Thomas and our group was never fully happy with the mechanical engineering side of things.

But Thomas was definitely built for a price point, as are all manufactured products.

For the record, a large number of the B style keyboard keys were broken in the engineering lab--if the upper keyboard wasn't replaced very softly onto the lower, broken keys resulted. And it took a special tool to replace them because of the key spring arrangement.

By the way, I don't think Thomas ever built a 32 note AGO pedal board themselves--they outsourced a slightly modified design from Klann.

[andyg]

What Thomas church models are we talking about, John? Apart from the straight version of the 'Symphony' and spinet sized 'Studio 49', I can't think of any and there are none in Blue Book or Jan's "Mother List". The only models recorded with a 32 note pedalboard are the 'Impresario', 'OH-3' and the 'Palace III' models. All 'theatre' models. If you have some info on church/classical models, it's something we should add to the archives.

The 871 discussed here is presumably the final version of the Celebrity, the one with a Moog synthesizer built in.

[tucsondave]

Andy,

I have in my hand the service manual for the Thomas "Traditional" model 870. All the normal church organ voices and even an 8' Great to Pedal coupler.
It is dated January 1968. I was told back then that the AGO pedal clavier was supplied by Conn.
Speaker switching was interesting:
Leslie Swell Flutes.
Leslie Swell strings, reeds, diapason.
Leslie Great.
Leslie and main.

Old school tech. 12 oscillators, transistor dividers before the transistors were incorporated into the divider couplates.
"Duophonic" pedals.
I think this was still Warwick Electronics just before Whirlpool bought them.

The 871 was the Celebrity Royale. 25 note flat pedals, 1975

td

[Silken Path]

[jbird604]

Sorry about the model number confusion. Apparently the 870 is the AGO church version, and the 871 is something else entirely. Does that agree with the model history?

I assume that Thomas made relatively few of the church models. Or perhaps very few of them have survived. As pointed out, they outsourced the AGO pedalboard from elsewhere, and it was a basically good pedalboard. It was just the blasted contact pushers they tacked on to the ends of the pedal keys to actuate the contact springs. They were unworthy of the high quality AGO pedalboard!

Andy, as tuscondave mentions, it was very basic technology, little different from a Thomas Californian or other spinet model. Just 12 oscillators with dividers, direct keying and/or sustain keying on some voices, rudimentary voicing filters -- everything sounded more or less like a modified square wave. If there were any pistons, they were simple blind presets. It has been quite a few years since I saw one, and I'd have to dig out the service manual to verify the details.

[toodles]

On the Thomas organs that offered pistons, they actually were a capture action that physically moved the tabs. It was very much like a tripper action except that the power to move the tabs was provided by the piston motion, and so it had a relatively long throw.

There was a plastic track behind each tab of the affected voices, and a tripper engagement that was manually moved to the on or off position by opening the lid and physically positioning the tripper to the appropriate position. One tripper was present for each piston and each tab involved.

With the introduction of the Bicentennial Models: 1776, 2001, and Californian Theatre Deluxe 287, Thomas introduced a custom keyer IC driven by a Top Octave Synthesizer; this provided electronic keying for all manual voices, pitches from 16 thru 1 ft on the Solo, 8 thru 2 on the Accomp. This was a big improvement in the voicing capabilities of the organs. Pedals were generated (for the monophonic pedals) by the Features Module which did the auto chords, auto bass, fancy fingers, etc.

Voicing was definitely aimed at Theatre Organ sound. Filters for tibias were on an octave-by-octave basis, so they tended sound as good as Rodgers, Conn, Allen, or Gulbransen--only the non-flute voices had a single filter for the whole keyboard. But with these models and later, Thomas did work to get good voicing, and the filters were not the frugal affairs used in the early models. Of course, though, Thomas didn't really provide any significant diapason sounds. The strings were just staircased sawtooth waveforms with a little roll-off provided by the speaker system, but I thought they sounded right except for needing a little more high frequency response.

It would have been nice to hear what could have been done with the new technology with multiple dividers a la Baldwin and some complicated filtering--it certainly could have rivaled Baldwin's best efforts.

[andyg]

Thanks for the info on the 870. I'll add that to my own copy of the Mother List, which is in an 'unlocked' format.

A quick Google brought up this Organ Forum thread from years ago: http://www.organforum.com/forums/sho...istor-divider)

Never seen a church organ with traps and auto rhythm before! :D