Early WurliTzer Electronic Organs

[bluetantra]

History and Overview of WurliTzer Electrostatic Reed Organs

In the years following World War II, the Rudolph WurliTzer Company resumed manufacturing organs in their North Tonawanda, New York plant, where they had been manufacturing organs for several decades prior to the war's interruption. WurliTzer had discontinued its pipe organ production a number of years prior to devote full research, engineering and production facilities to the new electronic organs.

[WIKI]WurliTzer [/WIKI]purchased the Everett Piano Company of South Haven, Michigan to gain gain the technology of and rights to the Everett Orgatron. WurliTzer continued to build the organs under their own name in the years following the war. Small-, medium-, and large-sized two-manual organs, as well as single keyboard instruments were available in Contemporary, Early American, or in traditional 18th Century console designs, finished in mahogany and walnut. Special finishes were provided if desired.

All of these early WurliTzer electronic organs are similar in their tone production method, differing primarily in size. They use wind-blown reeds, vibrating close to electrostatic pick-ups which convert the mechanical vibrations of the reeds to electrical impulses. The impulses are filtered, amplified, and reproduced through loudspeakers. The blower, reed chests, stop mechanism, and coupler action are all contained inside the console. Smaller models contained the amplifier and loudspeaker inside the console.

Tone Generation

Free reeds are used in these organs to produce the fundamental and harmonic frequencies. These reeds establish their frequencies by means of narrow tongues of thin and elastic metal, each of which is set in an individual metal frame, provided with a rectangular orifice, above which the tongues, being slightly smaller, are fixed at one end so that when air is passed through, the unattached end is free to vibrate in and out of the frame without touching any point, effectively making it an air-gap capacitor. All the reeds are tuned in accordance with the equally tempered scale. The rich harmonics created by the reed are natural ones, bound up with their corresponding fundamentals.

The reed, like a string or air column, does not usually vibrate at only one frequency, for besides its fundamental, it produces overtones or harmonics. These are higher in rate of vibration than the fundamental. The number of each harmonics or partials depends to some degree upon the manner in which the reeds were set into vibration, their materials and the distribution of the metal, scaling, voicing treatment, the air chamber in which the reed individually vibrates, and electronic control of all the vibratory elements.

Each reed has associated with it a 'tone selector' which is adjusted over a predetermined part of the reed tongue, according to the extent of harmonic elimination desired, to produce tones of various characteristics. 'Tone Selectors' are connected to the input of an audio frequency amplifier in such a manner as to generate electrical impulses in response to the mechanical vibrations. The reeds of the various tonalities are connected to polarizing (DC) voltages from the power supply. Between the Tone Selectors and the reeds exists an electrostatic charge. The movement of the reed tongue varies this charge, setting up an alternating current that is transmitted to the grids of the vacuum tubes in the console pre-amplifier. These electrostatic impulses created by the various tone-producing reeds are then conveyed to the main amplifier and on to the loud-speaker cabinets.

The underchest, magnet, and pallet board assembly is the heart of the organ, The underchest is in effect a reservoir which stores currents of air from the blower as a large volume, supplying it at constant pressure as needed. The pallets are a part of the chest magnets. They cover openings which lead into individual reed cells. When the chest magnets are energized through a key or pedal contact and the stop action switches , each pallet uncovers a hole which allows wind to vibrate the reed. Pressure should be from 2-1/2 to 3 inches.

Since the reeds at the low end of the pedal chest are necessarily very large, they have an inertia which keeps them vibrating a short time after the pedal key is released. Later organs used pedal-shorting switches which removed the polarizing reed voltage from the lowest 12 notes after the note was released. Subsequent models incorporated this feature on the lowest 24 notes.


Models 5 & 6


Models 10, 14, & 15

Single manual, 12(?) pedals. Model 14 includes internal amplifier and loudspeaker; Model 15 requires installation of Model 150 Tone Cabinet.
Stop List: Bass- Open Diapason 8', Dulciana 8', Violina 4', Dulcet 4', Vibrato, Tremulant, Full Bass. Treble- Open Diapason 8', Dulciana 8', Violina 4', Dulcet 4', Flute 2', Full Organ, Full Treble. Pedal- Open Diapason 8', Dulciana 8', Violina 4', Dulcet 4'
Control: On/Off Power Switch (with indicator light)
Pedal Movement: alanced Swell Expression Pedal


Models (Series) 20 & 21

First produced in 1946, the Series 20 Organ is a two-manual instrument, 61 notes each, with a concave radiating 32-note pedal clavier. (The service manual for this instrument uses the word "Series" rather than "Model") It includes Crescendo and Expression pedals, combination pistons, and provisions for echo organ, chimes and tower amplification. All playing dimensions and console arrangements of the Model 20 conform to the recommendations of the American Guild of Organists. Dimensions: Console with Pedal Clavier - 63-1/2 inches wide x 47 inches deep x 48-1/4 inches high. Console without Pedal Clavier - 63-1/2 inches wide x 31-1/2 inches deep x 48-1/2 inches high. Weight approximately 800 lbs. The standard cable shipped with the instrument, connecting the tone cabinet to the console, is 35 feet long.


The Model 21 organ was brought out a short time later and is similar to the Model 20 except that it includes a Great-to-Pedal coupler which provides all the stops on the great manual in the pedal section, except for the 16' pitches and the Celeste 8'.

Stop List: GREAT- Bourdon 16', Viola 16', Open Diapason 8', Flute 8', Flauto Dolce 8', Viola 8', Dulciana 8', Celeste 8', Octave 4', Flute 4', Violina 4', Twelfth 2-2/3', Fifteenth 2', String Mixture 2', Chimes (provision). SWELL- Bourdon 16', Stopped Flute 8', Flauto Dolce 8', Viola 8', Dulciana 8', Voix Celest 8', Stopped Flute 4', Flute Twelfth 2-2/3', Flautina 2', Oboe 8', Tremulant. PEDAL- Major Bass 16', Dolce Gedeckt 16', Octave Bass 8', Diapason 8', Violoncello 8', Flute 4'(Model 20 only).
Controls: Echo to Main, Echo On-Main Off, Great to Pedal Coupler (Model 21 only), On/Off Blower Motor, On/Off Amplifiers/Power Supply
Pedal Movements: Balanced Swell Expression Pedal, Balanced Crescendo Pedal with Indicator Light
Combination Pistons: Piston Nos. 1, 2, 3, 4, 5 (located under Great manual) actuating stops in Great, Swell, and Pedal divisions.

Tone Cabinets supplied with the Series 20 & 21 organs included either the Model 42 standard Tone Cabinet, intended for installation where the Tone Cabinet is concealed from view, or the Model 40 DeLuxe Tone Cabinet meant for visible installation. The Model 40 DeLuxe Tone Cabinet was designed and finished to match the console. Both models contain four speakers and two amplifiers. Dimensions: 38-1/4 inch wide x 21-3/8 inch deep x 35-5/8 inch high. Weight is approximately 250 pounds.

Also available were the Models 60 and 62 Echo Tone Cabinet, designed for echo and antiphonal effects. Model 60 carried over the styling of the Model 40 DeLuxe Tone Cabinet and intended for open installation. Model 62 was intended for concealed installations. Dimensions: 24-5/8 inches wide x 19-3/8 inches deep x 30-3/4 inches high. Weight approximately 110 pounds.

Model 25, 25G

Models 25 and 25G organs were introduced a few years after the Model 21 and are similar to the Models 20 and 21 except for their Contemporary case design. Their specifications, though, are somewhat different. Solo voices are provided on the five combination pistons with appropriate accompaniment on the other manual and pedals. A Great-to-Pedal coupler incorporated in the Model 25G permits the addition of 8', 4', 2-2/3', 2' and 1-3/5' and a string mixture in the pedal division. The model 40 Tone Cabinet and bench were standard with these models.


Models 30, 31, 45, & 46

Model 50

Sources: WurliTzer Series 20/21 Service Manual, "Electronic Organs" by Robert L. Eby, c. 1953.

(to be continued)

[paulj0557]

I just noticed this page today. I am very thrilled with my Wurlitzer electrostatic reed organs- models 4410 free reed, and 31 keyed reed. I play the 4410 daily, hooked to a Hammond HR40 with a Wurlitzer Spectratone and Leslie/Jensen V21 rotary horn in place of the HR40's 2-12" speaker ( Treble Channel), and a Wurlitzer 310 'vibrato cabinet'. For the low end the HR40's 9-10'' speakers on it's BASS CHANNEL are adequate. However, I happen to have an old Altec A7 sitting there in the basement. I 'temporarily' removed the horn from the top of this cabinet so the Spectratone and Leslie horn (have Leslie mounted in an old drawer) could sit on top and be at the same height as the top of the HR40. Being sure to check my impedance I have successfully been able to incorporate the The Altec A7's low 15", crossover ( 800N) and in place of the Altec Horn have attached both the Spectratone and the Leslie horn.
Ultimately my Leslie horn will have to make it's way back to it's 31H cabinet, but I have gained much practical knowledge as to what sounds best on a Wurlitzer electrostatic free reed organ. Straight away, the 1946 Wurlitzer 310 Vibrato Cabinet is a jewel. It's upper rotor is subtle, but effective. Although it was designed for the earlier keyed reed models, AKA the 31 it came with when I bought the pair 2 years ago now. Nonetheless it sounds just great on the 4410 free reed organ. Adding the 4410's own vibrato settings to the cabinet achieves interesting combinations. I rarely put the ' vib level' on the 4410 past the low setting and almost never use the fast rate. Mainly because between the Spectratone's spinning 4" speakers and the 310's upper vane rotor I'm getting plenty of frequency (pitch) modulation. I might note that I have hooked a larger 'in organ' wooden drum rotor that I borrowed from my Thomas Palace III ( it was sitting there in the basement next to the Thomas, awaiting restoration...so why not?). I believe this is a 10" Jensen in the Thomas Leslie. At any rate, it sounded excellent, but the superiority of the Spectratone on a Wurlitzer is staggering. Maybe this is a matter of taste, but after careful swapping back and forth between both an 8" in-organ Leslie wooden vertical drum and a 10" vert. drum, and Spectratone 2-4" it was clear that the Spectratone promoted the Wurlitzer sound the best. Now having the Leslie V-21 high rotor on at the same time as the Spectratone has me very spoiled! It does sound truly amazing, but in swapping between Spectratone OR Leslie horn, again the Spectratone just sounds right. So how would an actual 12" or 15" horizontal Leslie drum sound? Probably great. In fact, the less intense 310's upper steel vane rotor sounds very adequate with it being the ONLY external cabinet. In fact, the 4410 is perhaps one of my few organs that sounds great with only it's stock speaker playing and that's it.
What would I like to change, or modify on my 4410?
- have shorter sustain lengths, as a choice
- remove sustain from pedals as a choice
- make pedal levels more even, the G and upward is weaker than the F# and lower.
- Tonally I wouldn't change a thing, but I would like a brass reed family represented, if even just one tab on the upper manual. Perhaps I will investigate adding this voice on my own. I don't have a schematic of the 4410 or the 31 and am somewhat confused about the voicing beyond the pick-ups. Is there filtering? I want to ask some questions to someone who knows these designs well. I am well versed in most analog electronics and have even read the North Suburban Hammond Organ Society's, and Eric Larson's extensive articles on the ES reed organs.

I am torn about what to do with my Wurlitzer series 31 Orgatron ( never got a bench). I will keep the 310 Vibrato cabinet for my 4410. I don't feel like I am breaking up a set since the 310 cabinet has a different appearance than the 31 organ. they were sold together though and the resemblance in the model numbers is an obvious natural pairing. The 31 organ has no internal speaker ( the 30 had the speaker & vibrato wand) so it did need a cab, plus it has a vibrato tab to control the upper rotor on the 310 cabinet.
If anyone reading this is interested in the 31 organ, I have put it out there already, but don't want to make my final decision until I hear an actual series 30 or 31 on tape,video, record, or online. Ironically someone who has one has made a request to have mine if I am offering it ( of course I offered it already as a maybe... and it was their response which became a request)...but the condition of my considering them as a possible new home is that I be able to hear a complete demo of a 30 or 31 that they own already. Just for my sake, I WANT TO HEAR ONE! lol Okay, so that came and went with no response. As you can tell i am not in any great hurry to part with it, but it is in a storage just sitting there. I'm 47 years old and who knows, it might be the organ I play the last 20-30 years of my life. So I'm not taking it lightly to just 'find it a good home'. I have to keep myself in the loop for now. I just hate paying $60 a month to do it. Please, if someone, anyone has a good example of a 30 or 31 Orgatron I can hear I'd appreciate it. The one on Youtube right now does not count because he makes no registration changes. Thanks, I have to go clean carpet now-Paul

[dleeman]

I have a 1946 Wurlitzer Orgatron Model 30 that's exactly as you described - I'd like to restore it but can't find anyone remotely interested - it's a real beauty still and deserves to be heard again (safely).

[paulj0557]

Reviving this old very informative thread today. I am currently restoring my 1946' WURLITZER ORGATRON- ELECTROSTATIC KEYED FREE-REED organ. Btw it is easier to abbreviate 'electrostatic' with 'ES', though Wurlitzer never did. I decided to keep the organ since I was able to finally bring it out of my storage unit where it sat from my acquisition of it in early Spring 2011 until January of 2015, when I brought it home. A couple more years wouldn't hurt it, as this was just a continuation of it's dormancy. The person I got it from found it in a house he purchased which had been vacant since 1971. This man fashioned a new organ-to-tone cabinet 6-pin cable from the old one and tried to get it to play, but no luck. He sold me the series 31 organ and the 310 vibrato cabinet for $100! He had an open bid on his Craigslist ad, where I bid $300 and put it out of my mind. A couple months later I got a call from the seller telling me I could have it for $100 because nobody else made an offer and they wanted their garage space back.

I'll take a picture of this and post it in a day or so, but a very interesting aspect of my Series 31 Orgatron is that A2 to F4 in the center of the lower manual there are intentional lengths of screws that stick out under each key, and are clearly visible under the permanently open underside of the key desk so that when depressed they will contact either physical chimes, linkage to chimes, or switches for external chime activation. The CHIMES tab has no wires in it's stock organ condition, you can see the fresh unused switch terminals on the tab. Looking under the key desk where the screw heads are located there is a length of wood that comes down just barely past where the chime screws bottom out. So it does look calibrated for something. I have searched high and low for anything to do with Wurlitzer organ chimes, but always end up on the theater pipe organ chimes...heck, maybe these are the chimes they used??


I found a great spot in my Living room for the Series 31 Orgatron and it's 5' tall 310 Tremulent cabinet. Wurlitzer called it the 'VIBRATO SPEAKER CABINET' & the TAB on the organ is labeled VIBRATO, but inside the word 'TREMULENT' is stamped on the junction relay box. So someone at the Wurlitzer TONAWANDA, NY ( Niagara Falls) factory- a.k.a. THE WURLITZER THEATER PIPE ORGAN FACTORY was still in a Wurli' TPO state of mind! That, or they still had the old TPO 'Tremulent' rubber stamp laying around. [ have you guessed hunger for ANY information on this series of organs?

Unless Wurlitzer also produced early acoustic reed organs since the factory's inception in 1856, the only WURLITZER ORGANS built at the Tonawanda plant that I am aware of were the WURLITZER THEATER PIPE ORGANS from 1917 until WWII, and the ES Keyed Free-Reed 46'-53' and ES CONTINUOUS FREE-REED 53'-63' [ OF member, James corrected the presumed 61' end date as listed on Jan Giradot's Master Organ List ]. I would figure that since the Tonawanda factory was also a Juke Box factory, where all of the Wurlitzer Juke Boxes were vacuum tube amplified, that Wurlitzer would have also made their vacuum tube oscillator organs at this factory, but I'm not sure if the tube osc. organs were manufactured at the Mississippi factory- where I am certain that from 1964, anyway, that all of the remaining Wurlitzer organs were produced, beginning with the all-transistor 12 osc. divider models like the 4500,4300, 4520 theater, etc..

SOooo anyway, I have been testing and restoring the electronics in the 46' 31 Orgatron for the past week. I already restored the two 6431 amps in the 310 Vibrato tone cabinet( same as the 6420 amps in the series 20 ES reed organs speaker cabinet ( see RETROCHAD channel on Youtube), just the mounting brackets are different that's all).
The 310 cab has a 15" MAGNAVOX FIELD COIL SPEAKER IDENTICAL TO THOSE FOUND IN ALL OF THE LESLIE TALL BOY 30A, 31H, and 31W's rotary cabs. This 15" has no rotor below, although one could fit one under it. It would just be a few inches shorter, or you could raise the floor panel up without much trouble. There is also a 12" facing upward into the dual speaking, horizontally opposed, metal vane rotor [ see my demo video of the rotor with an old 78 rpm record playing through it...I had made the video for a friend who made retro videos of the 30's era]. Because I used the 310 cab on my 56' 4410 Wurlitzer continuous free-reed organ I quickly understood the appeal of such a "tame" rotor for the electrostatic reed organs. In 1946 the idea of a 'Slow speed Leslie' had yet to be commonplace, if at all. So perhaps the thinking was that a standard Leslie drum was just too fast for the ES reed organs. BTW, I mention the Leslie comparison here because it was indeed Donald Leslie who invented this dual metal vane rotor for Leslie, and although this was 1946 ( 5 years after the 30A's with their standard-forever-after single speaking horizontal rotary drum), it is documented by a close colleague who was around Don early on, that this dual speak metal vane rotor was without any doubt, Don Leslie's very first rotary design [ and note, it is an over-speaker rotor instead of an under-speaker rotor].
I will say though, that I am not fond of the 1/2" gap below the rotor and the speaker platform, where the sound can escape, hence lessening it's effectiveness. Upon closer inspection I see that the flat piece of metal that serves as the center axle support, it is just sitting on top of the speaker panel and not countersunk so the metal is flush. If I chisel out some of the panel surface below the flat axle support it should bring the rotor down closer so sound doesn't escape.

Anyway, I will post some images and document my progress. The FLUTE REEDS comprise 6 octaves and the VIOLA REEDS 3 octaves. The extra octave is either for PEDALS or 1' on the manuals.

The LOWER manual has 7 FLUTE TABS, same as Hammond console draw bars (A, B,C,D,E,RT's,A-100's,D100's,E100's, R100's) but minus 5 1/3' and 1 3/5'. There are 4 Orchestral Voices on the lower- DIAPASON, STRINGS, OBOE HORN, and CELLO. There is also a preset tab marked CATHEDRAL ORGAN on the lower manual.

The UPPER manual has ALL 9 FLUTE TABS identical to the Hammond console draw bars (A, B,C,D,E,RT's,A-100's,D100's,E100's, R100's). Interestingly there but one orchestral tab on the upper- an 8' FRENCH HORN. The only other 8' is CLARINET, which excludes an 8' FLUTE of any nature...
There is an ENSEMBLE tab on the upper, as well as the VIBRATO tab, which when depressed simply turns on the input audio to the upper rotary speaker. When the VIBRATO tab is off it kills the sound to the upper 12" rotary speaker. The upper rotor is always on and always spinning. Seems like a terrible waste of a great 12" speaker and two fully operating original coke bottle 6L6's wanting to be heard! Instead the upper speakers amp sits idle burning electric and putting wear on components...
I believe I will put a relay on said motor!

I have also decided to install my HAMMOND 3-SPRING NECKLACE REVERB and AO-35 REVERB AMP CHASSIS inside the WURLITZER 310 VIBRATO CABINET. Since the Necklace springs have excellent vibration resistant mounting brackets I don't foresee any resonant feedback on the springs. TANK reverbs and even 'oil reverbs' have more taut springs in comparison to the dangling 'necklaces', so Hammond tried their best to eliminate such issues. I can always take it back out. I can mount two 6X9"s end to end a couple inches apart pointing straight up, in between the two 6431 amp chassis, and a 4" above the giant rotor pulley. I will make a simple bracket to hold the open frame speakers, so they are easy to remove when servicing the amps. I might put a couple of 4" or 5" midrange speakers facing out of the sound vents under the 15" speaker. It should have a pleasant balance, of full range above with the 12" and mids and highs down below with the bass frequencies. I played bass in a band and used the highly acclaimed GUILD HARTKE 4-10" + center tweeter BASS CABINETS and that tweeter filled out the sound great. Btw I hated my Gallien-Krueger solid state bass head, so I promptly went out and grabbed the awesome AMPEG V4B! The V4B is identical to the greatest bass head ever- the famous SVT head, but the V4B is 'only' 100 watts. The V4 is the 6 string guitar version...I've modded a few of those babies, but the V4B is perfect bone stock! Btw these amps were made in the MAGNAVOX TV factory, so strange PCB mounted tube sockets, would cause issues on occasion. These amps weighed a ton!! So they used an ingenious ( to me anyway) shock suspension system on the amp chassis. Okay, so how did I get off on that.

Sorry for the book... and the repeats from previous posts, there is some new material in there somewhere. lol

[Guest]

Hi, I am new to the forum, and I am not sure I am navigating too well. If I am in the wrong tread, please give me some direction. My father worked at Wurlitzer, North Tonawanda NY. He was a highly skilled technician and he worked primarily on organs which used free reeds. I think I have the name right; they are brass and have a single springy like stripe in the middle. When the factory closed he was given some large items which were donated to a local museum. I still have scores of these brass reeds in envelopes by octaves, and I am trying to figure out if they are needed by someone restoring an organ. I have a person in India who wants them very badly, but his pitch doesn't add up. He wants them badly but doesn't want to pay for them. Thanks for your help, Joe

[jbird604]

Joe,

Welcome to the forum. This is probably a good place to talk about your father's career and the items you have. There are probably folks with an interest in those organs who will see your post and respond. I suspect some of our members will really enjoy learning anything you can share about your father's work and about the organ parts he had.

You might be able to sell the reeds by putting up a classified ad as well. These are of course very specialized items, and very few of the Wurlitzer reed organs are still in use, so you may need a lot of patience if you want to get rid of them.

[Guest]

Thank you. I will take a picture of the tuning bench part which didn't make it on the trip to the museum. Maybe someone can use it. Joe

[lcid]

Orgatron Series #20

I have a working Wurlitzer Orgatron Series 20, but I don't need any additional reeds. However, I'd be very interested in information about your father and his job at Wurlitzer. Thank you.

[james]

paulj,

The French Horn 8' and the Horn on the lower manuals of many of the ES models are nothing but a Flute 8' tone. Just think like the one set Hammond tone wheels those one set of Wurlitzer reeds could only provide a few tones so Wurlitzer made up for such as this via unique stop names.

Most of those orchestral names don't sound anything like the instrumental names on the stop tab. Read Eric Larson's info on these organs. BTW They don't even list a stop named Diapason or if it is a String that is the only label they put on the stop tab. I know on the larger 4602 model they have regular stop names on the stop, but like the Hammond they don't really sound like a true tone that is indicated.



James

[ChuckMcB]

Well I couldn't help but bring home this Wurlitzer series 21. It has the foot board only and was restored in the early 90s. I'm going to build a vacuum box system for my kimball based on the design this organ has. Now I have two.....

[JQA]

Congrats, that is a classic electrostatic reed organ, among Wurlitzer's first models... just beautiful! Did it come with the pedalboard? Also, this model requires an external tone cabinet (containing amplifier and speakers) - did it come with such a thing?

[lcid]

Congrats: I have Series (model) #20 in working condition with the service manual. Yours looks the same as mine; not sure what the difference is between these two models?.

[JQA]

The very first post in this thread mentions the difference between the 20 and 21 models. Its text is taken from Robert Eby's book "Electronic Organs" from 1953, which can be downloaded in full here: http://crasno.ca/articles/doc/EO_RLEby_1953.pdf

[ChuckMcB]

It did come with the pedal board but no tone cabinet. The tone cabinet cable has rca connectors added to the end so someone had it working with other equipment.

[JQA]

Excellent; with the RCAs it shouldn't be difficult to hook it up to practically any amplification system.