The Edison Diamond Disc Phonograph - History, Identification, Repair

I. A brief history

Every story has a beginning, a middle, and an end.

A storyteller usually starts at the beginning of the story, and works his way to the end.

The beginning of this story is the original Edison tinfoil patent of 1877.

Once in a while, the storyteller starts at the end of the story and works his way back to the beginning.

The end of this story is the Great Depression of 1929.

But the story of the Edison Diamond Disc Phonograph really starts in the middle, in 1910.

Diamond Disc feedEdison B60
Left:This rack and wheel constituted the mechanical feed of the Diamond Disc phonograph. Right: The A60 (later B60), a machine without a lid, dates to the inaugural Diamond Disc entries of 1912.
By that year, flat disc records were far outselling cylinders and Edison, by choice, was the last man standing in a moribund cylinder market. It was patently evident that the future lay with the flat disc record, and so Edison, while publicly pooh-poohing the disc talking machine, began conducting secret research into a disc machine of his own.

It wasn't that the technical difficulties of a flat disc phonograph had ever been insurmountable. In fact, Edison's 1877 patent had offered visions of the phonograph both as a cylinder and a disc machine, but the state of recording science in the 1880s and 1890s had favored the cylinder phonograph with its mechanical feed advancing the reproducer at a constant rate of speed. In addition, the cylinder phonograph presented the capability of home recording, although the shaving knife for home recording had been dropped on most Edison models with the demise of the Model A machinery in 1904, as the phonograph came to be recognized as a medium for entertainment rather than for business.

By 1910, however, most of the technical problems of recording on the flat disc record had been solved, and the advantages of the flat disc record versus the cylinder were manifold: the discs were louder, more lifelike, less fragile, easier to store, and enjoyed a longer playing time of around three and a half minutes.

Edison, like every other business that had tried to enter the flat disc market, would have to contend with a number of patents owned by the Victor Talking Machine Company, primarily the needle-in-the-groove patent to advance the record, and the tapered tone arm patent to enhance the sound. These patents were ruthlessly enforced by Victor's legal department.

However, since Edison already had rights to hill-and-dale (as opposed to lateral) recording and used it on his cylinder machines, the obstacle of the Victor needle-in-the-groove patent could be bypassed.

Edison put his chemist Jonas Aylsworth to work. There was a lot of research going on at this time into phenolic resins, and Aylsworth came up with a composition he called condensite, which was similar to another resin that later became known as bakelite. The new Diamond Disc records would be a laminate, a condensite core with an outer layer of lacquer. The records were a half inch thick because they had to be absolutely flat in order to accomodate hill and dale recording.

Extensive experimentation was performed to develop a reproducer; what resulted was a quite heavy overhanding weight with diamond stylus, connected by a silk (or sometimes cotton) linkage to a cork-stiffened, rice paper diaphragm. The diamond stylus, which was also used in late Amberola reproducers, was ground to .0075 mil. in order to ride in a disc cut to 150 grooves per inch at 80 revolutions per minute.

This reproducer was far superior to anything Edison had ever done before: loud, lifelike and warm; far superior to his cylinder reproducers which still mangled select phonemes of the English language. It was the equal if not the peer of Victor and Columbia flat disc reproducers.

Yet there was something else that ensued from all this business of evading the Victor patents and that was the price. Additional components had to be added to the mechanism, a mechanical feed to advance the reproducer, a horn that pivoted and could be raised and lowered, and so on, and all these components added to the cost of manufacture. When the Diamond Disc phonograph was introduced in 1912 the lowest price model sold for $60; by comparison, Victor's lowest price model in 1912, the Victrola IV, sold for $15, and bear in mind that this was in 1912 dollars.

The new Diamond Disc phonographs were unveiled in 1911 but didn't really work their way to the dealers until late 1912. The initial models included the A-60, A-150 and A-200. In 1916 the Diamond Disc was renamed 'The New Edison.' Various additional models were introduced during the following years, particularly a slew of models in 1919 such as the C-19 and L-19. The C-250 of 1915 was designated the Official Laboratory Model and was fitted with a pretty plaque announcing the same; it is unnerving how 90 years later some owners of these machines still cannot be dissuaded of the belief that they are in possession of the very machine that sat in Edison's experimental workshop.

The Diamond Disc phonograph was also the subject of one of the greatest campaigns in advertising history, beginning in earnest around 1915: the tone test demonstrations. A number of Edison vocal recording artists were trotted off to auditoriums around the country. The artist, and a Diamond Disc machine playing a recording by the artist, were placed on stage behind a curtain or in a darkened hall, and the artist and the machine would alternately perform. The audience was challenged to tell the two apart. In every case, it was reported that the audience couldn't tell the difference!

In 1926 Edison developed a long playing reproducer capable of playing a record 40 minutes long, cut to 400 threads to the inch. A series of console machines was introduced to play the new records, and an adapter kit was sold to convert prior Edison machines. The long playing Edisons were not a commercial success, perhaps because they were too far ahead of their time; one often sees the machines, less often the reproducer, and far, far less frequently the records, because very few titles were pressed.

In 1927, in response to the increased frequency range of the Orthophonic Victrola, Edison introduced a machine dubbed the Edisonic. The Diamond Disc reproducer was modified into the New Standard Reproducer, primarily through increased weight and a spring tension linkage. There were two Edisonics, the Beethoven and the Schubert, both shared the same horn but the Beethoven had the larger cabinet.

The Diamond Disc phonographs sold well, but never as well as their Victor counterparts. The cost of manufacture was higher, so profit was lower. Although some beautiful cabinet work was done such as the Louis XV Diamond Disc, in general the cabinetry was considered inferior in construction to the Victrola. Without an aftermarket adapter, the machine was incapable of playing regular 78rpm lateral cut records, and Edison was afraid to sell an adapter for patent reasons. And until very late, with the introduction of the 52000 series of records, the choice of titles lacked modern music and jazz, and was served to the tastes of Edison's rural customer base. All this conspired toward the demise of the Diamond Disc phonograph, but even more so what conspired was what was happening to the phonograph industry in general in the late 1920s, the availability of free music over the radio. And you already know the end of the story: the Great Depression of 1929.

If you want to learn more, the standard reference is George Frow's book, The Edison Disc Phonographs. Your library may be able to get a copy on inter-library loan.

II. Edison Diamond Disc Phonograph Model Identification

The identification of Diamond Discs models is absurdly simple. Sometimes Edison's copywriters conjured supplemental designations such as Queen Ann or Chippendale which reflected the style of the cabinet, but every machine also had an alphanumeric identification, and in most cases that's all you need to know.

So perform the following easy test. Almost every machine has a nameplate. Look at the nameplate and ye shall know the model.

Louis XV Edison
The Louis XV Diamond Disc was an outstanding example of the cabinetmaker's art.
To help you out a little more, here are some cryptographic keys:

Key Number One:

The first series of machines had a letter followed by a number. The letter was the style of motor. A represented the first style of motor, B the second style. The number represented the original price in dollars.

Example: A100. You have a model A100. When first introduced, it sold for $100.

Key Number Two.

You have the number 19 on your nameplate. This means that the machine was first introduced in 1919.

Example: S19. You have a model S19. Keep on reading to learn what the S stands for.

Key Number Three

What some of the other stuff might stand for.

C 150 Sheraton
C 200 Adam
C 250 Chippendale
W 250 William and Mary
D 25 Jacobean
C 450 Century Adam
H 19 Hepplewhite
L 19 Louis XIV
S 19 Sheraton
BC Baby Console
LU London Upright
LC London Console

I have pictures of a few of these machines on the Antique Phonograph Identification Guide.

III. A few notes on the records

Warning. There are things you can physically do, but hold the potential for unhappy consequences, such as walking down the middle of a busy highway. Here are two more warnings: don't play 78rpm shellac records on your Edison machine, and don't play Diamond Disc records on a regular Victrola. Edison styli bob up and down. Most 78rpm styli wiggle in the side of the groove.

Don't play Pathe records on your Edison machine, either. It's true that Pathe manufactured vertical cut records for a long time, but Pathe records made use of an exceptionally wide groove and a ball type sapphire stylus.

If you want to play regular 78rpm shellac records on your Diamond Disc machine you'll need an adapter. Besides presenting patent obstacles, Edison was afraid that lateral cut adapters would cut into Edison record sales. There were several companies that manufactured aftermarket adapters, the Kent adapter being perhaps the most popular. The adapters are quite easy to use. Just twist the knurled knob at the small end of the horn and the reproducer will pull straight out.

Here are a few graphic notes on the Diamond Disc labels. Not all are depicted.
Half tone labelPaper labelStar label
The half tone label dates from the inception of the Diamond Discs until around 1921. The white paper label with black type dates from 1923 . A prior paper label used white type on a black background. Starting 1919 the records were no longer called records. They became 'Re-Creations.' The star on the label didn't exactly indicate that this was a special record -- it was a secret message from Edison to his dealers that he thought the title was likely to be a slow seller.

IV. Edison Diamond Disc repair

The Diamond Discs phonographs.are suprisingly rugged and durable machines. The only major problems I've run into over the years have been broken springs and reproducer repairs.

The spring is quite thick as compared to a Victor mainspring, and I wouldn't suggest that you replace it yourself. If you don't know what you're doing you may wind up looking like the victim of a bout with Muhammed Ali in his prime. Send the barrel out to a professional for replacement.

As to the stylus, the diamond point was originally electroplated to the shank, so you can't just replace the stylus, even if this was a good idea. If you can do it, put your stylus under a jeweler's loup. The stylus should be pyramid shaped, and come to a sharp point. Even the slightest chip on the stylus will affect the sound. Also, the silk linkage commonly frays with age or pulls out of the diaphragm. A reproducer repair and rebuild isn't cheap -- the diamond stylus alone now costs $100 -- but the good news is that the parts for this reproducer are still available, that the stylus should last a lifetime if you don't abuse it, and that you will be amazed by how ineffably beautiful your records will sound.

As you might have guessed, we offer reasonably priced Diamond Disc phonograph repair; feel free to contact us for an estimate.

Copyright 2015 Lynn Bilton

Lynn Bilton
Box 435
Randolph,OH 44265
330 325-7866


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