The use of modern techniques
to improve cylinder playing

I - THE PROBLEM

The first cylinder phonographs were intended to incorporate, in the same machine, the recording and playback of sound.

The success of the phonograph created a strong demand for prerecorded cylinders and the two functions, recording and playback, were dissociated, bringing:

• The professionalization of recording, making use of the latest techniques of the time.
• A massive spread of machines for playback only, made at lower cost, and often of mediocre quality.

Consequently, playing cylinders on the phonographs we have today, even when they are in an excellent state of conservation, does not permit us to restore all the information recorded on these supports. One may make the same remark for discs, ecpecially microgroove discs, the information recorded being only partially recovered, or even deformed by low-end players.

These observations make us ask the following question:

How can we, given the cylinders we have, and with the technology of today, read all the information that has been recorded?
In other words, how can we use the technological resources of today to recover from a support that dates a hundred years back in time, a sound as close as possible to the one emitted by the performer, and in any case very significantly better than that obtained using the best players of the time?

The answer hinges on two points:

• Constructing a playing device using the techniques known and mastered today, especially those permitting to turn the analogue information on the cylinders into electric signals.
• Processing the information gathered to eliminate noise and only restore the useful sound, the sound that at the time was intended to be preserved.

The two points are bound tightly together and one can not be conceived without the other. The first one mostly makes use of mechanics and electronics while the second one uses computer technology and the almost limitless resources of digital sound processing.

Even if the final result can only be fully appreciated after processing the sound, we will here only concern ourselves with the first point, that is the description of the player. It is an important point because it permits extracting the sound message engraved on the cylinder. It is very technical and leaves little room for subjectivity or improvisation.

The second point is a lot more delicate and in some cases poses problems of interpreation. Contemporary technology lets us process sound and change it to the point of obtaining "virtual" but perfectly plausible results that have never existed, for instance, to make Caruso or Nelly Melba sing Yvette Guilbert's success "Le fiacre".

Aside from there ethical problems, which by far exceed the limits of this article, the description of the techniques of sound processing require a competence that the author of these lines holds only in very small part.

II - THE CHARACTERISTICS OF A PLAYER
BUILT WITH MODERN TECHNOLOGY

A modern player, whatever it may look like, and whatever its finish, should have the following characteristics:

1. Accept cylinders of different lengths and diameters,
2. Spin the cylinders at speeds that may vary greatly from one brand to another,
3. Read the cylinders as they were recorded, that is with an arm that moves at right angles to the cylinder axis, thus tangentially to the groove,
4. Being equipped with a magnetic stereo pickup, with the possibility of applying to the cylinder a pressure of up to some ten grams,
5. Accept styli of very different types,
6. Being able to change the position of the cylinder axis in several directions, especially the horizontal,
7. Being equipped with a device to correct the defects of some cylinders, such as excentricity and variations in thickness,
8. Give an output signal compatible with the common Hi-Fi norms.

It is obvious that these characteristics are not all equally important and that some may be omitted. What is listed above are the ideal conditions. As we will see, especially the changes in rotational speed can be very effectively brought about by digital sound processing.

III - SOME REMARKS ON DIGITAL SOUND PROCESSING

For some years now, we have known how to digitize and process sound. What used to be reserved for professionals at very high cost is now accessible, at a more decent price, for home use.

There are several programs on the market, not all performing equally well. Some have functions that approach those of the professional tools. In particular, we may mention the program Sound Forge, which in its most complete version permits an efficient restoration of old recordings.

We will not here enter into the details of sound processing, which is relatively complex and requires a fair amount of practice to end up in an interesting result.

The main functions used are the following:

1. Transformation of the stereo signal to a mono signal by choice of the best channel (recordings are not symmetrical) or by addition of the two channels using the difference between the channels
2. Modification of the signal to eliminate errors such as the repetition of the same track on a deteriorated cylinder.
3. Digitally changing the speed of rotation in half-tone steps.
4. Attenuation of surface noise by several functions in the program intended for this task. This is the most delicate part of the work, as the program can not always distinguish the noise to remove from the sound to keep. Too intense processing will generate spurious noises (echo, cave effects ...) which are contrary to the intended result.
5. Surgical type removal (point by point) of noise generated by cylinder defects (holes, scratches, cracks).
6. Attenuation of spurious frequencies emanating from the recorder when recording the cylinder. Eventually, and respecting the original sound and elementary ethics, the replacement of short inaudible passages by identical samples of better quality taken from different parts of the same cylinder.
7. Normalization of the output signal and recording of the final result on hard disc, audio CD or cassette.