How do you listen to Old Music ?

[Marc Hildebrant]

MrRom92,

Before you try various size stylus, you should try some calculations regarding the pressure that the stylus imparts to the groove. In my Music Handbook, I describe the stress equations that I used to calculate the pressure using the original Edison Reproducer verses the 0.7 mil radius and 2 grams load that I used. The bottom line is that both methods are "close" to the same amount of PSI on the music groove.

Many of the equations (contact pressure/Hertz) have terms that are not linear, and even with a slight load, you can get high pressures with small stylus. If serious, I suggest some research to learn about contact stress.

This, of course, is not problem using steel needles on 78 Records!

Marc

[Governor Flyball]

MrRom92,

Before you try various size stylus, you should try some calculations regarding the pressure that the stylus imparts to the groove. In my Music Handbook, I describe the stress equations that I used to calculate the pressure using the original Edison Reproducer verses the 0.7 mil radius and 2 grams load that I used. The bottom line is that both methods are "close" to the same amount of PSI on the music groove.

Many of the equations (contact pressure/Hertz) have terms that are not linear, and even with a slight load, you can get high pressures with small stylus. If serious, I suggest some research to learn about contact stress.

This, of course, is not problem using steel needles on 78 Records!

Marc

I agree with Mark. The quality of sound appears to relate to both needle dimensions and area contact pressure. I have found a 3.5 mil radius tip stylus with a contact pressure or tracking force of about an ounce (28.35 grams =1.0 ounce) sounds very good on lateral 78's.

I would argue a vertical modulated Diamond Disc sounds better with a 3.0 mil stylus tracking at a couple of ounces than a 0.7mil stylus at 5 grams.

The problem is finding a transducer to translate the needle vibrations to an electrical signal at these stylus pressures. The ancient magnetic transducers had a very low compliance and only play lateral discs.

For lateral discs, I opted for the Astatic B2 which was an early Rochelle Salt cartridge. I remarkably found an 80 year old cartridge intact in an Astatic professional tone arm and it sounds really good. The frequency roll off is about 5kHz to 6kHz, so it removes the surface noise. (It is not the best for post 1950 78s because of the restricted cartridge frequency response).

I have successfully rebuilt a few Astatic B2's and have one fitted into my Capehart machine. It will play cleanly a wide variety of discs from early Victors and Columbias from 1908 through WWII with good tracking low noise and no apparent wear.

For the Edison Diamond Disc playback, I still rely on my A250. Although I have been looking at better electrical alternatives. The best so far to me appears to be the 0.7mil conical LP stylus tracking at 5 grams.