Edison Diamond DIsk

[tmea]

OK, I know the answer to this question but here it is anyway: Why can't you play an Edison Diamond Disk on a regular victorla? Yes, it was not made for the victrola and with a vertical cutting instead of horizontal cutting and thinner groove it represents a variant on the technology. The Edison record was not meant to be played on machines designed for playing horizontal cut records.

None the less.... They will play. They don't sound great but are OK. The logic behind my question; how does playing these Edison records on an ordinary victrola destroy the record? My thinking:

1. The victrola's steel needle is considerably softer and wider than Edison's diamond needle and therefore much less damaging to the Edison record's hard surface. This is simple science.

2. The much wider tip of the victrola's steel needle rides shallower in the Edison records groove barely touching the vertical cut sound data at the bottom of the groove (bringing much lower volume and small reduction of sound quality).

Considering these two points I do not see the problem with playing the Edison Disk on any other type of machine. I can however see great damage occuring by playing standard victrola records on the Edison machine. These softer records being played with both a sharper and considerably harder needle has to be damaging.

What are your thoughts? I'm not a fan of conventional wisdom not supported by facts or science. Is there something I'm not considering? I really want to play my sole diamond disk on my Columbia Graphonoa. Why not?

Tom

[Jerry B.]

The pounds per square inch weight of an Exhibition reproducer with a new steel needle is incredible. Try lifting the reproducer with a new needle by using a finger that has no callous. I tried it years ago and couldn't do it. You can't cheat. You must lift at the point of needle when it's pointing directly at your finger. I suspect that tremendous weight is what destroys a Diamond Disk record when played on a Victrola. I suspect there's a more scientific explanation but this I understand. Jerry

[gramophoneshane]

My unscientific observations in the past have been that the instant you lower a new steel needle onto a DD, the needle will start cutting the condensite, leaving brown lines & permanently damaging the recording.
If you really REALLY have to play your DD, I'd highly recommend going to a sewing shop & buying a $2 ball point sewing machine needle, designed for stitching stretch fabric, and cutting it to length. The end is rounded rather than pointy, so it will not cut the record surface until it's been used many times & has worn enough to start doing damage.

[HisMastersVoice]

It's definitely a weight issue. On a DD machine, only the weight of the stylus bar is resting on the disc, which is very light. The reproducer on a Columbia Graphonola is even heavier than a Victor, since the weight of both the reproducer and the tonearm rests on the record. Columbias are even rough on 78s. I suspect that if you play the DD on it, it will be it's last.

[gregbogantz]

There are two main reasons why you should not play DDs with steel needles in a lateral reproducer. First, the steel needle starts out with a sharper point when new than the spherical shape of the proper DD stylus. This steel point very quickly wears down in a few revolutions of the record to produce sharp edges. The condensite surface of a DD record is very brittle and scratches much more easily when abraded by a sharp point. Evidence of that scratching is the brown powdery appearance of the record surface when attacked by a steel needle. At which time, the record is ruined. The spherical shape of the DD diamond stylus wears very slowly and continues to present a smooth contact surface to the record even after many plays.

But also quite important is the lack of compliance at the stylus tip when the wrong reproducer is used. A vertical reproducer such as the Edison is designed to allow vertical motion of the stylus which reduces the stress and wear on the record with vertical modulation. A lateral reproducer such as a Victor is VERY stiff in the vertical direction since it is designed to allow for lateral motion of the needle. Such stiffness adds considerably to the stress on the record groove when the modulation is vertical. Likewise, the Edison reproducer is not designed for lateral modulation and presents the very high entire mass of the tracking weight to the stylus tip when subjected to lateral modulation. Using a DD reproducer to play lateral records will wear the record quickly due to the lack of compliance at the stylus tip to lateral modulation. In both of these mismatched cases, reproduction is audible but the quality of the sound is quite poor because the reproducer is not designed for the modulation direction of the mismatched records.

Tracking force per se is not the issue. The Edison standard DD reproducer tracks at about 110 grams at the stylus tip compared with about 100 grams for a Victor Exhibition and 120 grams for a Victrola #2. And the Edisonic DD reproducer tracks at 150 grams which is even more than the Victor #5 orthophonic at 135 grams.

[tmea]

OK all. Thanks very much for all of your information. I am both educated and convinced. Very intersting to me and all makes sense. I'll have to research the Edison machine so I can visualize the differences you have described. Thanks for the answers and information!

Tom