Groove widths of Edison discs vs. Blue Amberols

[pughphonos]

Some of you are going to know this right off the bat. Are the groove widths and other configurations on an Edison Diamond Disc identical to those on his Blue Amberols? Probably not, but thought I would ask. Was just wondering if it would be possible to play a Diamond Disc using a Diamond B reproducer off an Edison cylinder machine--if one could secure it in place properly and securely, and with the right pivot points, of course.

(This sort of repurposing insanity is my specialty).

Ralph

[52089]

I don't know the specific groove widths, but since the Blue Amberols are 200 threads per inch and the Diamond Discs are 150 threads per inch, it's a safe bet that the groove widths are different.

[OrthoSean]

The TPI may have been different, but I'm 90% certain the stylus radius was the same for both from what Steven Medved relayed to me some time back. I've used my ACT 4 minute stylus in my standard setup for transferring Diamond Discs many times in the past and it tracks and plays many just fine with no groove damage FWIW.

Sean

[Lenoirstreetguy]

I think Sean is right. The tip radius of both sylii is identical, as I recall. I've played a Diamond disc with my Diamond B or part of one by holding the reproducer in my hand. Hardly scientific but it worked.
Jim.

[VintageTechnologies]

I also recall reading that the groove pitch is different, but that the stylus radius is the same. I have also held a Diamond B reproducer over a DD without ill effects. In fact, the stylus pressure of a Diamond B is less than a DD reproducer, so no harm should be done.

[gregbogantz]

I think the groove widths are different. Rather, they have different radii which require different playback stylus sizes. I tried what was suggested above several years ago, using an amberola reproducer to play a DD and I inflicted instant damage to the DD. Which would indicate that the amberola stylus was smaller than the DD groove. But I can't put my finger on an factual evidence of this. I don't have the means of measuring the radius of these styli (you really need a shadowgraph setup to do this right) so I can't confirm this first-hand, but I would suggest researching this further before you commit to playing a DD with an amberola setup. Or maybe try it with a junk Hawaiian DD that you don't mind screwing up. Expert Stylus in England should be able to give the definitive answer since they make both types of styli.

This is not an issue when using a modern cartridge with light tracking force. At 10 grams or less, a smaller stylus will not damage a larger groove.

[pughphonos]

Thanks, guys. Seems like quite a few of us have been curious about this and have had a try with a "junk Diamond Disc." I did so a few hours ago and the reproduction seemed clear--and I could not hear nor spot any damage. I'll continue cautious experiments. Of course it would be very interesting to hear a Diamond Disc reproduced through an orthophonic horn. Someone has already posted such an experiment on You Tube, but he used a Brunswick Ultona reproducer that had been altered to attach to the Victor tone arm.

You're all going to think I am the "Frugal Gourmet" of antique phonographs: trying to pry as many usages out of as few machines as possible. I'm not driven entirely by cheapness. Once you've been in this hobby for awhile you realize that even "back in the day" (1910s-1920s) everyone was cooking up adapters for the various makes of phonographs, and that the situation was very fluid. So it's just another way of recreating the experience of the times to work some adaptations oneself. The manufacturers came up with hundreds of adaptors, not all of which have survived; and the handymen who owned phonographs produced (I bet) thousands for their own private use.

I do own a Rek-O-Cut turntable (see, I'm not ALL that poor) and can play all my old records electrically, with correct styli. But one can't beat trying to make do with the acoustic machines "from the day."

BTW, I'm continuing to work my own adaptation of Paul Dodington's device (using a plastic ½" pipe elbow that enables a Victrola orthophonic to play Pathé vertical records). I'm working out the final kinks and will submit a video to you all sometime next week.

Ralph