Edison Diamond Disc Tuning Records

[Victrolacollector]

What was the purpose of the tuning Records. Were they for setting speed? or were they for adjusting the reproducer? and to what? Did it check for a bad diaphragm?

I just do not understand it.

[52089]

They were for setting speed.

http://forum.talkingmachine.info/viewto ... ing+record

[fran604g]

They were provided by the Edison co. to calibrate the turntable rotational speed. The record provided a tone-pitch (an "A", if IIRC) that would be be matched to the tone of a pitch pipe at a specific frequency, thus determining the correct RPM of the turntable.

There's a great past discussion on the topic here: http://forum.talkingmachine.info/viewto ... ing+record

Fran

[fran604g]

They were for setting speed.

http://forum.talkingmachine.info/viewto ... ing+record

HAH! You beat me to it!

[VintageTechnologies]

The phonograph dealer was issued a tuning record and tuning fork. The record played a steady pitch throughout. By adjusting the speed to tune the record's tone to the tuning fork, 80 rpm was quickly and easily set.

[fran604g]

The phonograph dealer was issued a tuning record and tuning fork. The record played a steady pitch throughout. By adjusting the speed to tune the record's tone to the tuning fork, 80 rpm was quickly and easily set.

I don't want to be disagreeable, but the instruction found for this record clearly states a pitch-pipe was to be used. http://forum.talkingmachine.info/viewto ... 18#p114718 the image below is from this post.

Fran

Tuning Pitch Insructions.jpg (175.65 KiB) Viewed 1534 times

[PeterF]

I actually got the specified pitch pipe for this very purpose, and when I get around to trying it out on a DD machine with the tuning record, I'll let you know about the experience.

[Victrolacollector]

Thanks for all of the clarification. I actually never knew it was for speed setting. I am so accustomed to the speed strobes that we use today.

[fran604g]

Within the linked post above is Coyote's link to his video recording of his Tuning record being played while he uses a pitch-pipe for comparison. http://forum.talkingmachine.info/viewto ... 575#p31575

Within the same thread, the explanation provided for "International A" tuning by De Soto Frank is fascinating. http://forum.talkingmachine.info/viewto ... 340#p29340

I wonder if anyone has used an RTA (Real Time Analyzer) as a pitch detector and an accurate RPM calculator to precisely measure the recording to determine which frequency the Edison co. actually provided?

I used a pitch detector app on my Android MotoX (2gen) while playing his video, here are my results:

The signal provided by his playing of the recording on his C 19 without the pitch-pipe being used is around 435 Hz. When both signals (the Re-Creation and his pitch-pipe) are heard simultaneously, the combined signal is detected at 440 Hz, suggesting his pitch-pipe is indeed A=440 Hz as he stated, and my pitch detector app is measuring his pitch-pipe frequency accurately.

When viewing the Edisonic Schubert portion of his video and only the Schubert signal is being detected, it is measured at 440 Hz. When the pitch-pipe is introduced, the combined detected frequencies are very closely around the 440 Hz mark.

This suggests that the C 19 is playing at A=435 Hz, and the Schubert is playing at A=440 Hz.

Using the same app on my Android, I measured a family heirloom pitch pipe that I have here consistently sounding at 444 Hz. (original box labeled: "Violin/Mandolin -- Pitch-Pipe -- Wm. Kratt -- A-440 -- Made In USA"; likely from the late 1930s or early 1940s). This suggests that older pitch-pipes (certainly mine) may be out of tune, or possibly weren't accurate to begin with.

So conclusively, my own analysis of Coyote's video recording is revealing, but inconclusive.

It was fun, though.

Fran

[WDC]

I did check the actual frequency some years ago at 80 rpm and came clearly to 440 Hz by spectral and waveform analysis along with audible comparison to a digital 440 Hz sine wave.

But these tuning records are often also somewhat excentric and not as precise as they should be for this purpose. This would correspond perfectly to the improper tuning of period pich-pipes.

I just realized and old typo in that one thread as Chuck had remarked, so yes, 440 is perfectly correct.