Can somebody explain to me how this Ultraphone works?

[Tinkerbell]

This Ultraphone has two tone arms, reproducers and sound boxes which are supposed to play at the same time... yet only one turntable. Does is require a specialty disc/record?

eBay Item #270627117587

[Starkton]

You don't need a special record. The acoustic signal emanating from the second reproducer is a little time-delayed, which is inaudible. Amplified tones should result from this arrangement - a slimmed version from the Triplophon we discussed elsewhere.

In early 1895, Albert Költzow of Berlin patented a phonograph with two reproducers very close behind one another to amplify sound. Leon Forrest Douglass' polyphone attachments of 1898 worked after the same principle.

[estott]

I'm not so sure the time delay is inaudible. I've never heard one of these things but I once rigged up my own version, the needles ran together in the same groove almost touching. In a vocal record the impression was of two singers in exact unison, it was less noticable with dance music.

[Starkton]

I have listened to an upright version of an Ultraphon and I cannot remember to have heard a difference. Perhaps the recording wasn't demanding enough.