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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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15th Jul 2022, 10:59 am | #21 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Odd audio puzzle
That Rotofon, with its speakers on the "fan blades" and connected by a slip ring commutator, is something special!
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15th Jul 2022, 11:36 am | #22 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,676
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Re: Odd audio puzzle
I knew about the Leslie speaker, but not the Rotofon.
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-- Graham. G3ZVT |
16th Jul 2022, 10:43 pm | #23 |
Pentode
Join Date: Nov 2015
Location: Witney, Oxfordshire, UK.
Posts: 225
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Re: Odd audio puzzle
Hopefully not wandering too far OT, many years ago I came across a real organ (i.e. one with wind and pipes) that employed what appeared to be a rather poor attempt at a tremulant effect. [The tremulant is typically applied only to the Swell division of the instrument, being the pipes controlled by one of the keyboards (manuals) that are enclosed in a wooden box fitted with a set of shutters that is operated by a pedal.] In this instrument was mounted in the top of the Swell box a pair of paddles on a horizontal shaft, turned at perhaps 2 rpm by an electric motor.
The resultant eddies from this device would presumably produce fluctuations in air pressure at the ends of the pipes, thus tiny AM and FM effects on the sound. I will say that the effect was far from convincing compared with the more usual tremulant that, I believe, modulates the air pressure supplying the pipes. Last edited by GroovyG; 16th Jul 2022 at 10:53 pm. |
17th Jul 2022, 6:00 am | #24 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,676
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Re: Odd audio puzzle
Don't you mean two revs per second, 120RPM?
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-- Graham. G3ZVT |
27th Aug 2022, 6:17 pm | #25 |
Pentode
Join Date: Nov 2015
Location: Witney, Oxfordshire, UK.
Posts: 225
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Re: Odd audio puzzle
Graham / rambo : of course you're correct. Doh!
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