Quote from: Paul Perry (Frostwave)
I don't think any of these systems have the actual SPEAKER rotating, because you would need sliprings to feed the signal to them & get hellish noise.

If I'm not mistaken that is precisely the arrangement Ansil is using in his design:

http://www.geocities.com/austenfantanio//rotocabtypethang.htm

Minus the spinning speaker and you have the basic design of the Fender Vibratone:
http://mywebpages.comcast.net/vrbass/vibratone/

Kerry M

Thanks for clearing that up Bwanasonic! and thanks for the great link!
I still think it would be simpler to spin a radio mic in front of a speaker to get a truly sickening effect..

Has anybody tried to spin piezo tweeters???

They are lightweight, are available with various (though variation is limited) radiation pattern, and are cheap. Some new ones go well down under 2 kHz. Which is somewhat drawback and limitation of course.

Quote from: bwanasonic

Quote from: Paul Perry (Frostwave)
I don't think any of these systems have the actual SPEAKER rotating, because you would need sliprings to feed the signal to them & get hellish noise.

If I'm not mistaken that is precisely the arrangement Ansil is using in his design:

http://www.geocities.com/austenfantanio//rotocabtypethang.htm

Minus the spinning speaker and you have the basic design of the Fender Vibratone:
http://mywebpages.comcast.net/vrbass/vibratone/

Kerry M

actually that is what i was doing and yes if you dont' lube it and try to run it wide open it can be noisy  but i haven't had a problem with it yet. i am using some graphite lube that i used to use on the wooden car wheels from scouts some 15+ years ago.  its the same thing i used to keep the pots that spin in the drunk spider on my site from cracking up.

Quote from: Paul Perry (Frostwave)
I don't think any of these systems have the actual SPEAKER rotating, because you would need sliprings to feed the signal to them & get hellish noise.

Hmmm.... Have you ever looked inside a video? The read/write heads are on a rotating drum type thing. The signal is going in/out of them with a kind of transformer where the coils are around the axis. One on the stationary part and one on the spinning part. This kind of assembly could work in in the spinning speaker stuff.

Some time ago I thought of making a small spinning speakker thingy from parts of an old video. I wouldnt have put the speaker to spin around it's axis. I wanted it to spin little differently but balancing it would have been a problem.

I hope you guys understand what I'm trying to explain... English is not my native language...

Quote from: ElektrojänisHave you ever looked inside a video? The read/write heads are on a rotating drum type thing. The signal is going in/out of them with a kind of transformer where the coils are around the axis. One on the stationary part and one on the spinning part. This kind of assembly could work in in the spinning speaker stuff.
...

Absolutely, perhaps you could base it around an AC electric motor..
there aren't any sliprings to worry about there.

Real leslies didn't have the actual speaker spinning though...they just had the speaker pointing into a spinning horn.  At least you don't have to worry about slip rings n' stuff if you're just spinning a horn.   All you'd need is a regular elecrtic motor and a speed control connected to the spinning horn.

The electronics would be simple enough;  Just use the guts from one of those micro-mini amps for the input amp and speaker, & something to control the speed of the motor.  You could use a Meccano pulley to mount the spinning baffle on and make a belt drive with a small motor.

Hey, I just suggested you make a mini-Vibratone  :oops:

How about a speaker array, with maybe six speakers facing outward from a center point, and instead of spinning the speakers, have the signal go from speaker to speaker to create the rotating effect? An expensive and heavy design if you use expensive and heavy speakers, but it might yield interesting reults with lighter inexpensive speakers. Could also use a second array of piezos and split the signal to each array. Not sure what the best way to implement the electronics would be...

Seems pretty obvious, my guess is someone's tried it

Kerry M

Guys:

This is what I initially suggested (more or less)!  Ansil's done a lot of the work already, and R.G.'s suggestions did more of it!

bwanasonic:

Of course someone's tried it!  That's where the Motion Sound, Cordovox, RVS, Vibratone and Yamaha tremulant systems came from.  Unfortunately they're all big or heavy or expensive or hard to find -- which is why I was broaching the idea of making a small tremulant in the first place.  The thing is, I don't think anyone really cares about making a cheap, small tremulant -- or even thinks it can be done.  Personally, I think it can, and I think our "design by committee" approach has done it!

bobbletrox:

The Vibratone spins a styrofoam "squirrel-cage" affair around a speaker and vents the sound through baffles in the top and in the sides toward the top.  It looks kind of like a vinyl-covered Leslie with metal grates in it.

How would having a normal full range guitar speaker being placed in place of the bass sound?  If there is no crossover, would the effect be a tremolo on the bassier tones due to properties of bass, and the chorus-phasey on most of the tones?