mini amp at the end of a rope

[bwanasonic]

In the quest for Leslie-like tones, I'm wondering if anyone has maybe put a smokey or equiv. small amp on a turntable or swung it on a rope for * swirly* sounds? Pignose on a string, etc... Any schematics for a *miniature leslie * designs ? A Miniature Motion-Sound amp basically....


Kerry M

[gez]

I still haven't got round to doing this yet, but an easier way to it would be to buy a little motor, attach a disk to it with holes drilled in it, then stick it in front of the little speaker.

I also want to have a go at doing this for the driver of a talk box - should be fun!

PS Set the motor up for variable gain

[Rodgre]

I've done the opposite in the studio, by swinging the microphone. Dangle it from the ceiling, over an amp, and let it swing around while you take that amazing one-take solo!

Roger

[Nasse]

I think somebody mentioned few weeks ago some kind of rotating system made of lightweight polystyrene foam, that spins around stationary speaker. Because of small mass you can manage with smaller motor. Last time I visited a local flea market there was some cheap old home organs, and under the hood was 8 inch speaker and "leslie" thing...

:twisted: I believe our local public library has one old book, in which there was another electronic solution for rotary speaker simulation. Construction article described a system of 8 small speakers in a circle and 8 amplifiers, which were not rotating but audio signal was electronically circulated round and round the ring. But I dont recommend the book, it is said most of the circuits dont work very well. :twisted:

:idea: Hmmm... if making real rotary speaker is so difficult... and someone talked about microphone... If you cant play live trough real rotary speaker, could it be possible to do the sound-processing when recording!  :roll:  How bout a stereo microphone, and put that rotating thing with holes over the mic...= leslie microphone, should be smaller and easier done!!  Or I need a holiday  :x

Well, I have this just one more idea how to record your moving-in-the-air amplifier: One old and quaranteed to work method of getting good larger than life surround sound for your stereo track and very cheaply is to take two low-cost omnidirectional electret mics and place them middle at opposite sides of a sheet of plywood about 1 square meters, just connect the mics to your stereo channels and you get very nice stereo sound. I have made life-like recordings ambulance and motorcycles passing by. Just make this recording assembly and put yourself with your amp and guitar on a spinning chair

[Paul Perry (Frostwave)]

I suggested using a rotating radio mike a while back, but i don't think anyone tried it Could be fun to use a RC car as well!

[Quackzed]

if you see an organ on the side of the road  rip out the rotating speaker!
its free...
it's a rotating speaker with (usually)2 ac motors!
sure, you don't see them every day... but when you DO they are usually there for a while...(hard to fit in a garbage truck!)
just a rotating wood(old) or styrofoam(new) cheeze wheel looking thing in a wood frame with a speaker.
the "leslie thing" in some home organs IS a leslie(not LESLE brand but a rotating speaker..)
usually theres a tube amp in em too! the organs that is (if you know your way around HIGH VOLTAGE tube circuits you could make a guitar amp...)
plus, analog organs have TONS of circuitboards (resistors,orange drop caps,mallory caps,mercury switches,diodes,transformers,transistors,etc...)you use those right?
yes, it's a little embarrasing to dumpster dive
yes it's a b1tch to haul an organ or gut it on the side of the road...
yes it's worth it!

[Mark Hammer]

I think somebody mentioned few weeks ago some kind of rotating system made of lightweight polystyrene foam, that spins around stationary speaker. Because of small mass you can manage with smaller motor. Last time I visited a local flea market there was some cheap old home organs, and under the hood was 8 inch speaker and "leslie" thing...

if you see an organ on the side of the road  rip out the rotating speaker!
its free...
it's a rotating speaker with (usually)2 ac motors!
sure, you don't see them every day... but when you DO they are usually there for a while...(hard to fit in a garbage truck!)
just a rotating wood(old) or styrofoam(new) cheeze wheel looking thing in a wood frame with a speaker.
the "leslie thing" in some home organs IS a leslie(not LESLE brand but a rotating speaker..)

That's what I had 25 years ago, and recently reacquired.  Apparently the stationary speaker and rotating "cheese wheel" baffle is the system the Fender Vibratone (an SRV fave) used.  Mine came from a Kawai organ but has labels on it that clearly identify it as a Leslie product.  They work wonderfully well.  Although QZ notes the presence of a tube amp, such speakers continued to be incorporated in home console organs long after manufacturers considered it critical or prudent to include tube amps in their organs.  Doesn't mean there CAN'T be a tube amp pushing it, though.  I drive mine with my old Princeton.

I haven't looked deeply enough into it to confirm or refute, but my sense is that the depth of the effect is strongly related to the radius of travel.  For several reasons.  First off, to cover a larger circumference (the result of a longer radius) yet still provide the same modulation rate (in rotations per second), the baffle has to move at a faster speed.  The fairly slow movement velocity needed to get a baffle with, say, a 6" radius, to move in a complete circle once every second, is much less than the velocity needed to get a 15" radius baffle to cover its much greater circumference in the same amount of time.  Since the speed of sound remains constant, and the Leslie sound is partly a product of the doppler interference produced as the sound source moves, the quality of the doppler effect will be greater as the velocity of the sound source increases.  One need only think about the doppler effect produced by moving motorcycles, vehicles, and aircraft.  Slow any of them down, and the effect is reduced.

Second, while jet planes and trucks pass you once and don't return, rotating speakers....rotate.  Part of the Leslie sound is the throb, and the throb is a result of a sound source not only moving, but moving away from you and coming back toward you.  With each rotation, there is a simultaneous modulation of volume (quieter as it points away form you), and frequency content (duller as it points away from you).  Of course you can make even the best-designed Leslie not do that if you sit righ on top of it where you can't hear such variations well (i.e., where what you hear is more constant because it is less affected by baffle direction).  But all things being equal, if you are standing a modest/rasonable distance away from one, the effect is perceptibly richer if the baffle or rotor (or whatever is the final exit point for the sound before being launched into the world) has a wider radius up to some maximum.  I leave it to Ton/Puretube to snap back with a Don Leslie patent from 1930-something illustrating the optimal radius.

In any event, while I encourage folks to let their imaginations run wild and come up with other methods of producing this delightful category of effects, I also encourage them to keep in mind the relationship between radius, velocity needed to achieve the desired modulation rate (i.e., physically mimic an LFO), and effect intensity and quality, as they turn those dreams into quirky Rube Goldberg ( http://www.rubegoldberg.com/ ) realities.

[Quackzed]

yeah, i plug mine into my twin, tho i'm carefull how loud i crank the amp, as i killed the original speaker that was in it
never DID use the tube amp section i found...
definately a big wow factor when i let my friends play through it!!
btw, dont try to hook up a variac (ac voltage controll) to it, you'll burn out the motors!! (there may be a way to do speed controll but i haven't found it...
the 2 motors are for slow and fast small/big motor respectively,
AND were talking 120v ac here so make sure you KNOW what your doing if your gonna wire up the motors yourself... i used a 3 way center off light switch for high/off/low speed... works great!
some of em are mounted sideways( a la bike wheel) and you may need to futz with the motor coupling wheel (mine has a little nut that can be adjusted for the small motor(chorale) to make contact when it's swiched on) as the small motor kinda gets pulled down when you turn it on...it's a little finiky and it wont allow the big motor to get up to speed if its always touching the coupling wheel(delicate balance)...
adjusted it and now it has no trouble
really cool full sound, nothing like it really!
i've heard good simulations and from a recording playback perspective there may be some that are indistinguishable, but theres nothing like being in the same room with one of these things!!!

[Mark Hammer]

A lot of folks THINK they know what it's like to play with one of these, simply from their experiences with phasers, choruses and flangers. Nuh-unh.  Not the same.  My buddy Tim, who produces an excellent CE-1 clone that gets rave reviews from people (check the March Guitar Player) came over a couple of months back and had never played through a rotating speaker until then.  I told him that every player deserved to play through one at least once before they died.  It was hard tearing him away from it.

I have only tried one of the various DSP rotary emulator stompboxes out there, so I can't say anything about best and worst, but I have to say it compared VERY favourable in an A/B test with my cheese wheel box.  As myself and others have concluded here, though, you absolutely need a stereo (two amp) setup to appreciate these things, regardless of who makes them.

Okay, lets get back to mini-amp tetherball, already in progress...

[AdamB]

couldn't you make the same effect with 2 amps (1 on each stereo left/right channel) and a foot pedal (similar to a wah enclosure) that changes the ratio of the mono signal between each channel (rocker pedal in the middle = left and right, all the way down = right, all the way up = left)? Then you just move your foot up and down to make the throbbing leslie sound. Needs 2 amps tho. Hrm...

EDIT: No, that wouldn't work, as there is a volume drop/increase to deal with too, isnt there. Hrm.

[Mark Hammer]

No, its different than that.  Remember that what we're dealing with is an effect of a moving sound source.  In other words, the place where the sound originated barely a moment ago USED to be there, but now its over here, and over here, and now over here.  The sound wave created barely a few milliseconds ago is still pushing its way through space, and before having travelled very far, the very thing that MADE that sound has physically caught up with it (or close to).  One of the reasons for the strong suggestion to use two amps is that since the doppler effect is a function of the sound source "catching up" to a traveling wave, the place where the catching up occurs will keep changing, such that what each ear hears will not only be different in terms of volume, but in frequency content as well.

That is not to say that panning between two amps isn't a potentially luscious effect in itself (and we certainly don't pay enough collective lip service to panning here).  But it isn't the same thing as what a moving sound source does.  In the case of panning as you describe, the relative volume between two fixed sources changes and creates the impression that the sound source is moving, but in truth it isn't and that makes for a very different outcome.

make sense?

[puretube]

I leave it to Ton/Puretube to snap back with a Don Leslie patent from 1930-something illustrating the optimal radius. 

>no, I won`t do that<... 

Sir Leslies great efforts (at least, some) can be found here;

for creating (a virtual) radius, I prefer this:



which isn`t limited to circular motions,
but can go elliptic, into an "8" shape, and reverse its direction on the fly
by evolving into a perceived third dimension
during the transition...

http://www.pure-tube-technology.com/Furth/wahcast682.jpg

and, err, yes, it`s pure tube
(patent applied for  )

[Quackzed]

that... 
whasda
erm.....


OH
MY
GOD!!!! 
THAT THING is
....AAWWWEEESSSOOOOMMMMEEEEEE!!!!!!!!!

um...puretube? ah...your freaking me out a little bit...    LOL

[puretube]

ooops, forgot the rear-view:

[Quackzed]

  o.k ALOT!!!

?Does the eff bee eye know you've got that thing?!?!
It looks like it could warp me back to 1969!!!
I can tell you've spent some time in "the other place."


I gotta think bigger...

[John Lyons]

I've done the microphone thing in the studio.
Swinging a mic on cable, about a 5 foot orbit clockwise (parallel to the ground) , another mic on about a 15 foot orbit counter clock wise. Takes two people. Pan one left, one right. Yowza!

[Quackzed]

i wonder what a rotating mic would sound like if it was spinning at 7000 rpm's or fast enough to "blur" the perseption of motion.  like tv... would it just sound like an omnidirectional mic? ?    maybee if its mic capsule was at the axis of rotation, but what if it was a foot away? you could use it like sonar...get a centralized 3d soundscape with 1 mic.    what about the doppler effect? since the mic would be "practically" or perceptually always moving away from you and "always" moving toward you would it generate a "blur" of tone slightly below and above?     
     if anyone has a wireless mic and a dremel, it might be an interesting experiment! or a good way to destroy your wireless mic! 
half-baked?

[Quackzed]

at least with battery powered amps you dont have to mess with brushes etc... for the spinning speaker contacts... you just spin the whole thing... er.. you still have to plug your guitar in tho...   have a "leslie" type rotating cheeze wheel speaker i gutted an organ for... very cool sound...now go put your battery amp on your turntable and you'll want to build it!

[A.S.P.]

plug the guitar via a "wireless"...

[Nasse]

Good idea. What the hell, if you can spin a mic in the end of the cable, you can do it for 386 amp and a small speaker. Till the cable goes bad...