Almost to Swirly World!!

Flames1950 · Post by **Flames1950** » Sun Dec 12, 2004 9:40 am

Here's some progress pics on my "poor-man's Vibratone/Leslie":

The guts are a 1965 rotating speaker from a Thomas Organ (apparently not much of an organ but the speaker assembly is fine!!) I built the cab right around the assembly, which worked nicely for extra stability since I didn't have a way to do finger joints in the corners. I simply screwed the sides to the existing assembly and added cleats in the corner joints. Some eBay tolex and grille cloth later and all that's left is the switching wiring. The speaker is the Weber 10" Chicago, rated at 60 or 80 watts depending on where on Weber's site you're looking.

Almost there, I can't wait to fire it up!! But it needs casters still, it weighs in at a ton to a ton-and-a-half!!

thunder970 · Post by **thunder970** » Wed Dec 29, 2004 8:32 am

I thought I saw a keyboard player that had one that the speaker would spin. I don't think I was that drunk, or was I?

P.S. he said it was one of Aaron Neville brothers cabs from way back. It was a stained homemade looking box.

Flames1950 · Post by **Flames1950** » Wed Dec 29, 2004 10:25 am

There are models where the speaker itself will spin. The real organ Leslies (models 122/147 [?] being the most common) have a rotating drum baffle (the Vibratone and my homebrew are done this way) in front of the lower frequency speaker, and the horn for the highs actually spins around (no horn in Vibratones.)
I saw an assembly on eBay with 6x9 speakers mounted in the drum itself so that the speakers were spinning. The slip ring/contact assembly to make that kind of thing work is a pain in the ass.
BTW I finished up the wiring to this thing a couple of weeks ago, it's way fun and mucho cooler than my H & K Tube Rotosphere simulator, sounds killer!!

Billy Batz · Post by **Billy Batz** » Wed Dec 29, 2004 11:24 pm

I thought it was a Leslie has the drum and a Vibrotone and 145 spin the whole speaker? Maybe Im wrong.

Flames1950 · Post by **Flames1950** » Thu Dec 30, 2004 12:05 am

The Vibratone/Leslie 16/Leslie 18 for guitar all use a drum in front of a speaker.
Many organs did as well (obviously, mine are old organ guts) but there are examples of rotating the speaker as well. The upper horns on two-way Leslies rotated.
Here's a link to all sorts of info on the Vibratone/ Leslie 16 & 18:
http://mywebpages.comcast.net/vrbass/vibratone/
Also has a very helpful link to a Vibratone manual, shows how to adjust the motors, etc.
Seriously, this thing was pretty easy to build and only about half the cost of buying the Leslie 16, less than half of the Vibratone's bill. Get on eBay and scrounge for old organ guts (just don't get the 8 inch speaker by mistake, there's loads of them out there.)

Billy Batz · Post by **Billy Batz** » Thu Dec 30, 2004 10:42 am

Can you show a pic of the front of the cab without the grill? With the drum? Please please please please please please please please please please please please.......?

Flames1950 · Post by **Flames1950** » Thu Dec 30, 2004 3:12 pm

Yeah, but it may be pretty late tonight or tomorrow by the time I get it done, my wife has class tonight so I've got the baby all night.

Flames1950 · Post by **Flames1950** » Thu Dec 30, 2004 11:34 pm

Billy, here's the pic of the inside of the cab from the front:

Newer Leslies and the Vibratone used a styrofoam rotor, but mine was old enough it was made of plywood. I'd guess the styrofoam would be lighter and better balanced (my plywood drum uses bolts and buts to balance it, and surprisingly well I might add.)

Necrovore · Post by **Necrovore** » Fri Dec 31, 2004 3:07 am

Sorry to butt in but I understand what this speaker box sounds like just how exactly does it work? probably easier if you can point me to a website where I can look into it more, thanks.

Flames1950 · Post by **Flames1950** » Fri Dec 31, 2004 8:27 am

The website I mentioned a few posts above is about the only one I know of, but I haven't searched very hard either.
Instead of directing the speaker's sound out the front of the cabinet, this Leslie/Vibratone style cab directs it out the sides -- the speaker fires into the rotating baffle, which has a scoop (which you can't see from the pics) to direct the sound sideways. Then, since it rotates as well, the sound gets directed to the sides and top with some sound bouncing around inside the cab finding its way out at odd times. This creates a Doppler Effect of changing pitch and volume. (You know how police sirens or jet airplanes sound like they get higher in pitch and volume as they get closer, and then drop in pitch and volume as they get further away? That's the Doppler Effect, and since it's controlled in the cabinet and directed around the side and top vents, you get that fab swirly sound that chorus pedals and simulators just don't get as well.)
The only downside is that a 1x10 speaker with the sound fired out the sides doesn't quite keep up with a raging Marshall and 4x12. I haven't run them together yet, but I think I'll hear just enough Vibratone to add swirl to the sound, without being an overpowering effect. SRV usually ran his Vibratone this way, as an additional sound mixed with other amps.

Billy Batz · Post by **Billy Batz** » Fri Dec 31, 2004 1:10 pm

Thanks Flames. I was always curious how the Leslies worked. Im still a bit unsure of whats going on in there. Whats changing as that disc rotates? It looks like its still blocking the speaker the same amount the whole time.

Flames1950 · Post by **Flames1950** » Fri Dec 31, 2004 3:06 pm

The disc is actually about eight inches thick. The center of the back of the disc has holes cut in it for the speaker's sound, and a metal bar supports the bearing for the back of the drum. The holes direct the sound into a scoop that goes from the speaker to the outside of the drum so that the sound shoots out the scoop in different directions as the drum rotates.
At some point I still have to take the back off and add some sealant and insulation to eliminate some vibrations. I'll try to remember to pull the speaker and take a pic of the back side of the drum. But it may be a while, I'm not in a big hurry on it.

Billy Batz · Post by **Billy Batz** » Fri Dec 31, 2004 4:59 pm

I totally see it now. It is pretty deep.