Tube Amp Archive

I got a hold of a 12" Fender tone ring, and I'm going to build a cabinet for it.

From pictures I see online I can roughly proportion the cabinet size etc but if anyone has built one I'd be interested in sizes.

John

Here's a PDF
I think that it's for a 15"
LeeMo

Yes, that's one of the pictures I'm using as reference.

http://rawoods.com/?page_id=173

This is a 12" Trying to figure the diameter of vent hole, and overall size of cabinet. The original cabs were probably 5/8 material, so front of ring flush to surface gives me standoff thickness and back vent size for consistant vent width.

John

Cantplay wrote:I got a hold of a 12" Fender tone ring, and I'm going to build a cabinet for it.

This is funny, it's like finding a faucet and deciding to build a house around it

12" cab size is 21"x30"x11.5", about 2" narrower than the sealed cab. 15" cab was 24.5"x36"x11.5". Came as one of the options for the blonde showman in the early 60's and used a JBL D-120F driver.

-ER

IT'S Called a Helmholz resonator. Its designed to sort of tune the enclosure to the D120 or in the case of Single Showman amps, a D130F.
JBL speakers have always been very sensitive to proper box tuning.

Cantplay, I have detailed plans for the 15", but not the 12". Would the 2 front panels spacing be the same?
I want to build a 15" tone ring cab some day, and have the ring dimensions at a local welder with a computer controlled plasma cutter, but so far, he hasn't had the time.

CAREFUL ON THAT WELDING! You can more economically build welded rings for 10" 12" and 15" concentrically cut from sheet metal with a flat band welded between the two rings. Your welder had better know his stuff or the rings will come out warped from the heat of welding or cutting & you can tweak the speaker frame trying to use them. I make a batch once or twice per year. The program is in the CNC plasma cutter, and a long strip of steel is welded between the two rings. The rings have to be clamped on a welding jig or they will warp. My last batch sold out in 4 days. The best way to make these would be pressed, stamped & die cut, like the originals, but you will need a tool & die shop to make the stamping & cutting dies , a press former & a punch press. I did not get a clear answer from my tool & die person whether or not you can do concentric rings to save materials. As for welding: By placing a 10" in the center of a 12 and the 12 inside a 15" you save a lot of sheet metal. Heat from plasma cutting & welding warps the metal. 3/4" plywood is not quite 3/4" thick. The soft wood stuff can be + or - 1/32", usually it is thinner. MDF is the same, poor tolerances. I took my dimensions off a brown Showman 1x15, & from some 2x12 cab that may have come from who knows what. It is an 8 ohm factory Fender 2x12 cab. It came with a 4 ohm Bassman, & I put 8 ohm Marshall UK Celestion Wolverines in it to make it a 4 ohm cab. The JBLs will go into something else. Maybe a 4x12 cab loaded with JBLs, & or JBL & Fane. I found tack welding the rings at 12 o'clock, 6 o'clock, 3 o'clock, & 9 o'clock, then tack between those, while the work is clamped flat. That worked best, then keep adding more tacks, & more tack welds, then fill the gaps like tightening a head on an engine. Cross tack or fill at 180 degree across, rotate 90 degrees repeat you 180 degrees across. Do not weld all the way around in one long bead, it will deform the ring) Once you do get a good bead, grind it smooth, & add some paint & they'll look great. You can leave the weld beads if you like, as long as they are not in the way. Your welder guy will appreciate making 3 rings from the same sized piece of metal. The flange is just a strip of sheet metal cut to length. 10" tone rings sound pretty darn good too!

I like paragraphs.

Mojotone still has a few rings left if anyone wants one.

John

Nothing but a variation on a bass reflex cab, although I haven't seen it executed this way before.

Various designs have been made , based on the original design of the Jensen Ultraflex. A subset with a limited selection of T/S parameters are known as Onken cabs....

https://www.google.no/search?q=jensen+u ... B362%3B393