Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: J3ona1 on February 04, 2023, 03:08:46 pm
-
Hi everyone,
Do you know where i can get detailed measurements/plans to build my own vibrochamp head cabinet? I am using the mojotone chassis.
-
Do you know where i can get detailed measurements/plans to build my own vibrochamp head cabinet?
No. Funnily enough there are good CAD drawings of Fender guitar bodies easily available, but I have not seen detailed plans for cabinets.
Best thing to do is to get your chassis in hand, take careful measurements, and design your own.
You can get a pretty good idea for what is needed just by looking at the Monotone cabs, as well as some of the cabs shown on eBay.
When you do put your design on paper, make sure you take into account the thickness of things like Tolex, fittings, etc, as well as variations in the chassis. I won't say how I know this . . .
-
Attached are a couple of pics that you might find helpful.
The front panel of the blackface amps is recessed in about 1/4" with deviations for tolex thickness & the faceplate.
The back of the chassis is set in 1-1/4" from the edge of the cabinet. The vertical cleat that the back panels screw to are set in approx 5/16", so that the cover is flush with the edge when installed.
Take note of the corner rounding: 3/8 radius on the outside edges, just barely rounded (probably by hand) on the inside edges.
So, as acheld suggests, if you take your chassis, add about 1/8"-3/16" for some wiggle room to the length & add these two measurements to the width, that will give you you inside dimensions for the cabinet.
As far as height, that will be designer's choice, maybe borrow an overall outside height from a Bassman, Bandmaster, etc. & see how that looks proportionally.
I will also add that the head cabinets have a vertical front grille, where as the combos have the grille slightly angled. Straight up & down will make it easier to build.
I believe that the facepanel angle is 25° which might help with your layout.
-
I have the attached plans in my files. Not champ, but maybe helpful as it has the angles.
I built a Vibro Champ head - I had a combo cabinet that I took measurements from. That head is not here, but I will visit it in about a week and can take some measurements.
Are you using finger joints/dovetails? If so, a tip from experience; mill out all your pieces as 900 rectangle pieces first; cut the fingers and check the fit; then cut the angles. That way when you cut your finger joints, you have all square edges to work from.
-
Thank ypu all sooooooo much!!!!!!
-
Although original Fender Champs didn't use metal corners on the bottom 4 corners if you plan on using them then use a 1/2" radius round-over router bit. All of my original Champs/VC look like they have 1/2 radius on the outside edges (except top front).
-
Im going to use finger joints. Thanks!!!!
I have the attached plans in my files. Not champ, but maybe helpful as it has the angles.
I built a Vibro Champ head - I had a combo cabinet that I took measurements from. That head is not here, but I will visit it in about a week and can take some measurements.
Are you using finger joints/dovetails? If so, a tip from experience; mill out all your pieces as 900 rectangle pieces first; cut the fingers and check the fit; then cut the angles. That way when you cut your finger joints, you have all square edges to work from.
-
add about 1/8"-3/16" for some wiggle room
3/16 is good, or even more . . .
You can always add material under the Tolex as padding if needed.
If you're going on the road with the amp, finger joints or dovetail is definitely the way to go.
But, if it's going to be a stay at home amp, I use baltic birch plywood with butt joints reinforced by pocket screws. Works well, and I have not had one fail yet even with moderate usage (which was not the intended use). This technique saves a lot of time and dust.
-
Another good way to assemble the cabinet panels is with glued in hardwood dowels which make a very strong joint. Easy to do as well. They can be blind or not. If the cabinet is covered then it doesn't matter.
-
I built a Vibro Champ head - I had a combo cabinet that I took measurements from. That head is not here, but I will visit it in about a week and can take some measurements.
Attached are simple dimensions from the one I built.
The chassis is an actual Fender Silverface chassis. You will want to adjust for any minor differences of course.
I allowed about 3/16" for clearance of the tolex - you do not want to force that chassis into too tight a space.