This is the second Champ I've retro-fitted for a 10" speaker and it's a stock silverface model built in 1980. The Champ cab is typically made out of 3/4" pine that's Tolex covered. The speaker baffle board is 1/2" flakeboard that's set into channels in the cab's sides and bottom - fastened with glue, and staples that were shot in from the outside before the cab was covered.

For the first retro-fit I removed the flakeboard baffle, cleaned out the baffle channels and set plywood cleats into the channels to hold the baffle board, which was also re-covered with new speaker cloth. This second speaker retro-fit is every bit as good as the first, only it's faster and much easier.

First, I pulled the chassis, removed the speaker grille (it's Velcro'ed on), and then removed the flakeboard baffle - you will need to literally crumble out the baffle with a hammer, it's not strong at all. You don't need to remove any pieces of the flakeboard, or the staples, that remain in the channels - just get them at least flush to the sides of the cab.

When the baffle has been removed, and the baffle channels are cleaned out and/or the remaining flakeboard is flush (or below) the sides of the cab, lay the cab face down over a piece of 1/2" 5-ply birch plywood and scribe a pencil mark on the ply of the panel sides and bottom - for the top, just draw a line to connect the the two side lines. You could also just trace around the speaker grille. Put a mark on the plywood to note the inside top of the new new speaker baffle. Cut out the new speaker baffle using a sabre saw.

Lay the 10" speaker on the inside face of the baffle board, all the way to the right - the speaker edges should be within 1/8" of the top, the bottom and the right side of the inside face of the baffle. Draw the outline of the speaker on the plywood. Draw a circle 1/2" to 5/8" INSIDE the speaker outline circle - cut out this inner circle with a sabre saw.

Center the speaker over the speaker baffle hole. Use 3/4" square hardwood (I used red oak) to make the baffle cleats. There'll be one long full length cleat on the left side, two short cleats on the right side, one medium length cleat on the left bottom and one short cleat on the right bottom.

Pre-drill holes into the baffle cleats and screw them into the sides of the baffle, with the front edge of each cleat right on the INSIDE edge of the channel. Use 1-1/4" dry wall screws (with a small washer to limit and insure that screw won't push through the cab wood), and also put a small bead of carpenter's glue on the cleat before screwing down.

After the cleats are srewed in, place the baffle on them and mark where you'd like to put screws through the baffle. It's not rocket science - just put the screws where you think they'd be best located. Pre-drill the baffle cleat screw holes with a 3/16" hole (larger than then screw diameter). After the baffle screw holes are drilled, place the baffle back on the cleats and use a 1/16" drill bit to make pilot holes into the hardwood cleats. Screw the baffle to the cleats with 1-1/4" dry wall screws. Note where I've drilled for the four speaker screws (I reused the machine screws from the original baffle).

There's plenty of room to remove/install all tubes without the speaker interfering. The speaker is a ceramic Weber 10F150T and it's a perfect match for a Champ chassis.

I flipped over the grille so that the speaker cone wouldn't be partially hidden by the Fender logo. A kinda funky looking Champ with that "misplaced" lower right logo, but looks are always second to me when compared with getting sweet sonics and improved headroom, bass, clarity and volume.