Veneering the Cambridge

August, 2006


While I was doing the initial mod work on the amp, I was getting good advice from the always knowledgeable and ever-resourceful Richard Carter. I mentioned to him that I was shimming the front baffle board using leftover mahogany veneer, and he (I think) half-jokingly suggested that I could try veneering the entire cabinet. At the time, I was preoccupied with whether or not the power amp upgrade and speaker swap would 1. hold up in a full-volume band rehearsal setting and 2. be a sustainable modification (I occasionally get nightmares about the joke we had in our electrical engineering classes: "the secret to electronics is the magic smoke: if your circuit releases it, it's over"). But a few weeks on, I started taking the idea a bit more seriously. The amp was acquired second-hand, and the tolex in some places had seen better days, though it wasn't anything that would show up in a photo. That, and I'd seen pictures of the Rose-Morris era "Collector" edition AC30s from the early 1990s with their solid mahogany cabinets, and subsequently drooled over them. So I figured I'd give it a shot. Mahogany veneer over MDF and particleboard isn't the same as solid mahogany, but it sure as hell would be a fun thing to try.




Vox amp afficionados will joke that the black tolex on their amps will come off/rip/etc. if you so much as look at them sideways. While I can certainly attest to the verity of this statement, a low-heat iron also works wonders in getting the stuff loosened for easier removal :)



Here, a paint scraper came in quite handy to remove the glue residue that was left after I'd ripped all of the tolex off.



Here, I am using just about every clamp I own to glue on a particularly thin and finicky strip of veneer.





I had originally planned on using some of this wonderfully figured "Bennett" brand mahogany veneer that I bought at the local Big Dog home improvement type store, but it turned out to be far too brittle to wrap around the corners. So... to Lee Valley I went. The repair guys at the 12th Fret in Toronto swear by this place, and a far more experienced woodworking friend of mine here in Québec City uses their internet ordering fairly often. Their veneer is less figured, and not as rich in colour, but it's been treated to make it much more flexible and easier to work with. For the eight actual amp cabinet corners, I built them up to a 90 degree angle, and then filled them with hot-melt glue. Hopefully, in addition to the brass corners (also purchased from Lee Valley) will give it both strength and shock absorption for any dings that do happen.





The finish I used was this Minwax stuff they call "Tung Oil Finish," which is evidently not really Tung Oil, but rather a mixture of tung oil and varnish, thinned with lovely mineral spirits. It does give a nice hand-rubbed texture, though, and brings out the grain of the wood rather well. In total, I put on about 7-8 coats of the stuff.









So, there you have it, a highly-personalised little amp that not only looks pretty neat, but sounds great as well. I don't think there have been any qualitative studies done on the tonal improvement one acquires by going from tolex to mahogany veneer, but I certainly hope the sense of satisfaction I get just from looking at the amp will inspire me to play better!


Update: Sept. 17, 2006

So I finally broke down and bought a length of the brown diamond grillcloth from Northcoast Music, and took the opportunity to enlarge the speaker baffle hole about an inch in diameter:



I think this completes the "boutique amp" look quite nicely now!