Wondering how different an amp might sound in an all wood cabinet

Rocker

Take, for example, a Marshall valve amp head. It is built in a metal chassis contained in a wood sleeve. Suppose instead of a metal chassis, a wooden chassis were used. Has anyone ever tried to build such an amplifier and how different did it sound compared to a conventional metal chassis’s amplifier?

Just thinking out loud. Thanks. 

DartmoorHedgehog

I don't see how it would make any difference if you're talking about a head. Perhaps a little bit more prone to interference because of the lack of shielding from the metal chassis.

Funkfingers

Metal amp chassis is the preferred material because it is durable, workable, copes with heat, may provide screening and ALWAYS provides a reliable path to ground.

A wooden amp chassis is not impossible to make but the wisdom is questionable. Tapped threads would wear more quickly, air circulation holes would need drilling because wood is a pretty good heat insulator … until the moment when it scorches and, possibly, catches fire.

Speaking of which, without a metal chassis to complete the ground path, every relevant component would need its own individual ground connection. Result, a veritable rat's nest of cable runs, all with the potential to be a fire hazard.

stickyfiddle

The cabinet is the important bit here. Those are already made of wood, and different cabs definitely sound different. But a different material for the head wouldn't make any difference - that's getting into audio snake oil territory

EricTheWeary

I remember something in Guitar Player many years ago about ‘tonewood’ cabinets and the difference they made. Fair to say that they didn’t catch on. But I suspect that cabinet design is massively more important than the type of wood. 

WezV

On a head, it won't sound different at all.  It will be massively less reliable than a metal chassis.

If you want the look of an all wood amp head, you could veneer the face and back plate of the chassis.

Rocker

Part of the reason I asked the question is because a friend of mine has built a DAC on a sheet of plywood.  He is trying different modules with the ultimate aim of getting the combination that sounds best and mounting them in a cabinet [probably metal].  At the moment, all the modules and PSU are 'standing' in fresh air on the top of the board and the sound is unbelievably good, and very significantly better than any commercially available DAC I have heard.  It would be a pity if even a small proportion of his good work is lost due to the metal cabinet being brought into the equation.  The only way to know is to fit the modules in a metal cabinet!

I have a long term ambition to build another guitar amp from scratch or more likely from a kit.  In the past thirty years I built two guitar combo valve amps and one stereo hi-fi valve amp.  My eyesight is not what it used to be but I think that problem/issue could be overcome by using a head mounted magnifier of some sort.  Part of me wants to make this amplifier 'different' from commercially available amps or kits so I pondered on the use of a timber chassis.

Anyway no decision one way or the other will be made before next Spring......

ICBM

It would sound different, even as a head. The chassis material makes a difference if it's aluminium or steel, so it certainly would if you used wood and (presumably, since you need it) foil screening and ground busbars.

If you just want the look of an all-wood head, Trainwreck did that...



... but used a conventional metal chassis.

PeteC

If you do decide to try mounting components for a valve amp on a wooden/other type of circuit board just be aware ( you may already be ) that at HV not all materials are sufficient insulators.

I once built a 5EA5 Pro Tweed clone on "phenolic" circuit board only to find out later on that the board I'd used was very slightly conductive. 

I've also built plenty of hifi and guitar circuits on unscreened breadboards and in the main they were great - except for high gain preamp circuits where the lack of screening was a big show stopper - especially under fluorescent lighting. 
The best SE hifi amp I had was a breadboarded Shishido/Loftin White with ECC83s and output tubes from Russian fighter jet transmitters, 6C4C's I think it was ( best use for them clearly ! ) 

Plus - although breadboarded amps are great fun - they're not very portable(!) and you run the risk of electrocution with valve circuits if you forget what you're doing for a second.....