1974 Plans and Wood

[rmroza]

Ok, I got the 1974 Style Cabinet Plans r1.2 free online from MODULUS. Are these the best plans/drawing?? I know it references some done by Graydon (GDS). The instructions sure seem pretty comprehensive thou, but I think the dimensions were a few millimeters different from the original when I checked the Marshall site versus the drawings. Soo, the first question is what plan(s) to use?

The second question, is in this file and drawings, it references to use "void free" wood! I'd like to know what this is and if I can get it locally at say Lowe's that has Oak/Maple/Birch 4x8x3/4" ply for about $50 a sheet. Where can I get solid Oak/Maple/Birch I want this thing to be like furniture and like not much you can buy or commercially. Thank you.

Please let me know. I will start this as my project starting this weekend!

Robb

[nyazzip]

"void free" just means high grade plywood. if you look at the edge of low quality plywood, you can see gaps and dropouts and holes, ie "voids". if you are making a speaker box out of wood that has voids in it, the theory is that the voids will cause undesireable and unpredictable resonances at certain frequencies. the plywood manufacturers use the two nicest laminate sheets for the outside surfaces, and use the garbage wood with lots of knot holes for the inner laminations that no one will see...
home depot and menards sell solid plank hardwoods in widths of up to 12 inches; here they have poplar and aspen(i know, not really a hardwood), maple, and oak. be aware that your speaker box may not sound great(harsh/midrangey/bright) if you go with solid wood, as solid wood is generally resonant and carries a "tone" when you rap it with your knuckles. thick plywood just goes "thud"; it is the most common acoustically inert building material and it is relatively cheap, so that is why it is used for speaker boxes. i sure hate transporting and cutting down giant sheets though
i have made a couple of guitar speaker boxes out of pine and cedar plank, and i can attest that it really does sound different. i would say the more distortion you plan on playing with, the more "acoustically dead" of a speaker box you will want. and that wraps up my 2 cents

[zaphod_phil]

I got the 1974 Style Cabinet Plans r1.2 free online from MODULUS. Are these the best plans/drawing?? I know it references some done by Graydon (GDS). The instructions sure seem pretty comprehensive thou, but I think the dimensions were a few millimeters different from the original when I checked the Marshall site versus the drawings. Soo, the first question is what plan(s) to use?

If those plans really came from "Mr 18W" Graydon Stuckey, then they will be good. Graydon was one of the main guys who started this Marshall 18W revival, which eventually even provoked Marshall to come up with their own RI version. There were effectively two generations of the original Marshall 18W amps. The earliest "first born" production batch had some small constructional differences from the later production - see the pictures of Ian's and Colin's original amps in the Gallery section. And it wouldn't surprise me if the RI version is also slightly different again.

[rmroza]

Yes, the design is based on Graydon's. I'd like it made better than Marshall and commercial with hardwood such as the first couple of combo's here: http://mrdwab.com/john/amplifiers.html

I will probably mount the amp toward the front rather than rear and cut a whole and put a metal mesh in the fron so you can "see" the tubes.

Man, I need to know how to get this wood. I'm worried if I go to Lowe's and get some Birch veneer play like I did already do an extension cabinet that looks and sounds fabulous, that when I do the edges, you're gonna see ply which really turns me off instead of a solid piece. I want this to be hard wood and durable, but like you said, will need to take note of type and acoustical value.

Here's the link: http://mrdwab.com/john/amplifiers.html

If anyone could help me identify how to go about doing this, that would be great.

thanks in advance.

robb

[Rocknhorse1]

Yes, the design is based on Graydon's. I'd like it made better than Marshall and commercial with hardwood such as the first couple of combo's here: http://mrdwab.com/john/amplifiers.html

I will probably mount the amp toward the front rather than rear and cut a whole and put a metal mesh in the fron so you can "see" the tubes.

Man, I need to know how to get this wood. I'm worried if I go to Lowe's and get some Birch veneer play like I did already do an extension cabinet that looks and sounds fabulous, that when I do the edges, you're gonna see ply which really turns me off instead of a solid piece. I want this to be hard wood and durable, but like you said, will need to take note of type and acoustical value.

Here's the link: http://mrdwab.com/john/amplifiers.html

If anyone could help me identify how to go about doing this, that would be great.

thanks in advance.

robb

Baltic Birch plywood is void free and available at most lumber yards.
They also have an iron on edge material cabinet makers use for kitchen cabs. This comes in maple oak or whatever you want. Depending on where you go, and what they stock, you may have to order what you need. The edge material is very easy to use and looks good. They also make a special plane to plane the excess edge material off, and make a nice flush edge. These are fairly cheap and made out of plastic. The sales guy, or someone in their cabinet department should be able to help you. Remember BALTIC BIRCH.

[guitarmike2107]

The plans where taken from Graydons drawing and other coments made in the download section. its all there you just need to decifer it. the modulus drawings were done to just make it easier for those who dont have cad programs... compare first if you want and make your mind up from there.

BTW Its only so comprehensive because I had time and had already modelled the cabinet in 3d.

void free is pretty important , most hardware shops sell construction grade plywood.. this stuff is cheap but not woth the hassle when your cab that you spend hours building and covering has an annoying buzz when you hit a certain note...

Good luck with your build

Mike

[CurtissRobin]

Man, I need to know how to get this wood. I'm worried if I go to Lowe's and get some Birch veneer play like I did already do an extension cabinet that looks and sounds fabulous, that when I do the edges, you're gonna see ply which really turns me off instead of a solid piece. I want this to be hard wood and durable, but like you said, will need to take note of type and acoustical value.

First of all, birch veneer plywood is not at all the same as Baltic birch plywood. If you were to use the recommended Baltic birch plywood you'd still see plies on the edges because it is plywood. This is only undesirable if you plan to leave the cab uncovered and you don't like the appearance of plies. (I've seen some mighty fine furniture built with exposed plywood edges.) Baltic birch plywood is a much higher grade of plywood than the stuff you buy at the ubiquitous "home centers." Baltic birch ply uses 9, 11, 13, or 15 plies, depending on the sheet thickness while the home center stuff never goes beyond 5 plies. Even the hardwood veneer stuff they sell is second rate compared to genuine Baltic birch plywood because the interior plies are rarely patched where knots occur naturally in the wood layers. That leaves internal voids (empty places). Out of sight, out of mind is OK for the uses those products generally get but for music it often is not OK.

Solid hardwod is wonderful stuff with about the same resonant characteristics as plywood. It's too stiff to contribute anything meaningful to the sound of an amp unless you use extremely thin boards. It looks great, though, when well fitted and well finished. If you're after the appearance of fine wood joinery and finish hardwood is the best material. If you're looking for a solid wood to contribute to your sound you'll want to use pine.

A really good substitute for Baltic birch plywood is marine grade plywood. Marine grade is boatbuilding plywood and the industry standard requires that all voids be filled which is done during manufacturing by punching out the knotty area of a layer and embedding patches of the same wood. The patching is done before the plies are laminated. Wait'll you see the price, though. Mighty few lumber yards stock it and they are usually merciless in charging you for it. You'll really want to comparison shop for this.

HTH
KennyO

[rmroza]

"Solid hardwod is wonderful stuff with about the same resonant characteristics as plywood. It's too stiff to contribute anything meaningful to the sound of an amp unless you use extremely thin boards. It looks great, though, when well fitted and well finished. If you're after the appearance of fine wood joinery and finish hardwood is the best material. If you're looking for a solid wood to contribute to your sound you'll want to use pine. "

Yeah, I could go traditional and Baltic Birch or whatnot, but you know, I'm going thru all of this work to build a "boutique"-style ampo with my bare hands. I don't want to chince out. Soo, yeah, I'd love to just build up a solid hardwood cabinet (NO laminate or ply).

Pondreing that thought...where can I get solid hardwood from??

Your helpis greatly appreciated as always!

P.S. - Just for giggles, I'm assuming this is what would be good for the Baltic Birch - http://www.woodnshop.com/Hardwood/Balti ... lywood.htm ??

Robb

[nyazzip]

Solid hardwod is wonderful stuff with about the same resonant characteristics as plywood. It's too stiff to contribute anything meaningful to the sound of an amp unless you use extremely thin boards.

not so. actually the stiffer a material is, the better it is at transferring mechanical energy, ie sound. if it is soft and springy, then it absorbs energy, and "self-dampens". why do you imagine that spruce, for example, was used for airplane frames and acoustic instruments? because it was stiff(and light).
carbon composites and aluminum are also stiff. they have also been used as construction materials for musical instruments.
plywood is not stiff at all. lean a piece up against something and come back in a few days and you will see it bows easily. an equal piece of hardwood does not behave the same. that is why hardwood is generally not used in even the most expensive hifi speaker boxes: because it resonates.

[1950]

Marine ply is assembled using the best water proof glues (being used for boat building, boats in the sea). The glues and wood types are also most resistant to marine "wood eating" creatures, which can bore 1/2" holes, a couple of inches a day in soft wood.
None of this is a problem to most musicians, but I made a small boat 32 years ago and had some 1/2 marine ply left-overs, which I made a 1 X 12" speaker box, based on the EVJ'r's box. Its very heavy, but sounds very nice to me. Gotta rout round the corners, 1/2" radius router bit, then spray paint it black (will this change the sound) one day soon. Sounds good though (to me).

[CurtissRobin]

actually the stiffer a material is, the better it is at transferring mechanical energy, ie sound. if it is soft and springy, then it absorbs energy, and "self-dampens".

I agree that a stiff material transfers energy because it resists internal movement (compression/expansion) that may color or damp the sound or resonate. "Soft and springy" may absorb energy but in materials rigid enough to use for building speaker cabs it also returns most of that energy to the air that drives it: elasticity, sympathetic vibration, resonance and damping are relevant physical attributes. Pine is the wood of choice for the Tweed crowd because it responds to the amplified vibrations in those ways and adds its own character to the sound.

why do you imagine that spruce, for example, was used for airplane frames and acoustic instruments? because it was stiff(and light).

You get partial credit for this one. Spruce has straight grain that is spaced closely and is evenly distributed. The close spacing makes it stiff and strong and the even distribution means that there aren't stress concentration points. Avoiding concentration of stresses is vital in the physical strength of airframes and in getting balanced frequency response from a guitar's soundboard. If you've ever played an instrument that had one booming note or one dead note you've heard the effect of uneven grain.

...plywood is not stiff at all. lean a piece up against something and come back in a few days and you will see it bows easily.

Now, that's just silly. The same can be said for concrete or steel. Haven't you ever noticed that "flatbed" trailers and concrete structural shapes have a marked upward bow toward the center of the span? This is so they flatten under load. Stiffness is a relative term, not an absolute. Plywood, properly used, is very stiff or very limber according to the application. Most of us use fairly thin (1/2" or 3/8") baffles to get the organic contribution to our sound that comes from sympathetic vibration. OTOH a high power bass cab needs to be RIGID.

an equal piece of hardwood does not behave the same. that is why hardwood is generally not used in even the most expensive hifi speaker boxes: because it resonates.

Generally true but "because it resonates" is not the reason. Every solid material exhibits resonance and so do fluids and electromagnetic waves. All the high end hi-fi speakers I've had experience with have been built of good grade plywood with hardwood veneer or particle board with hardwood veneer or composite, all to avoid "coloring" the sound being reproduced. Particle board is particularly neutral sounding and extremely effective at damping sympathetic vibration.

We who play music are searching for sound colors, not avoiding them. This search yields many acceptable solutions.

KennyO

[jaysg]

There real deal are not 3/4" thick...they're either 1/2" or 5/8"...don't recall which. I offset the speaker in mine. It balances better when schlepping. Also, the thing could be a little taller. I had to cut out a bit of the lower cleat so the speaker would fit right.

[nyazzip]

All the high end hi-fi speakers I've had experience with have been built of good grade plywood with hardwood veneer or particle board with hardwood veneer or composite, all to avoid "coloring" the sound being reproduced. Particle board is particularly neutral sounding and extremely effective at damping sympathetic vibration.

exactly. (well actually plywood is better than particleboard/chipboard/MDF because the high amount of resins they use to bind the latter stuff imparts its own rigidity and sonic character)
that was the whole point of my post. and that is why i recommended steering away from solid wood plank in any speaker box, guitar, bass, PA, keyboard, or hifi: because generally one wants the sound of the guitar and the amp circuitry, and not the box it happens to be booming out of. been there, done that, as stated.
it can be nice when a box colors the sound, sometimes, but mostly it is a pain in the a** that you just can't simply EQ away. if you are one who likes to play with many different sounds and styles, you will most likely want an acoustically neutral, ie PLYWOOD, box.
i am not a proponent or proprietor of the engineered wood or chemical industry; generally i hate the stuff, and i love natural woods. but i'm politely suggesting, based on some experience, that solid woods can impart some tones that may sound ok at some volumes with some amps in some rooms, but its generally a better idea to construct a neutral sounding speaker box if possible.
regarding the "silly" comment, sure ok. i suppose you could brace the heck out of something to make it more rigid, but in doing so you add mass, which makes comparison invalid. pound for pound, shape for shape, plywood is not as stiff as hardwood, and there is an acoustic consequence of this- like it or not, believe it or not. thanks for granting me "partial credit" though. now i can sleep tonight.

[rmroza]

Ok. It's been a little while and of researching or finding someone to build the thing for me. If anyone does this and wants to, let me know.

I found a hardwood mill within an hours drive here in Michigan. I'm wondering if I just take my time and do it myself and save money, what type of wood would be best?? Can you guys help??

I was going to go with the magnificant "show" quality (as well as hardwood) of say Flame Maple. Then some guitar players and friends thought it might be bright. Personally, I like bright and can take some out, but other alternatives they've offered are Mahogany and Walnut.

What are you're guyz' thought?? Thanks in advance.

Robb

[CurtissRobin]

I Googled "custom hardwood guitar cabinets" and came up with 400,000 hits with several familiar names on the first several pages. If only one in a thousand is worthwhile you still have 400 hits to pick through. If I wanted a hardwood cab I'd go to a local furniture builder. I've done that in several places I've lived and gotten some beautiful furniture, including a hickory display cabinet for my Les Paul-autographed guitar. Go to your prospective builder with a good dimensioned three-view (plus details) drawing set and some photos you've pulled off the internet to give him a clear idea of what you want. If it costs a bloody fortune (it surely will) then ask him for a price to provide the wood and to cut the parts for you to assemble, sand and finish yourself (which will save less money than you'd think).

Bright or not, "flame" maple won't be available in the dimensions you need for a cabinet unless you use straight maple and put on a flame maple lamination a la Gibson's LP construction. Among hardwoods, look, too, at oak, cherry, alder, teak (wait'll you see what teak does to your cutting tools), ash, birch, hickory, et al.

KennyO

[Pressed_Rat]

Among hardwoods, look, too, at oak, cherry, alder, teak (wait'll you see what teak does to your cutting tools), ash, birch, hickory, et al.

I really like the look of ash. It is very hard to work, and a son-of-a-gun to grainfill, but when done right it is very nice. Mahogany is a good hardwood too; easier to work than ash, but also requires grainfilling. It looks very nice too.

I don't think you can go wrong with either.

[rmroza]

Well I have a builder selected if I go forward. It will cost me a little bit of $$$, but he CAN do it in Flame and showed me previous pictures he's done for customers and it looks amazing or Mahogany or the like and I guess you get what you pay for, right. The lead time will probably be 6 weeks (or more)!

I looked up wood characteristics and indeed Maple's are bright. To be quite frank, if it weren't for that, I'd just put together or order a Flame Maple. IMHO, it's the most flashy by far.

I was suprised that Walnut is brighter also (not as much as Maple, but it is).

I really do want this to be more even and warm and would more closely match the wood in the LP's. It's more rich and regal and less flashy...but still hardwood and very nice looking.

I think my decision is made and I'll go forward and do a solid Mahogany 1974X cab. I appreciate everyone's input thou and will attach a photo of a flame cab. Enjoy!

Robb