Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: roboDNA on November 06, 2025, 08:43:45 am
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Hello,
What quality of pine is typically used by builders when manufacturing cabinets? I don't want to go over-kill but am hunting for the very best wood for my build(s), within reason.
For my Fender 6G15 cabinet build, I'm currently looking at getting some high quality eastern white pine grown in northern Canada ( long winter slow growth, tighter grain ). The wood is is knot-free, clear white color ( no dark patches ) , kiln dried to around 8%-10% and no warping. I should be able to get B or better grade from those for my build, which is wood grade typically saved by the sawmills to sell to veneer manufacturers. The source is a sawmill which has operated 60 years so I know I can get more for my next builds without doing all the leg work again.
Does anyone else have tips or info. on what high quality pine they source before I pull the trigger on this wood? ( requires 'large' minimum order )
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From what I found:
Southern Yellow Pine (SYP) and Eastern White Pine (EWP) are recommended choices.
SYP is very strong and dense, one of the hardest pines, more challenging to cut, shape and sand due to its density, readily accepts stains and finishes, though it may need a "spit coat" of shellac to prevent splotching.
EWP is softer and less dense, easier to cut, shape and sand (can be prone to dents and scratches), holds paint and finishes very well, making it easy to stain nearly any color due to its porous nature and light color.
Also baltic birch plywood for its balance of durability, strength, and tonal qualities.
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From what I found:
Southern Yellow Pine (SYP) and Eastern White Pine (EWP) are recommended choices.
SYP is very strong and dense, one of the hardest pines, more challenging to cut, shape and sand due to its density, readily accepts stains and finishes, though it may need a "spit coat" of shellac to prevent splotching.
EWP is softer and less dense, easier to cut, shape and sand (can be prone to dents and scratches), holds paint and finishes very well, making it easy to stain nearly any color due to its porous nature and light color.
Also baltic birch plywood for its balance of durability, strength, and tonal qualities.
Good to know about SYP, I'll take a look. I know the EWP I'm getting is more dense than usual since it's from up north. I'll have to do a SYP build now to check it out.
For the BB, I noticed the Home Depot Birch plywood is not as good as the baltic/european imported B/BB or BB/BB and more easily has tearout. I just did a build with european B/BB and have zero tearout and it's super flat. ( see pics ) The Home Depot BB seems to have knots and air pockets as well which is a problem for finger joints where some of the epoxy breaks off leaving a gap.
I noticed the 1/4" baltic birch is slightly curved no matter where I get it, even from a fresh stack. Would it make sense to do my back panel for my 6G15 cabinet in 1/2" BB instead of 1/4"?
I also noticed sanding some BB results in darker patches but does not seem to be an issue with the imported.
Here are some of my pics showing results from the better quality BB ( before sanding and edge rounding ) with no tearout and 'perfect' square corners.
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I love Baltic Birch. But I have had the same trouble with the 6mm (1/4") version. Using 12mm ply is stiff and flat, but adds too much weight IMO.
My workaround is to rout a rabbet into the back of the cabinet so that the 6mm ply is supported on all sides. If I need to leave one side "flapping in the breeze" eg unsupported, I'll reinforce that by gluing an additional piece of the plywood so that the unsupported part is double thickness. (All you need is about 3/4" wide to do this). Hope this makes sense, but if you need photos I can rustle some up maybe.
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I love Baltic Birch. But I have had the same trouble with the 6mm (1/4") version. Using 12mm ply is stiff and flat, but adds too much weight IMO.
My workaround is to rout a rabbet into the back of the cabinet so that the 6mm ply is supported on all sides. If I need to leave one side "flapping in the breeze" eg unsupported, I'll reinforce that by gluing an additional piece of the plywood so that the unsupported part is double thickness. (All you need is about 3/4" wide to do this). Hope this makes sense, but if you need photos I can rustle some up maybe.
Apparently the 1/4" also 'resonates' different but I can't currently envision that for the reverb tank. My BB build(s) have a nice sound when I knock my knuckles on them. I doubt the 6mm has anything to do with the tone but interesting Fender uses that width. Maybe it needs the thin/open back for some reason. I know the holes are there keep the tubes cool. Also, could it be thinner to prevent it from getting as hot as 12mm? Again, I can't see that but I've read that somewhere before.
For my recent build, I made 2 back panels, one 1/4", one 1/2" with the 2 cleats inset 1/2" to accommodate both.
NOTE: I noticed BB/BB is not available in 5'x5' sheets, only 4'x8'. The B/BB is only available in 5'x5'. One is rated for outdoors, uses a different epoxy and is a bit thicker.