# Wooden Amp Chassis?



## Mark Brown (Jan 4, 2022)

So I was wondering, is there anything to stop someone from building an amp chassis put of wood? I can't really see why there should be. 

Build a box, make the top a plate of aluminum for all the grounding and that should be about that wouldn't it?

Maybe load a plate behind the pot/jack area and solder a ground wire to the top?

I suck at metal work and wood and I get along. I am wondering where I might go wrong with a plan like this?


----------



## oldjoat (Apr 4, 2019)

why not ?

dado a slot in the cab sides to slide the flat metal plate into ....


----------



## Lincoln (Jun 2, 2008)

well for one thing, to get the strength and rigidity you need, wood would have to be much thicker than metal. Most pots and tube sockets and thing aren't made for going into/through a 3/4" (19mm) piece of wood. And then there's the fire hazard thing too. What would your insurance company say when fire inspectors tell them the new tube amp you just built shorted out and burnt your house down?


----------



## Mark Brown (Jan 4, 2022)

Lincoln said:


> And then there's the fire hazard thing too.


Pffft, hazard. I am a fire hazard, don't worry about that 

Let us stay concerned with grounding and feasibility. Let me worry about burning my house down 

Pots and jacks would just need to be reamed out so that eliminates that problem. If Gibson tops can work, so can this.

So here is the forming plan in my brain....

Build a base and 4 sides with wood, probably some walnut because it is sexy as hell. Top plate of 0.08 aluminum. All the grounding would fall onto the top plate, or failing that, grounding lugs onto a bus with the PT ground.

I'm just wondering what grounding issues one might have to overcome. As for the function beyond that, well there isn't anything I'm concerned about as they are basically wall art in my house. Wall art that sounds amazing.


----------



## WCGill (Mar 27, 2009)

Nope.


----------



## Mark Brown (Jan 4, 2022)

WCGill said:


> Nope.


nope what


----------



## Paul Running (Apr 12, 2020)

Wood is a poor heat conductor, tube amps require proper heat-sinking...the chassis is the main heat sink of a tube amp and as you know the greater the thickness the greater the heat transfer...16 gauge is ideal.
It also serves as a Faraday shield, when properly designed.
Possibly a fire hazard.


----------



## Mark Brown (Jan 4, 2022)

Paul Running said:


> Wood is a poor heat conductor, tube amps require proper heat-sinking...the chassis is the main heat sink of a tube amp and as you know the greater the thickness the greater the heat transfer...16 gauge is ideal.
> It also serves as a Faraday shield, when properly designed.


Tubes go outside.
I'm hearing a lot of "probably shouldn't" but not a lot of why not


----------



## Paul Running (Apr 12, 2020)

Mark Brown said:


> Tubes go outside.


When I operate my V5 or V7 hard for an hour, the chassis gets quite warm...the heat is mainly from the transformers.


----------



## Wardo (Feb 5, 2010)

Should be OK as long as you use Brazilian rosewood.


----------



## Mark Brown (Jan 4, 2022)

Paul Running said:


> When I operate my V5 or V7 hard for an hour, the chassis gets quite warm...the heat is mainly from the transformers.


Those are top mounted too.

I'm not paying 130 dollars for iron to hide it in a box 

So I'm just gonna do it as apparently the worst thing that will happen is I will need to isolate for interference. I'll report back!


----------



## Paul Running (Apr 12, 2020)

Mark Brown said:


> Those are top mounted too.


The idea is to use the chassis as a heat sink...to transfer heat away from the devices. Top mounted on a wooden chassis means that heat can only be transfered to the air...the chassis is a better heat conductor than the air.
This way heat is transferred and dispersed more efficiently.


----------



## Mark Brown (Jan 4, 2022)

Paul Running said:


> The idea is to use the chassis as a heat sink...to transfer heat away from the devices. Top mounted on a wooden chassis means that heat can only be transfered to the air...the chassis is a better heat conductor than the air.
> This way heat is transferred and dispersed more efficiently.


All of that is true, however look at 99% of amplifier chassis that are cab mounted. Steel/aluminum plate, mounted inside a box with the trannies and tubes orientated to the bottom with heat radiating and the subsequent air rising. So if it were that much of a problem I cannot help but think there would be much more robust engineering to design a solution. What seems to be done is quite literally the worst possibly option from the perspective of heat dissipation.

I'm not trying to argue with you Paul because you are correct and smarter than I am, but I cannot imagine how an open air system could possibly be worse than the classic design. It is probable I am missing something that may be obvious to you as I tend to do with concepts over my head


----------



## Robhotdad (Oct 27, 2016)

Mark Brown said:


> Those are top mounted too.
> 
> I'm not paying 130 dollars for iron to hide it in a box
> 
> So I'm just gonna do it as apparently the worst thing that will happen is I will need to isolate for interference. I'll report back!


What about shielding? What about immunity from RF interference? How about the safety benefits of having an electrically grounded chassis? There are actually reasons why modern amplifiers are built the way they are. I know it's presently fashionable to dismiss everything that has come before us, but..., intelligent human beings have been here for quite some time and adopting some of their tried and true practices, makes plenty of sense. 

I'm presently in the process of acquiring a box and pan brake for the very purpose of fabricating a proper metal chassis for my amps. 130$ is nothing, spend it.


----------



## Paul Running (Apr 12, 2020)

Mark Brown said:


> What seems to be done is quite literally the worst possibly option from the perspective of heat dissipation.


It could be improved by increasing the surface area ie. finned heat-sinking and forced-air which some manufacturers apply to their products.
The tubes alone require heat to operate efficiently however, for most components, heat is detrimental.
I believe that if there was no heat generated or absorbed by these components, there would be many less component failures...heat is a killer for most physical objects.
If manufacturers designed products with ideal heat transfer characteristic, there would be a lot less failures which means that consumers would not need to seek replacements. How would that affect their business?
Products are designed with some failure to maintain business.


----------



## Always12AM (Sep 2, 2018)

https://www.digikey.ca/en/products/detail/lmb-heeger-inc/8103-C-PLAIN-ALUMINUM/268771



A dual 6V6 amp that is cathode biased gets hotter’dn shit.


----------



## Mark Brown (Jan 4, 2022)

You guys are no fun


----------



## diyfabtone (Mar 9, 2016)

It works great and can look so too if done well. It's a tried and true way to build DIY Audio Amps. Components should be on the chassis plate for easiest implementation and there needs to be enough air flow to keep tubes from over-heating - feet to raise the frame at least a 1/4" above surface and vent holes around power tube sockets should do it. Google it - tons of examples. 
If you get EMI or RFI noise you might have to shield the inner frame walls with copper tape and put a metal bottom plate on (make sure ground connection is good and no gaps - bottom plate needs vent holes too.
If also made one with cut outs for a small metal panel with input, output, and power connections in the frame and grounded the panel to top-plate - for a power amp I've never needed to shield but for preamps and especially high-gain guitar preamps shielding is recommended.


----------



## Paul Running (Apr 12, 2020)

If you were building an open-structure you could do this...wood sides with metal top; some high-end audio gear uses this technique.


----------



## Mark Brown (Jan 4, 2022)

diyfabtone said:


> It works great and can look so too if done well. It's a tried and true way to build DIY Audio Amps. Components should be on the chassis plate for easiest implementation and there needs to be enough air flow to keep tubes from over-heating - feet to raise the frame at least a 1/4" above surface and vent holes around power tube sockets should do it. Google it - tons of examples.
> If you get EMI or RFI noise you might have to shield the inner frame walls with copper tape and put a metal bottom plate on (make sure ground connection is good and no gaps - bottom plate needs vent holes too.
> If also made one with cut outs for a small metal panel with input, output, and power connections in the frame and grounded the panel to top-plate - for a power amp I've never needed to shield but for preamps and especially high-gain guitar preamps shielding is recommended.


I knew I wasn't fucking crazy 

Back that up... I am crazy, but I knew this should work lol

That image there @Paul Running lifted from the internets was more or less what my brain was thinking. Wood box, metal top plate back ended input/output controls, pots on top. 

This is why I was asking more about grounding than "feasibility". Seeing as the champ I built has an open bottom and 2 ends and sits 8 inches from a 25" monitor and 24" from a wireless antenna I am not extremely concerned with interference. Old dumpy amp circuits aren't really all that sensitive and even if one encounters it, it is easy to overcome.


----------



## RBlakeney (Mar 12, 2017)

I think that its a good idea, because if you build it and it doesn't work, its better to throw into a fire


----------



## Mark Brown (Jan 4, 2022)

RBlakeney said:


> I think that its a good idea, because if you build it and it doesn't work, its better to throw into a fire


And I have a fire!!

See, now we are talking my language. 

I have discovered a lot of information in my epic amp search come from the mentality of "it always was". Ok, so there is usually a reason, but most the time I cannot find the real reason. It isn't like I am trying to stuff some Triple Rectifier 150W monster into a wee little wooden box, that would probably be crazy. It is going to be a 5E3, it won't likely ever leave my house so being extremely robust isn't a huge concern. I just want something kinda pretty. Functional first and foremost, but pretty never hurt.


----------



## nonreverb (Sep 19, 2006)

Mark Brown said:


> Tubes go outside.
> I'm hearing a lot of "probably shouldn't" but not a lot of why not


All around bad idea IMO. The reasons indicated so far should have already dissuaded you.


----------



## MarkM (May 23, 2019)

Mark Brown said:


> I knew I wasn't fucking crazy
> 
> Back that up... I am crazy, but I knew this should work lol
> 
> ...


Persistently fucking crazy!😝


----------



## knight_yyz (Mar 14, 2015)

__





Wood & Corian vs. metal amp chassis - Techtalk Speaker Building, Audio, Video Discussion Forum


Want a second or third opinion about your speaker cabinet design or other audio related problem? Post your question or comment on the Technical Discussion Board. Hundreds of technicians, engineers, and hobbyists, nationwide read and discuss electronics related questions each week. We welcome...



techtalk.parts-express.com


----------



## Paul Running (Apr 12, 2020)




----------



## Mark Brown (Jan 4, 2022)

knight_yyz said:


> __
> 
> 
> 
> ...


You should go make an account and tell them they are all wrong 

Seriously though, thanks for the link. I am going to go out on a limb and assume there are no real problems with the design other than it breaks with "tradition". Sure, one has to be aware of what challenges may present themselves however I am having a hard time coming up with anything definitive that suggests the idea is outside of the realm of possibility. My only real concern was with the grounding of Pots, inputs and outputs. Would one just run back to the plate which has the grounding for the unit based on the PT grouding?


----------



## Mark Brown (Jan 4, 2022)

Paul Running said:


> View attachment 449478


I don't usually give up even when the answer says I am wrong


----------



## nonreverb (Sep 19, 2006)

Mark Brown said:


> I don't usually give up even when the answer says I am wrong


I commend you for considering it. We nay-sayers may all be mistaken. That said, there will definitely be a learning curve.


----------



## greco (Jul 15, 2007)

Paul Running said:


> View attachment 449458



This is exactly what I thought @Mark Brown was considering. IMHO, it looks cool! (pun is intended).


----------



## Alan Small (Dec 30, 2019)

Remember when?


----------



## Mark Brown (Jan 4, 2022)

nonreverb said:


> I commend you for considering it. We nay-sayers may all be mistaken. That said, there will definitely be a learning curve.


I don't ever want to come across as dismissive. That is not the point, nor my intention. I try to ask legitimate questions and weigh responses. 

I know there is a wealth of information available here to me that is well beyond my understanding and ability and to be frank, I recognize that fact. I do question things however, it is in my nature and is how I learn. I was never one for "face value". Now I won't be running off trying to rewrite Ohm's Law, that is pretty sorted.... but I am having a hard time finding a justifiable reason to dissuade me from this course of action based upon the limited factors I have encountered here. They all seem very easy to overcome and while it might not be the most prudent course of action, that should not eliminate it, no?


----------



## nonreverb (Sep 19, 2006)

Alan Small said:


> Remember when?
> View attachment 449515
> 
> View attachment 449514
> ...


Apart from the phone, all had metal chassis.


----------



## nonreverb (Sep 19, 2006)

Mark Brown said:


> I don't ever want to come across as dismissive. That is not the point, nor my intention. I try to ask legitimate questions and weigh responses.
> 
> I know there is a wealth of information available here to me that is well beyond my understanding and ability and to be frank, I recognize that fact. I do question things however, it is in my nature and is how I learn. I was never one for "face value". Now I won't be running off trying to rewrite Ohm's Law, that is pretty sorted.... but I am having a hard time finding a justifiable reason to dissuade me from this course of action based upon the limited factors I have encountered here. They all seem very easy to overcome and while it might not be the most prudent course of action, that should not eliminate it, no?


I think the rational is that it's all been done before. That's why, where tube amps in particular are concerned, the use of a metal chassis is the convention not the exception.


----------



## knight_yyz (Mar 14, 2015)

you could insulate with phenolic, it looks like wood and can take some serious heat. Put a little fan inside... metal heatsink with thermal barrier pad... copper tape can be bought in sheets if you're worried about EM or 22 or even thinner gauge aluminum is easy peasy to cut with tin snips. I say go for it, the wooden chassis projects I have seen have me gassing to build one now too.


----------



## Alan Small (Dec 30, 2019)

I got the impression Mark intends to use a metal chassis(although he used ambiguous terminology): flat stock(not a box) surrounded with lovely wood frame


----------



## RBlakeney (Mar 12, 2017)

I suggest using a cardboard box for a chassis, they are cheap and plentiful. It also allows you to cut your holes our with simple kitchen scissors.


----------



## Mark Brown (Jan 4, 2022)

RBlakeney said:


> I suggest using a cardboard box for a chassis, they are cheap and plentiful. It also allows you to cut your holes our with simple kitchen scissors.


No man, my kids will steal it. There is no cardboard safe in this house.



Alan Small said:


> I got the impression Mark intends to use a metal chassis(although he used ambiguous terminology): flat stock(not a box) surrounded with lovely wood frame


Top metal plate, that is the extent of metal that should be required. Maybe, just maybe a back plate, but I don't really think so. 

I have taken to the Google since I first posed the question and I have to say, there are some exceptional designs that exist out in the world wide web that one could emulate with what I assume to be varying degrees of success. This will be my path.


----------



## Alan Small (Dec 30, 2019)

Top metal plate, that is the extent of metal that should be required. Maybe, just maybe a back plate, but I don't really think so
[/QUOTE]
Plate and chassis are different words describing the same thing made of metal....chassis does not have to be bent metal..flat chassis are common in many designs


----------



## player99 (Sep 5, 2019)

I'll fight ya.


----------



## Mark Brown (Jan 4, 2022)

player99 said:


> I'll fight ya.


I'm into it. Lets do this 

It is a long drive though, meet in Winnipeg?


----------



## keto (May 23, 2006)

Mark Brown said:


> I'm into it. Lets do this
> 
> It is a long drive though, meet in Winnipeg?


Jesus, yer nutz. It would be worth your while to fly him out to you, just for the climate.🥶

Source: I grew up there.


----------



## RBlakeney (Mar 12, 2017)

Have you considered building an amp in a Tupperware container?


----------



## player99 (Sep 5, 2019)

How to Make No-Cook Paper-Mache



https://www.thesprucecrafts.com/no-cook-paper-mache-paste-recipe-1253087


----------



## WCGill (Mar 27, 2009)

Tasty!


----------



## Mark Brown (Jan 4, 2022)

RBlakeney said:


> Have you considered building an amp in a Tupperware container?


That would just be stupid.....


WCGill said:


> Tasty!
> 
> View attachment 449563


I don't know if I should laugh, or love it, but I know I have a reaction 

If the brownie pan cutting board is an option, I think I am going to be just fine lol


----------



## Always12AM (Sep 2, 2018)

I just came back to check in to see how much shit you’ve taken for asking everyone if you should build an amp out of wood knowing full well that you are going to build it out of wood even after everyone gives you shit for it lol.


----------



## Latole (Aug 11, 2020)

Paul Running said:


> Wood is a poor heat conductor, tube amps require proper heat-sinking...the chassis is the main heat sink of a tube amp and as you know the greater the thickness the greater the heat transfer...16 gauge is ideal.
> It also serves as a Faraday shield, when properly designed.
> Possibly a fire hazard.


100% right,
It is to go in front of problems (as much electrical as mechanical) that to build in wood


----------



## Mark Brown (Jan 4, 2022)

Always12AM said:


> I just came back to check in to see how much shit you’ve taken for asking everyone if you should build an amp out of wood knowing full well that you are going to build it out of wood even after everyone gives you shit for it lol.


You know me too well


----------



## Mark Brown (Jan 4, 2022)

I forgot to tell ya..

I bought my chassis the other day!










It isn't quite assembled, but it has potential.


----------

