Pictures of your diy Pass amplifier

[oneplustwo]

In case you missed it.

[NYCOne]

What are folks experieinces with making cases for Pass designs out of wood? I've seen a few photos in these pages, so I know people are trying this.

My questions are more about long term durability and safety:

1. Does wood dry out over time from heat exposure?
2. Does the wood act as an insulator, raising the temperature of the amp?
3. Over years, is there a fire hazard?

I was considering Bubinga or Macassar Ebony for the front and back, and heatsinks on the sides. I hadn't come to a conclusion on the top and the bottom.

[KatieandDad]

1. Well seasoned wood should be dry to start with - so no it won't dry out.
2. Not significantly. Yes an alluminium panel will absorb a bit of heat on one side and radiate it on the other, but nothing compared to the heatsinks.
3. Wood requires one of two condtions to ignite. 1) A flame - this could occur if something was arcing but the arcing should surely be supressed by the fuses protecting the amp. 2) A considerable amount of heat - I'm talking about 300 Degrees C. Most electronic components would have given up long before that temperature was reached. - So no it wont be a fire hazard.

If a hot running resistor is touching wood then you might see some blackening but it wouldn't catch fire. It might if it was in an oxygen tent.

[NYCOne]

Originally Posted by KatieandDad

1. Well seasoned wood should be dry to start with - so no it won't dry out.
2. Not significantly. Yes an alluminium panel will absorb a bit of heat on one side and radiate it on the other, but nothing compared to the heatsinks.
3. Wood requires one of two condtions to ignite. 1) A flame - this could occur if something was arcing but the arcing should surely be supressed by the fuses protecting the amp. 2) A considerable amount of heat - I'm talking about 300 Degrees C. Most electronic components would have given up long before that temperature was reached. - So no it wont be a fire hazard.

Thanks.

I don't have easy access to metal cutting tools, but I can handle wood. Making Pass amp enclosures is a lot easier in wood than aluminum or copper.

[evanc]

Oneplustwo,
I followed your build thread. Glad you got it working.... Looks super. You must be proud of the result after the work you put in

Wood cases seem fine for amps, but maybe not projects that need the shielding of a metal chassis.
Evan

[AndrewT]

Wood dried in the open air eventually comes to ~20% moisture content.
Brought indoors to a heated and drier atmosphere, it will dry out even more, usually towards 10% moisture content.
Wood laid on a heated floor dries to ~6% moisture content. I would expect wood around an amplifier to come to a similar figure.
So the answer is very much a yes. From ~20% to ~6%.

Fire hazard: no. Source of fuel: yes.

Insulator: yes !!!!!! This needs a lot of design input to ensure the amplifier can work in the operating temperatures you will impose.

[KatieandDad]

I would put some LARGE holes above and below the caps to help them keep cooler. It will still get very warm inside an unventilated case.

I even ended up fitting two 50mm fans above mine, all-be-it only running at half voltage to keep them quiet.

[KatieandDad]

Originally Posted by AndrewT

Wood dried in the open air eventually comes to ~20% moisture content.
Brought indoors to a heated and drier atmosphere, it will dry out even more, usually towards 10% moisture content.
Wood laid on a heated floor dries to ~6% moisture content. I would expect wood around an amplifier to come to a similar figure.
So the answer is very much a yes. From ~20% to ~6%.

Fire hazard: no. Source of fuel: yes.

Insulator: yes !!!!!! This needs a lot of design input to ensure the amplifier can work in the operating temperatures you will impose.

True, but in his context it's quite safe to use.

[jacco vermeulen]

You can always line the inside with metal foil.

Just think how many valve radios and TV sets have been manufactured with a wood frame.
Check out John's artwork in wood : http://www.diyaudio.com/forums/attac...d-im001616.jpg

[buzzforb]

Wow. Who is this Jon. THat is a work of art.