• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

SimpleSE Under Chassis Mounting

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I can't seem to find the information at the moment, but I'm sure one of the other SimpleSE builders would be able to tell me what size the standoffs are used for under chassis mounting. I believe they are to be 1/2 inch long, but can anyone tell me the fastener size and corresponding screw size?

I'm in the process of building my enclosure, which the top plate has been machined. (being a student I worked in the shop at school- it takes A LOT of time to precision machine a top plate!) All I need to do is drill and tap the mounting holes for the board itself.

Pictures should follow soon enough :)

I kinda cheated and I used bolts and rubber grommets. Then I sandwiched the PCB using nuts and toothed washers. Ain't pretty, but I could make any fine adjustments so the spacing would be right on.

The size can be anything that will fit through the holes. :smash: I think I use a #8 size bolt/nut?
I don't know what others are using, but I am not using spacers. I use a #6 or #8 screw that is 1 inch or 1 1/4 inch long. Thread it through the chassis from the top, and put a nut on it and tighten it. Then thread on another nut, stopping about 1/2 inch above the chassis (from the bottom). Then add the PC board. Adjust the nuts as needed to get the tube sockets at the right height. Then add a washer and another nut to hold the board and tighten them from below using a nut driver.
Think I did the same as TubeLab. However, all you need to do is measure things after soldering up the components. You need to have the chassis and board far enough apart so that the above board components don't touch the chassis, yet close enough for the valve sockets not to be (too far) below deck.


I used either 3/4" or 5/8" threaded plastic standoffs. The screws are #8-32 button heads. You could use shorter standoffs, but I didn't want to see the white tube sockets above the top of the chassis. I made the holes for the tubes a bit oversized to allow for some ventilation.

The only components I put on top of the board are the tube sockets. Everything else is underneath.

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