That is the exact part actually.



Thank you for the information!

Your pictures are very helpful, now it seems like it is even easier then I thought.

In your top down picture is the part at the bottom mounted in the wood something like this?
https://www.parts-express.com/2.5mm-Metal-Panel-Mount ...

So a few answers based on completing mine (ok completed is a bit of an overstatement, it works fine but it is currently mounted on pieces of scrap wood until I decide what I want to add before figuring out a final box for it.)

1. On the resistors I soldered wires to both ends just to simplify my ...

Regarding the switch: 2 of those will work the way you show as they have the capability needed BUT ...... I use a single DPDT switch of similar specifications. With 2 switches you will not be able to abort as quickly as with a single switch.
With the DPDT switch you will turn it on after turning ...

To satisfy my own curiosity I purchased the exact BOM from Parts Express above to test out.

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I found that the volume control has an off/on switch. The amp does not pop or produce any spike when turned on but makes a fairly pronounced one when turned off. It is not suppressed.

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I think ...