The instructions give you three alternatives for powering the Muffsy Phono Kits. Here's another one:

This step-down power module is available on Tindie, and can provide up to two amperes of power. Use two of them and connect a 15V DC power supply at VIN/GND as shown in the picture above, and you will...

This is my first venture into SMD components, so I'm going to have some fun with tools, solder paste, stencils and hot air. :)

Get the gerbers for this side project here: invRIAA.zip

This project is freely available, and you can have the boards produced yourself. That's not for everyone though, so I've decided to sell the PCBs for the BSTRD on Tindie.

Here's another project with freely available Eagle project files.

There was a strange little thing that appeared in Danish magazine Ny Elektronik (New Electronics) in 1989. A very simple preamplifier that used two L63 tubes in Class A with no feedback and it operated pretty much badly out of spec. (...

Here's a little side project, and it comes with Eagle Project files so you can order, etch and modify it anyway you like. All project files are available on this Hackaday.io project page: https://hackaday.io/project/18624-muffsy-constant-current-led-tester