I just got a request from someone who wants to CNC a front panel for his Muffsy MC Head Amp, and he wanted to use the logo and the font that are on the printed circuit boards.

OSIFONT - The CAD Font

The font used on the PCB is the built-in vector font in Eagle, which is proprietary. The Eagle font is really similar to the "official" CAD font OSIFONT. Which is, I'm sorry to say, proprietary.

Luckily, Github user hikikomori82 has made an open source variant of OSIFONT:

The "Muffsyfont" - The OSIFONT to a T

I thought the lower case "t" looked wrong, so I changed it, and now it's the Muffsyfont.

Download the Muffsyfont here.

And Finally the Logo

The logo is a bit easier though, I can share that with anyone. And by virtue of placing it on this site, it becomes open source as well.

Download the large PNG with transparent background here.

While I've been sharing a lot of my work on muffsy.com, I've never really clarified how my view is on people using my work (or derivates of it). This is now changing.

I've decided to release all of my content (barring a few exceptions) under the Creative Commons Attribution 4.0 International license.

What does it mean?

It means that everything on muffsy.com, except where specifically stated, is open source. You have the right to:

If you're going to use any of the content on muffsy.com, you will have to adhere to these conditions:

• Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  
• No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
• You do not have to comply with the license for elements of the material in the public domain or where your use is permitted by an applicable exception or limitation.
  
• No warranties are given. The license may not give you all of the permissions necessary for your intended use. For example, other rights such as publicity, privacy, or moral rights may limit how you use the material.
  

There are also some conditions for muffsy.com to follow. Most notably is that the shared information must be in an open format. The only possible violation to this are my Autodesk Eagle design files. They can be used, but not always processed, by the free version of Autodesk Eagle. They can also be opened and edited (although not always perfectly) in the open source tool KiCad.

What are the exceptions?

The only exceptions to the Creative Commons on muffsy.com is for a few of my PCB designs, mainly variants of those that I'm currently selling. They are free for personal or non-commercial use, but you cannot use them commercially without my approval.

At the time of writing these are the only exceptions:

• https://www.muffsy.com/blogs/post/Make-Your-Own-Muffsy-PCBs
  
• https://www.muffsy.com/blogs/post/Make-Your-Own-Muffsy-Power-Supply
  

If not stated otherwise, everything is free to use as described above. That's right, text, pictures, schematics, design files. The lot!

I'd really like a stereo input selector with relays, but those things are hard to find! (Apart from some of dubious quality on the *Bay)

Better make my own then. This one's got a custom footprint for an ESP32 devkit module, but it can also be controlled with a rotary switch.

I decided to use five Panasonic TQ-2 relays. The ESP32 module and relays are powered separately, power ground and signal ground are separated to avoid injecting any clicks, pops or noise into the audio channels.

The whole project is open source, free to use as you wish. Eagle project files, gerbers, the Eagle library for the ESP32 module and BoM are all available on the hackaday.io project page.

And, wouldn't you know, Hackaday presented this little side project on their blog!