Luke’s DIY Audio Fabrication

Here’s a project done by Luke Emrose this Saturday on the space’s CNC. It looks pretty cool and was made entirely with free tools!

Here’s some wiki info if you want to make a board yourself:

Without further ado, I’ll hand it over to Luke:

Hi there!

Sorry for the big e-mail, but I was excited….
Thanks to some outstanding help from Gav and talsit and a few others at the space this evening, I used the CNC machine for the first time ever ;-)
Even better, probably just through sheer luck, it was very successful too!
Here is the PCB that I made:
The eagle layout and circuit diagram ( which I successfully proved “should work” using the free LTSpice circuit simulator - found from bits and pieces I’ve found online about the API 2520 discrete operational amplifier ):

First the copper etching stage:

Then the holes are drilled for the parts:

Then the board is milled out to it’s final shape:
Here are some “pose” shots ;-):

For those of you still reading, this is a discrete operational amplifier ( DOA ) board, which I designed out of necessity, because the “real-thing” ( an API 2520 DOA ) was too expensive for me ( my board is an alternative for the little square board in this pic ):

Also the “real-thing” is made from a double-sided board.
I wanted a cheaper and simpler alternative so I crammed the entire thing onto a single sided board that was designed to be easy and simple to CNC:
I’m going to use it as one of 8 DOA’s I am building to go into 4 channels of custom-designed compression for my home-studio.
The finished unit/s might somewhat resemble ( I hope ) 4 of these:
but I’m not sure yet, as I am still designing it….
However, thanks to the space, I’m off to a good start.
Next step is soldering the bits on the little board and turning it on and hoping it ACTUALLY WORKS!
Luke Emrose
aka evolutionary theory