Amplifier case

I've made 2 of these but have been avoiding uploading these because the electronics will be beyond some people and I will not accept responsibility for damage caused by anyone building one.

This amp follows the same design scheme as the Squeezeboxen case and the SqueezeAmp cases. There will possibly be a future Merus MA12070 version but this one is based on the Adafruit Max9744 board, which actually sounds pretty good for near field monitors.

The rotary encoder handles volume and mute functions and uses the Adafruit I2C Seesaw breakout board. IR and the volume I2C logic are handled by a Raspberry Pi Pico. The IR is a TSOP38238. Others have a slightly different shape and may not fit correctly.

The volume display is a TM1637 4 digit, 7 segment, digital display that Displays volume, status (such as mute) and error codes during startup.

As for the other modules in the series, this is tuned for ABS but the feet are TPU95. rather than use expensive Bus Bars, I use M3 screws and cables terminated with ring lugs, that screw into heat set inserts.

This version also has a DC power filter like this one but it doesn't really make a noticeable difference. I was trying to eliminate some hum from my Spectrum analyser and bought a bunch.

The volume control knob was designed in OpenSCAD so I could texture the outside but is limited to the half-shaft type connection. I tried to make a light channel so that the LED of the rotary encoder breakout would light up behind the knob but didn't have much success. I may revisit this at some point and add a channel for reflective tape or something to create the effect I was after.

The rear panels have multiple parts so that MMUs can be used to create different coloured text. If you don't have an MMU, delete the text parts.

The MAX9744 board effectively also has an analogue audio pass-through, which is why there is an output as well as an input. I use the output to power either VU meters or a spectrum analyser that I've also designed in the series.