What is it?

This is the revised edition of the HoustonTracker2 headphones amplifier PCB. HoustonTracker2 is an application for TI calculators (83+, 84+, and some others) which allows composition of stereo 1 bit audio. The result is a very chiptune sounding instrument which can be a lot of fun.

Why did you make it?

I made this because the original design, used with permission from 'Snorkel,' did not have barrel connectors for power or audio, nor a power switch or battery input. This update addresses those conveniences.

Updates were:

Added power switch ("Breadboard Compatible")

Added 9V DC "Breadboard Compatible" Barrel connector, accepts a standard 9V center negative power supply, i.e. from most guitar pedals.

Added solder terminals for optional 9V battery (DC Jack disconnects battery positive when inserted, so DC Jack power takes priority)

Note: The barrel connector must be installed for the 9v battery circuit to be completed.

Added 3.5mm barrel jacks for input and output (use a 2.5mm to 3.5mm headphones cable to connect the calc to the input)

Added spots for optional RCA jacks. This version will disconnect RCA output when a jack is present in the headphones output connector.

Original power terminals labelled TP1/TP2 can be used for a 2-wire voltmeter, which can be affixed (glued) to the DIP IC.

What makes it special?

This amplifier ONLY works with 1 bit audio from the TI Calculator (To be fair, it might work with a single line of a serial communication as well but that has not been tested). Normal audio will not pass through.