Quantity   Component name
1 × Raspberry Pi Zero Could also be any other raspberry pi
1 × Some sort of case I've used a crane remote and replaced the emergency button by a momentary switch version.
1 × Polyvection PlainDAC(+) One of the most compact DAC boards I could find; https://polyvection.com/shop/plaindac/
1 × A 5v lithium battery controller with fitting battery cell. The power consumption of the Pi Zero is pretty low so pretty much any auxiliary usb battery will do fine. I aim to use it primarily to ensure safe shutdown when the device gets unplugged.
1 × A usb wifi adapter with known accesspoint support unless you plan to use it in client mode only