This is the sort of thing that people usually put together as a DIY project. Basically,
you put a microcontroller in a box with some memory (either an EEPROM module or a memory
card), an DIY amp on a little daughter board, and a bunch of sockets for the
You can certainly put something together that meets most if not all
of your requirements. But the way you achieve that depends on how much you already know,
if you are prepared to learn some new skills, and how good your soldering skills are.
Two platforms worth considering are the Raspberry Pi
, which is a £35/$35 computer that is actually
overpowered for what you want to do but fits into a cigarette pack and carries a lot of
the connections you need, and the Arduino
which is a much lower powered microprocessor which can also be
made to do what you want. PIC microcontrollers are also a good alternative to the
To get these devices to talk to a PC over USB does require some more
advanced programming skills and often involves writing a small application to run on the
PC. So I would be more inclined to use something like an SD card to store your WAV. You
can copy the file over on any computer with a SD reader and then just pop it into your
Most of these devices use 3.3V or 5v DC supplies, so if you want to
have the option of running from 12V DC you need to put some work into your power supply to
make sure it can dissipate the heat generated when you step down to the internal voltage
required. I would also suggest that you picked your audio power amp kit/design early in
the process because it's power requirements will dictate a lot of the choices you have to
make. A lot of these microcontroller boards can supply power to peripherals but can only
supply 50 to 200mA and some of that will be needed for memory cards, displays, etc.
If you are thinking about this as a DIY project, let us know so we can move this
to the DIY forum. There are probably more people there who can help. And PLEASE let us
know where in the world you are, it does help us point you towards reputable suppliers
close to you.
Largely, but not entirely, dysfunctional.