My little sound systems

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   So a couple of years back I decided it would be a good idea to build a portable sound system, the main motivation was something to use when slacklining with friends (google it if you've not come across it). My budget was basically <£5 (spent too much on other hobbies lol), so I bought a cheap battery holder off ebay, I already had a stack of 18650's for high power torches(flashlights), I had an old rubbish car amp, and there was a couple of rubbish speakers in the garage from the previous owner, oh and a switch of a mains electric lamp.
I put it all together and this was the result:
MK1:

It did the job, and I soon realised that I should make a better job of it and put some better speakers on it, I had a single old Bang and Olufsen speaker that my late granddad bought from a charity shop for £1, over the years it had been used as a centre speaker, a computer speaker, and was then just sat in the garage. so I saved it from rotting in there and put this together (together with an old hifi bookshelf speaker I had) .
MK2:

This proved a bit heavy, there were times I could do with something a bit lighter.

Years back I had driven this speaker of an amplifier I made based around the LM380 and although pretty low power kicked out a reasonable amount, I figured this in the smaller speaker would be handy then bring out its big brother when needed.

I couldnt find the old circuit I made, in the meantime whilst looking I ordered a bluetooth module, theres not much to the amplifier so I made another one. note the blue thing on the battery pack is a self resetting circuit breaker.
MK3.0:

Now before this was even hooked up I had done some googling and realised how cheap efficient D-class amps can be had so an order was placed for a <£5 TA2024 board form china (no doubt the more expensive ones will be better, but it works and thats all I need).

Now it has arrived and its time to put the electronics into the housing:
MK3.1 (pre-assembly):

Ive mixed the left and right together via 2 1K resistors.
Ive changed the feedback resistor so I can get volume out of the crappy ipod (phone and bluetooth were fine)
I'll be putting the bluetooth module inside too, Ive used a DC to DC isolated converter (else it buzzed big time), I only and a 5Vout one to hand to bodged on a 3v3 linear regulator, not the neatest or most efficient way of doing it but it doesnt pull much current anyway so Im not worried about it. (and the bluetooth can be switched off and driven by 3.5mm jack).

I thought I'd post up, firstly to motivate me to finish, and secondly to help inspire others that 12V soundsystems can be built simple and cheap so if anyone want to build one they should. I have a friend 100 miles away who isnt as technical as me, but hes building one (when the bits arrive from china). Basically all you need are some batteries, fuse (car one will do) amplifier PCB, speakers (the more efficient the better, but if you have some laying around why not just go for it!).

Edited by Sm1thson - 28 February 2014 at 11:15pm