[ohenry]

After seeing continuing interest here in the small Tripath based class D amps, here's another avenue a friend told me about (and gave me).

http://www.jerryselectronics.com/diykits/kaa03021/kaa03021.htm

It's a Texas Instruments class D amp based on the TPA3122 IC (15+15 watts).  I've built one and with the usual tweaks, it sounds very nice.  It's an easily built kit having through-hole construction.  If you are in the U.S., it'll quickly come to your door for $24.95. Sweet, good, cheerful and cheap.

I haven't compared it directly to the other small class D offerings I possess, but it sounds as good as my other t-amps from my flawed audio recollection skills.  If you like to build things, this is a fun project and offers easy parts substitutions since you are populating the board.  It's refreshing not having to desolder stuff.  And yes... the short circuit protection seems to work.

Here is a description taken from the website:
"A great little digital audio amplifier, it's super efficient design draws only 30 ma @ 12 volts when idling. The TPA3122D2 ic comes from Texas Instruments and features automatic thermal and short circuit protection. It doesn't require a heatsink when playing music so it will not burn your fingers like analog amplifiers. I've hooked this amp up to 3-way floor speakers with a 10" woofer and was amazed at the volume level, sound quality and punch from one little ic, I know you won't be disappointed.

What’s Included in the kit:

1 - High quality PC Board
1 - TPA3122 Class-D Audio Power Amp IC
4 - 470ufd Electrolytic Capacitors
4 - 1ufd 50v Ceramic Capacitors (105)
2 - 0.68ufd 50v Ceramic Capacitors (684)
2 - 0.22ufd 50v Ceramic Capacitors (224)
3 - 0.1ufd 50v Ceramic Capacitors (104)
3 - 4.7k ¼ Watt Resistors (yellow, violet, red)
2 - 10k ¼ Watt Resistor (brown, black, orange)
1 - 10k Variable Resistor
2 - 22uh Inductors
1 - LED
1 - Spacer for LED
3 - 2 Position Terminal Blocks
2 - Phono Jacks
1 - 4 Pin Header
2 - Jumpers
4 - PCB Standoffs"

[wushuliu]

I've heard good things about the Jerry kit. The selling point is you know the component quality is good. That said you can the TPA3122 on ebay for very cheap and the TPA3116 is even cheaper and sounds better. And the TPA3110 is only $10 at Parts Express and that also sounds incredible (if you can handle low power). The <50w digital amp options are exploding and many of them sound fantastic and they are dirt cheap especially for those with a little solder skill.