Nuts and Volts - March 2015

but getting up into the range where I might not consider it audiophile quality.

The sound itself was clean and neutral through the middle of the range (if a bit thin sounding), and not unpleasant or fatiguing at all. At the high end of the power output, though, a noticeable hiss came up from the background and the distortion became quite apparent. The audio was still very intelligible, however.

One thing about this module is that it would definitely benefit from a heatsink. After about five minutes playing at the full rated volume, a whisp of smoke arose from the QA sticker which was on the top of the chip. The thermal cut-off killed the output. I think in a real world application, it's unlikely to be run deep into the red the entire time, so I don't see this as a huge problem.

Smoke coming from electronics is never a fun sight, but there was no actual damage. It fired right back up after cooling off, and its performance was unchanged.

The chip is large enough that it would be easy to fit with a heatsink for better thermal performance, and that would almost certainly solve the problem. If you're mounting this in a small enclosure without much ventilation, it'd be a very good idea to include one.

I'd recommend this module for any application that might actually play back music based on its good performance, or where picking out fine details of the sound over speakers might be important; for example, in something like the Big Ear project referred to in Photo 19.

A Flexible, Full Stack Solution

The second of the TA2024-based amplifier modules is the Dayton Audio DTA- 2 digital audio version. This one goes the opposite direction of the bare board: It has a power connector (although there are solder pads for a hard-wired power supply); a 1.8" stereo mini jack for the input signal; and a volume knob with an integrated power switch on a second small printed circuit board (PCB)

connected by a flexible ribbon cable (Photo 20). There's also an LED power indicator which I didn't assemble for these tests. The speaker leads need to be soldered to the board which is a little annoying, but not PHOTO 20. The DTA- 2 digital audio amplifier module with all of its pieces.