Nuts and Volts - March 2015

the end of the world. There are holes for power leads for a hard-wired application in parallel with the power jack, too.

At first glance, this one looks like it should dissipate heat a bit better than the other TA2024 module. There's a large thermal pad on the bottom of the board — even some traces on the top are designed for dissipating additional heat — but it only has one onboard filter capacitor; the rest of the components (except for the output filter inductors) are all surface-mount (Photo 21).

Since it's based on the same chip as the other TA2024 module, it will have the same maximum ratings. This one didn't quite measure all the way up to spec, but I'd be comfortable recommending it for more ambient applications where volume and packaging are more important than sound quality.

Distortion rises steadily — although not too quickly — up to 11.4% THD+N at full rated power into a four ohm load, but through much of the range there's little to no background hiss which makes the sound much cleaner overall (Photo 22). That's right where the datasheet says it should be in the end, although it is supposed to be mostly clean and flat until the high end of its power bandwidth.

Like its connector-less cousin, this one also went into cutoff when running at high power for several minutes, but since that's not really likely to happen in most real world applications, it isn't a huge problem. Again, a heatsink should clear that right up. It doesn't sound terrible, but at higher power there's a bit of hiss and the several percent distortion is easy to notice.

Since the Dayton Audio DTA- 2 doesn't quite manage audiophile-quality sound but is still very listenable, I'd recommend this one for projects where music isn't the main focus, but you might still want to play music on occasion and have it be enjoyable. It would also be great for public address (PA) applications, like haunted house Halloween projects such as the ones in Photo 23 and Photo 24. If you're playing spooky sine waves or monster screams, it doesn't need to be super clear as much as it needs to be loud.

The flexible mounting options (the on-off/volume control is able to be mounted separately from the amplifier itself) mean this could fit into a variety of enclosures, too — even with both boards, the footprint is considerably smaller than the other TA2024, so it could do well where audio was something of an afterthought. It might also make a good outdoor Bluetooth speaker set where you wouldn't be able to notice the distortion as much.

Final Thoughts

Designing your own amp can be a fun project, but in most cases where you need some volume but don't much care about the specifics, a module like one of these is the way to go. Based on my results, any of these modules has good potential for a variety of different applications. The PAM8610 would shine in lower powered, non-musical projects where size is a factor. The model TA2024 amplifier module and the Dayton Audio DTA- 2 digital version (both based on the Tripath TA2024 class T amp chip) do a great job and provide more power at lower distortion.

If you're building a project that's primarily musical, I'd recommend the model TA2024 on account of its audiophile-grade performance. For hybrid applications like sound effects or where you don't quite care about the sound (like a DIY Bluetooth speaker project), I'd recommend the Dayton Audio DTA- 2 digital audio amplifier module.

All of these modules are quite efficient and would be easily powered by a lead-acid battery. Or, you could add a switching boost converter if you have a smaller project that's powered by some LiPo cells or other batteries with a lower voltage but high power density. If you're like me, you probably have a few 12V mains power supplies lying around already. An old computer power supply or even discarded wall warts could easily power any of these modules for your next built-in project.

The modules I’ve covered here will also integrate easily into an existing project, which is part of what makes them a good bargain. You can unlock your gadget's audio potential. Happy hacking! NV

PHOTO 23. The Dungeon Keeper — an animated Halloween prop which would go well with some powerful sound effects (Nuts & Volts, September 2009).

PHOTO 24. The Prop Dropper — a spooky Halloween project which certainly could use a punch in the audio for ambient effects (Nuts & Volts, October 2009).