To hook up some old KLH speakers to my computer, I needed a small amp. First up was the ultra-cheap Pyle PFA100, an allegedly 30-watt amp that's just $25. Though it had controls for treble, bass and tone, and jacks for headphones and a mic, it was so bad that none of it mattered. The Pyle was was noisy, distorted at louder volumes, and picked up radio interference. Even accepting the possibility that I got a lemon, it's clearly junk when you see it in the flesh. Replacing the power brick (as some suggest) did not make a difference.
I next considered trying the Lepai 2020, a similarly-tiny product at an even-tinier price. Though it's got a reputation as surprisingly good for the $20 you'll pay for it, I was dissuaded by the fact that it really does seem identical to the Pyle: the same controls and jacks, all in the same places, as if the only difference was the casing. While it only claims 20W output, suggesting at least some different innards, I decided not to be a sucker twice and opted for the Topping TP10.
Though three times the price, at $65, it's a simpler gadget with no mic or headphone jacks, and no bass or treble to fiddle with: signal in, signal out. It also claims only 15W of output, half that of the Pyle. It's nicer on the eyes, though, with a brushed-metal faceplate and superior knobfeel. Most importantly, it sounded much better than the Pyle, with no audible interference and clean audio at higher volumes. 15W seemed enough to drive the KLH Model 19s on my desk.
I don't doubt the happiness of those who report success with modern "fleamarket" amps, but with good alternatives only a little more expensive, why bother risking it? Both models were tested using the same cables and equipment.