Hey, Jeff -- I would call it a "limited standalone device," closer to a 2.1 power amp than to a full-featured integrated amp like a KA-7002. It has only one line level input, via a 3.5mm TRS jack -- no phono preamp or DAC. There are separate gain knobs for the L+R and subwoofer outputs, and a knob labeled "STEREO" that's actually more like an old-fashioned tone control -- it's odd in that it actually boosts midrange and treble unless it's set fully counterclockwise for what sounds to me like flat response. Just to clarify the prices, the amp cost me a little short of $50USD shipped -- the $22USD number was my shipped cost for a 48VDC 10A SMPS to power the thing. The amp is based on two TI TAS5630 -- or perhaps the newer TAS5630B, not sure because I haven't peeked under the heat sink -- Class D output chips that conservatively can deliver about 125 WPC with admirably low THD+N into my 8 ohm JBLs (BTL mode) and well over 200 watts for my 4 ohm subwoofer (PBTL mode). Honestly, the thing is almost unimaginably loud and clear -- it really blows my old KA-8002 and even my "audiophile" Adcom right out of the water, with comparable THD+N and far more sheer power.