I've just comlete my first semi-DIY amplifier. It's working great!

I was/am very a happy with my Monarch Audio SM-70 Pro monoblocks, but I undertook this build with a few objectives in mind:
  1. I wanted a fairly simple, first audio project to amuse me in my recent retirement.
  2. I wanted more in depth exposure to a digital amplier. I want a comparision no only with the high-bias, low feedback Monarchys, above, but also with the Bel Canto eVo2i, Tripath-based I owned a few years ago, (based on my memory 'cause the Bel is long gone).
  3. See if substantially more power would make much of difference in my usage, say 2.5x the 120 wpc @ 4 ohms of the Monarchys.
What tempted me to this project specifically was the US-made, Class D Audio, (website here), amps. Their amps are based on commecially available "class D" chips, however the boards and circuitry are proprietary. I selected the SDS-258 (here) model, actually the kit that includes a linear power supply, transformer, and gain pots for US$360, (here).

The biggest challenge wasn't the electronics, which are basically plug-ang-play, but the cabinet construction. This was something new to me and I made a dozen mistakes along the way, but fortunately none were show-stoppers; (first time I've owned or used a "step drill"). Class D Audio can also supply a case, but it was a little rich for me at $190; my own case included some 1/2" MDF, 1x4" pine, and a Hammond aluminum case botton: this stuff cost me about $20. Assorted hardware including Neutrik XLR connectors rounded up the price to about $420 plus shipping.

The SDS-258, according to CDA, is ingeniously designed for balanced input and that's the way I built it since my preamp has balanced output. (Single-ended is also supported.)

My first impressions of the sound is very possitive -- more to follow. Here's a pic ...