I'm currently auditioning a Halcro MC20 driving my left and right front channels, in place of my Proceed HPA2. I'm doing this with the idea in mind of replacing the HPA2 and Proceed AMP3 with either a Halcro MC50 or a Simaudio Moon Aurora 5.

The MC20 is a class D amp with single-ended and balanced XLR inputs (I'm running it balanced from my G68XXV) and 400 wpc (continuous I think, not peak; into 4 ohms). The MC30 is the 3 channel version. The MC50 and MC70 are the 5 and 7 channel versions, but with 375 wpc (again, into 4 ohms; again continuous, I think, not peak). When I compared it to a Simaudio Moon W5.3 in the showroom using a Simaudio CD, Spectral pre-amp, and Magico speakers, there was a clear difference between the Sim and the Halcro. The Halcro was amazingly "accurate", but seemed "dry" and "clinical" in the showroom. The Sim was more "musical" and had more low-end slam, but was not as good at defining each and every sound/voice/instrument. FYI, I haven't trained myself to be able to detect small differences between amps (nto really an "audiophile"), so these were not subtle differences. At home, using B&W Nautilus 802s (not "D") which likely have a warmer sound (especially in the upper bass) than the set-up at the dealer, the MC20 has been more accurate than my Proceed HPA2, but doesn't suffer from being too "clinical" after 1 day of listening to music. Unfortunately, the dealer doesn't have the MC50 or MC70 for me to try out at home. The MC20 has barely gotten warm, sitting on a wooden shelf without anything above it. Of note, I believe that going from MC20 to 30 to 50 to 70, Halcro simply adds modules in the same chassis and changes the backplate and faceplate, so an MC70 might run significantly hotter than an MC20. Specs are available on Halcro's website.

If you're worried about ventilation, take a look at a company called "Cool Components".

Meridian G68XXV, Meridian G08, Panasonic Blu-Ray, Proceed HPA2/AMP3, Nautilus 802/HTM1/805, Velodyne DD-12, JVC DLA-RS1, Stewart GreyHawk RS