Crown Audio CTs-600 CTs Series 2-Channel 300 Watt per Channel Amplifier, 8/4/2 Ohm or 70/140V

could not use the product

Although the CTs series is intended for professional fixed installations, I am using this one in a home consumer two-channel audio system and these review comments reflect my usage there. In spite of this "mis-application", I like the sound of the unit and have yet to come anywhere near to exploring its power limits. I purchased the CTs based on previous experience with Crown, especially the ComTech 200 amplifier. Crown states that the CTs is based on the design principles of the old ComTech line. One big change is that the CTs employs a switching power supply which provides 3x the rated audio output power while reducing the weight of the unit.The home audio environment provides two main challenges for the CTs: the input connectors and the cooling fans. The input connectors are basically three screw-heads per channel (balanced inputs), though mediated by the included small Phoenix connectors. These connectors (one per channel) contain the screw-heads and themselves plug into three-pin headers arranged on the amplifier's input board. This particular challenge is easily addressed by making up your own input cables, as I did.The other main challenge will be the cooling fans. At my listening levels for classical music, it takes 30-45 minutes for the fans to first kick on, and then they run fast and loud for a few minutes to exhaust the heat buildup. Following that, the fans calm down to a moderate level where they seem to stabilize indefinitely. The audible noise at this level is covered up by average musical program content but will be evident in silent passages or during speech and similar material with gaps. Strict audiophiles would not accept this level of audible background noise and I wouldn't recommend the CTs in that case. Fan "mods" are possible (in a home consumer environment only) but I'm holding off on that at least through the warranty period.In summary, this is a Made-in-USA bullet-proof amplifier with audiophile sound, at an excellent price for the output power/performance. For home consumer use, the compromise will be some hook-up convenience and the fan noise as noted above.*** Update on 18-Mar-2015 ***The fan noise was the only downside to the amp in my home listening environment, so I finally decided to go ahead with a "fan mod". This was enabled by my discovery of the Noctua NF-A8 ULN Premium 80mm Fan (on amazon) which is carefully designed and manufactured to minimize air movement and bearing noise. The other key part is the 7812 12v DC voltage regulator (also on amazon but I got mine locally), one for each fan since the original fans are 24v.Listening to music since the modification, from my listening position across the room the fans are only just perceptible as a very faint whisper and then only noticeable in the quiet of the late evening (and with zero input signal of course). Obviously, you would only undertake such a modification of this expensive, beautifully assembled amplifier if you are (1) strongly motivated by audiophile aspirations, (2) very handy with electronics (e.g. training, DIY, or kit-building experience), (3) willing to void any remaining warranty, and (4) plan to operate the amp only in a normal home stereo.However, having taken the plunge, and after several evenings of fan-noise-free listening pleasure, it does seem that I've now got on my hands a home stereo amplifier for the ages, at a relatively affordable price.