After snooping around inside the Mosconi, I was more than ready to have a listen to it. Judging by the components and the construction I’d seen inside, I expected the amp to have plenty of power. I ran the front channels to my component speakers, and the rear channels were bridged to my reference subwoofer system. I set the subwoofer crossover at 80Hz, and used a matching frequency in high pass for the components. I was in the mood for some up tempo well played tunes with wide dynamic range and a very wide frequency range, so I broke out my Sheffield Labs copy of “The Usual Suspects”, and then a couple of big band tracks from Count Basie and Tommy Dorsey on a DMP recording. The Mosconi amplifier did indeed have an abundance of power, but the really cool thing was the amplifiers ability to reproduce the dynamics in these difficult tracks. Large orchestras have the ability to reach very high SPL levels, and for a stereo system to have a lifelike sound, it needs to be able to reproduce these rapid shifts in overall sound level. If an amp has poor signal to noise, the quiet passages can be obscured by hiss. If the amp has limited power, it will clip before the full volume of the recording is reached. With the Mosconi AS200.4, I had none of those issues. The amp would go from whisper soft to very loud and back to whisper soft, with an almost effortless grace. Bass notes were warm and controlled, and the highest frequencies came through with excellent clarity and detail. When the music stopped, the amp had zero audible noise. On Robbie Robertson’s almost spooky “Somewhere Down the Crazy River”, the natural reverberance in the recording came through so well I actually looked around to see where the sounds came from. Yes, the AS200.4 is a pretty good sounding amp!
As you’d expect, on the test bench the AS200.4 fared well, generally meeting the published specs to as close as makes no difference, and universally testing the way a quality amplifier should. Signal to noise measured very good for a large four channel amp, as did frequency response and stereo separation. I tested the reliability of the Mosconi, by running it at only 9 volts, dead shorting it, thermally overheating it, and through it all, it simply protected itself when it should, recovered automatically, and kept on playing. Reliability should be excellent with this amplifier. Overall power efficiency is not a strong point of any Class AB amplifier, and here the Mosconi is no different, with only average efficiency scores. But when an amp with this much power sounds this good, it’s a bit like worrying over the fuel economy of your Ferrari.
The Mosconi AS200.4 is a quality product in every regard. It’s well built, and obviously designed by people who understand what it takes to build a good sounding amplifier. The preamp section provides excellent flexibility in system design, and the amp is built with ruggedness and reliability in mind. I’m told the Mosconi amplifiers are used in world championship winning sound quality cars, and after auditioning it here, I’m not surprised. Sure there are cheaper amps, but remember, there’s a reason a Ferrari costs more than a Ford.