Welcome, Rogel. In case Mark(BigWill)doesn't see your question(starting a new thread is usually better),I'll offer my thoughts. His 2802 is rated at the same 90 watts as your 1804 and you should have plenty of power for your speakers unless your listening room is huge. Once amps get up near the 100 watt area, that's generally fine. For example, the difference in maximum sound level between 90 watts and 120 watts is only about 1.2dB(e.g.110dB or 111.2dB). M60s use about 1 watt at a comfortably loud listening level, and of course much more on split-second peaks, possibly 100 watts or more, which the 1804 should handle with ease. All amps operating within their power capacity with flat frequency response and inaudibly low noise and distortion(which is common these days)are transparent and there's no "sound" to be concerned about.
