This units was serviced by our tech and cosmetics are 8/10, wood sleeve has light wear to back corners.
You’ll notice the ‘Twin Powered’ tag line under the 630 on the faceplate. This refers to the fact that the 630 has separate power supplies for each channel. Why? Well, with solid-state designs, closely regulated supply voltages pave the way for a cleaner and more transparent sound reproduction. A crucial aspect of any amplifier is its power supply’s ability to respond swiftly to sudden tone bursts in the music and effortlessly drive heavy and sustained passages. Equally important is the power supply’s ability to instantaneously recover from these surges, swiftly restoring its voltage level in preparation for the next peak in loudness. The Harman-Kardon 630 takes these requirements to heart, employing two separate power supplies – one for each channel – to ensure flawless performance, regardless of the amplifier’s power output demands. By providing each channel with its own regulated voltages, the 630 eliminates cross-channel interference, allowing each channel to deliver its full RMS power output without compromise. Furthermore, the recovery time of the 630 is virtually instantaneous, ensuring uninterrupted and dynamic audio reproduction.
The Harman Kardon 630 claims a guaranteed power specification of 30 watts, RMS, per channel when both channels are driven simultaneously into 8-ohm loads. With distortion (THD) guaranteed to be less than 0.5% from 20Hz to 20kHz at full RMS output, the 630 adheres to stringent and conservative measurements, similar to those employed for HK’s legendary Citation amplifier. It’s worth noting that if the 630 were evaluated using the measuring methods employed by its competitors at the time, its power rating would likely be rated at 45 watts per channel.
