Preamp/Processors

The above chart shows the frequency response of the left (purple), center (blue), LFE (red), and left-surround (green) channels at the preamp outputs of the Dolby Digital decoder. The left, center, and surround channels are all flat, +0.01/-0.38 decibels from 20 hertz to 20 kilohertz. The LFE channel, normalized to the level at 40 Hz, is -0.15 dB at 20 Hz, reaches the upper -3dB point at 119 Hz, and reaches the upper -6dB point at 122 Hz. The analog frequency response of the left channel is -0.42 dB at 20 Hz and -0.07 dB at 20 kHz. The response dropped to -1.26 dB at 10 Hz and to -0.57 dB at 50 kHz. The analog THD+N is less than 0.040% at 1 kHz with a 100-millivolt input and the volume control set to 70. Crosstalk with a 100-mV input was -89.21 dB left to right and -90.30 dB right to left. The signal-to-noise ratio with a 100-mV input from 10 Hz to 24 kHz with "A" weighting was -95.65 dBrA.—AJ

� HT Labs Measures: McIntosh MC206 Amplifier

This graph shows that the MC206's left amplifier channel, with two channels driving 8-ohm loads, reaches 0.1% distortion at 165.3 watts and 1% distortion at 174.4 watts. Into 4 ohms, the amplifier reaches 0.1% distortion at 261.7 watts and 1% distortion at 301.6 watts. An input level of 103 millivolts was required to produce an output of 2.83 volts into an 8-ohm load, indicating an overall gain of 28.8 decibels. With all channels driven into 8-ohm loads, the amp reaches 0.1% distortion at 121.8 watts and 1% distortion at 139.0 watts. The amplifier's frequency response was +0.00/-0.21 dB from 20 Hz to 20 kHz. The response dropped to -0.68 dB at 10 Hz and to -0.57 dB at 50 kHz. THD+N from the amplifier was less than 0.007% at 1 kHz when driving 2.83 volts into an 8-ohm load. Crosstalk at 1 kHz driving 2.83 volts into an 8-ohm load was -86.53 dB left to right and -87.51 dB right to left. The signal-to-noise ratio with 2.83 volts driving an 8-ohm load from 10 Hz to 24 kHz with "A" weighting was -103.06 dBrA.—AJ