RX-V4600 Power Measurements and Analysis - Part 2

Test Notes:

• All amplifier power references were conducted under load and compared to open circuit voltages to determine output impedance as per our Basic Amplifier Measurement Techniques Guidelines.
• All max power tests represent 0.1% THD at 1kHz as a reference
• Distortion at 20Hz and 20kHz was also checked to ensure THD was always under 1%
• Line Voltage was monitored to ensure no sag was present (115Vrms recorded)
• Reference 1 watt = 2.82Vrms into an 8ohm load

The output impedance of the RX-V4600 was commendably low for a single pair transistor push-pull amplifier stage. It also appeared to be more uniform than what we have seen in the RX-V2500 indicating that the series output inductor after the last output stage to increase stability may have been eliminated or its value reduced.

Damping factor remained stable and uniform at into an 8-ohm and 4-ohm load. Based on the principle of voltage divider, we see roughly a little less than ½ the damping factor for the 4-ohm load. Ideally it would have been exactly ½, but this is certainly better performance than we have seen with the RX-V2500. The damping factor remained close to our minimum recommendation of 50. For more information on this topic, read our article on Damping Factor: Effects on System Response .

Amplifier output impedance and damping factor at full power (128wpc 8-ohms, 200wpc 4-ohms; respectively) remained highly linear. The RX-V4600 excelled on this test in comparison to the RX-V2500.