Appendix B: How Is Measured The Amplifier Power; General Description Of The Setup - Yamaha Nexo NXAMP4X4 User Manual

Appendix B: How is measured the amplifier power?

This part of the document describes the setup we have used to measure the power
available on the NXAMP Powered TDcontroller outputs for each load (8, 4 and 2 Ohms).

General description of the setup

The drawing bellow shows the setup used to measure the output power:
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& Kjær
NXAMP Under Test
The Audio Generator with distortion analyzer is used to generate test signals. It analyzes
the output of the amplifier to measure the THD+N, thus we can know when we reach the
clip of the amplifier with a certain value of distortion (typically 1 %).
The NXAMP under test is powered through a monitored power supply with voltage adjusted
to 230 Volts (+2/- 0 Volts) and 50 Hz.
The 4 analog inputs of the NXAMP Powered TDcontroller are linked together so all the
channels are fed. DSP setup is "FLAT – NO PROTN", meaning that no EQ or gain is applied
and that only the amplifier protections are working. The volume is set to 0 dB attenuation.
Each output of the amplifier is connected to a dummy load (8, 4 or 2 Ohms). On one
channel, we loop the voltage back to the distortion analyzer and to a digital scope, to
APPENDIX B: HOW IS MEASURED THE AMPLIFIER POWER?
Audio Generator
with
Distortion Analyzer
4x Dummy
Loads
PAGE 87 OF 91
Digital Scope