So back to the topic, I have improved the options for testing audio components a bit. After making a 300W 1x2, 1x16 Ohm or 2x4, 2x8 Ohm) dummy load myself, installing a Tektronix 2465 oscilloscope, I replaced the test amplifier with a Yamaha DVD receiver and made a new patch panel. Small speakers on the sides of the connection panel will allow you to listen to the signal in artificial load mode. A rotary switch allows you to connect a test VU meter to the appropriate inputs or outputs.