Power Amplifiers

Earthquake Sound Cinenova 7 Multi-Channel Power Amplifier

ARTICLE INDEX

On the Bench

Distortion measurements were made within an 80 kHz bandwidth. One of my Carver Mark IV speakers was used as the load, except where indicated. I ran the tests using a single module, since each module is independent.

At 10 volts output, THD+N was 0.02%. Even-ordered harmonics predominated.

cinenova-7-1-khz

Using 19 kHz and 20 kHz sine waves, the B-A peak at 1 kHz was 70 dB below the fundamentals.

cinenova-7-19-khz-20-khz

IMD was 0.03%, using 60 Hz and 7 kHz sine waves as the test signals.

cinenova-7-imd

THD+N vs. Frequency was flat out to about 4 kHz, then rose to a bit more than 0.1% at 8 kHz to 50 kHz.

cinenova-7-thd-plus-n-vs-fr

Here is an impedance/phase plot for the Carver Mark IV speaker that I used as a load for some of the bench tests.

carver-amazing-mark-4-speaker-impedance-phase

The measured frequency response was 10 Hz - 20 kHz, - 0.1 dB, and was down 5 dB at 100 kHz.

cinenova-7-fr

Output into 8 ohms indicated the sharp knee at 150 watts, with clipping (1% THD+N) at 170 watts.

cinenova-7-power-output-8-ohms

Using a 4 ohm load, output showed the sharp knee at 230 watts, and clipping at 280 watts. I did not test the amplifier into a 2 ohm load.

cinenova-7-power-output-4-ohms