Logistical issues meant that I measured different samples of the Infigo Method 3, serial numbers 3022-0002 and 3022-0003, than those auditioned by JVS. I started the testing with sample ’0003, using my Audio Precision SYS2722 system.1 Initially, I used a balanced connection between the Audio Precision’s signal generator and the Method 3. I preconditioned the amplifier following the CEA’s recommendation, operating it at one-eighth the maximum power into 8 ohms for 30 minutes prior to testing. At the end of that time, the right-hand heatsink was warm, at 101.8°F (38.8°C), but the left-hand heatsink was at room temperature (see later).
Then I encountered problems: I saw bursts of high-frequency noise coinciding with the waveform peaks; these bursts went away when the XLR ground (pin 1) was floated. But with the ground floated, the Method 3’s frequency
