Stereophile has been posted review on Infigo Method-3 integrated amp.

https://www.stereophile.com/content/infigo-method-3-monoblock-power-amplifier

Price: $55,000/pair. Class-A sliding-bias monoblock power amplifier. Inputs: single-ended on XLR jack. Outputs: 2 pair binding posts. Power output: 250Wpc into 4 ohms (21dBW). Frequency response: 10Hz–100kHz, ±0.3dB. Sensitivity: 1.6V RMS for maximum output. Input impedance: 10k ohms

https://www.stereophile.com/content/infigo-method-3-monoblock-power-amplifier-measurements
It appears that all four samples of Infigo's Method 3 amplifier had a manufacturing defect that disabled class-A operation.

https://www.stereophile.com/content/infigo-method-3-monoblock-power-amplifier-manufacturers-comment
Typically, this anomaly plays an inaudible role, which is why it wasn't noted in previous listening sessions, especially at audio shows. The deepening of this cross-after current drop with increasing signal current limits the output power at higher currents, which partly explains the discrepancies in measured power between 8 ohm and 4 ohm loads. Thanks to John's input, we are incorporating a redesign of the topology of the bias circuit that is free of this anomaly and will fix the measurement discrepancies.

https://infigoaudio.com/page/method-3/