PA-7

About the PA-7

The Nakamichi PA-7 is a stereo Stasis power amplifier produced in the late 1980s (circa 1987-1989), using technology licensed from Nelson Pass's Threshold Stasis designs. It is factory-rated at 200 watts per channel into 8 ohms with a frequency response of 20 Hz-20 kHz, total harmonic distortion of 0.1%, damping factor 60, input sensitivity 2V, and signal-to-noise ratio 120 dB, employing sixteen high-power output transistors per channel. The PA-7 uses a highly linear, low-power Stasis voltage amplifier section coupled to high-current output stages, providing substantial current delivery and allowing it to drive demanding loudspeakers, including low-impedance and planar designs, with excellent control. The amplifier is built around a large toroidal power transformer and substantial power-supply capacitance (approximately 132,000 uF), contributing to its strong dynamics and stability under load. It weighs about 27 kg and features a minimalist front panel with only a power switch and status/clip indicators, while the rear panel provides gold-plated RCA input jacks and heavy-duty binding posts. Due to its age and design complexity, professional servicing may be advisable. A later variant, the PA-7II, offers a slightly higher rated output of around 225W per channel into 8 ohms.