PA-7

About the PA-7

The Nakamichi PA-7 is a stereo power amplifier produced between 1987 and 1989, featuring a design licensed from Nelson Pass' Threshold Stasis technology. It delivers 200 watts per channel into 8 ohms with a frequency response of 20Hz to 20kHz and total harmonic distortion of 0.1%. The amplifier uses a highly linear, low-current Stasis voltage amplifier section combined with high-current output stages, employing sixteen high-power transistors per channel. It has a damping factor of 60, input sensitivity of 2V, and a signal-to-noise ratio of 120dB. The PA-7 is known for its robust build, including a large 700 VA toroidal power transformer and 132,000 microfarads of power-supply filter capacitance, weighing approximately 27 kg (59.5 lbs). It features heavy-duty binding posts for speaker outputs and gold-plated RCA input jacks. The amplifier runs warm during operation and is praised for its warm, neutral, and powerful sound, capable of driving demanding loudspeakers including electrostatic and Magnepan types. It has no level adjustments on the front panel, only a power switch with LED indicators for clipping. The PA-7 is considered a classic and highly desirable vintage amplifier, with a reputation for excellent sound quality and build, though professional servicing can be costly due to its age and component specifications. The PA-7II is a later variant with slightly higher power output but the original PA-7 is often preferred by enthusiasts.