7

About the 7

The Jeff Rowland Model 7 is a monophonic solid-state power amplifier designed for audiophiles seeking both power and finesse. It delivers 350 watts RMS continuous into 8 ohms, 700 watts into 4 ohms, and 1100 watts into 2 ohms, with a wide power bandwidth from 0.15 Hz to 175 kHz (-3 dB). The amplifier features a unique design with no overall or nested negative feedback to eliminate time domain distortion, proprietary distortion canceling techniques, and individually tested and matched transistors for optimal performance. It uses a single voltage amplification stage with field effect transistors operating in transconductance mode to enhance low-level signal recognition. The signal path is free of capacitors, inductors, fuses, and protection circuitry to avoid their adverse effects. A large toroidal power transformer supports the substantial output stage, and all critical circuitry is encapsulated in thermally conductive epoxy for thermal stability and mechanical integrity. The amplifier has a slew rate of 50 V/µs, very low total harmonic distortion (less than 0.015% at 20 watts), and a high damping factor (>300 from 20 Hz to 20 kHz). Input impedance is selectable among 100k, 20k, and 600 ohms, and the overall gain is 26.4 dB. The Model 7 is recognized for its rich, warm, and musical tonal character with firm low-frequency control and a silky midrange, capable of driving demanding speaker loads without fatigue. Dimensions are approximately 19" (480 mm) wide, 8.75" (220 mm) high, and 24" (610 mm) deep. Originally