Audio research Classic 60 - Triode
Description: stereo, hybrid tube/FET power amplifier. Tube complement: four matched pairs of low-gas 6550s, four 6FQ7/6CG7s. Maximum power output: at least 60W into 16 ohms (20.8dBW), 15Hz-20kHz, with less than 1% THD; typically 62W at 1kHz with 120V AC line. Power bandwidth (-3dB): 12Hz-40kHz. Input sensitivity: 550mV RMS for rated output. Input impedance: 100k ohms. Output regulation: approximately 0.3dB, 16 ohms to open circuit (equivalent to an output impedance of 0.56 ohmsdamping factor quoted as approximately 30). Negative feedback: 20dB. Slew rate: 20V/µs. Risetime: 2µs. Hum and noise: less than 2mV RMS84dB below rated output (20kHz bandwidth, unweighted, input shorted). Power supply energy storage: approximately 280 joules. Power requirements: 500W at rated output, 700W maximum, 370W at idle.