DISCO 70 80 90 | ADCOM GFA 5500 Made in USA | Complete Disassemble, Clean, Inspect, and Reassemble

ADCOM GFA 5500 Power Amplifier | Made in USA | Designed by Nelson Pass | Complete Disassemble, Clean, Inspect, and Reassemble BIAS ALIGNMENT Prior to performing BIAS ALIGNMENT turn unit on and allow to idle for approximately 5 MINUTES before attempting adjustments. 1. Connect millivoltmeter across emitter resistor R52 for left channel (R51 for right channel) 2. Adjust bias pot P2 until meter reads 50mV +/- 5mV DC OFFSET ADJUSTMENT 1. Connect millivoltmeter across speaker output 2. Adjust DC offset pot P1 until meter reads 0mV +/- 10mV GFA-5500 SPECIFICATIONS Power Rating (To FTC Requirements) 200 watts continuous average power per channel into 8 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0.18% THD 350 watts continuous average power per channel into 4 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0.18% THD IM Distortion (SMPTE) 1 watt to 200 watts into 8 ohms...............................................................................................0.05% 1 watt to 350 watts into 4 ohms.............................................................................................. 0.05% IM Distortion (CCIF, Any Combination from 4kHz to 20kHz) 200 watts into 8 ohms...............................................................................................................0.04% 350 watts into 4 ohms.............................................................................................................. 0.04% THD + Noise at 200 watts into 8 ohms (Typical) 20Hz.................. 0.018% 1kHz................... 0.02% 10kHz..................0.07% 20kHz..................0.13% THD + Noise at 350 watts into 4 ohms (Typical) 20Hz.................... 0.018% 1kHz.....................0.02% 10kHz.................. 0.08% 20kHz.................. 0.16% Frequency Response @ 1 Watt into 8 ohms (10Hz to 20kHz)...............+0, -0.25dB Power Bandwidth (-3dB) ......................................................................... 3Hz to 130kHz Dynamic Headroom into 4 ohms............................................................. 1.7 dB Signal to Noise Ratio, “A” Weighted (200 watts into 8 ohms) ............... 100dB Gain............................................................................................................ 29dB Input Sensitivity for 1 Watt.................................................................................................... 0.1 volts for 200 Watts ............................................................................................. 1.4 volts Input Impedance........................................................................................ 49.9kW Damping Factor (20Hz to 20kHz).............................................................. 700 Rise Time (5kHz, 90V, peak-to-peak square wave, 20% to 80%)................5mS Power Consumption (Continuous, All Channels Driven) Quiescent ............................................................. 199VA Maximum .............................................................. 855VA 80 watts into 8 ohms............................................ 1440VA 125 watts into 4 ohms.......................................... 720VA Power (Available in 230VAC on special order)....115VAC - 50/60Hz Chassis Dimensions ........................................... 7” (178mm) x 17” (432mm) x 13 3/4” (349mm) Maximum Dimensions ....................................... 7 1/4” (184mm) x 17” (432mm) x 14 3/4” (375mm) Weight.................................................................. 44 lb. (25.9 kg) Weight, Packed.................................................... 50 lb. (28.6 kg)