SRA-120 Power Amplifier Operating Manual Level (dB) -1 0 -3 - -6 -20 - -6 -20 Sig. Clip Protect Stereo Headphones Level (dB) -1 0 -3 SRA-120 Stereo Power Amplifier -10 Channel 1 (M ono) Sig. Clip -10 SRA-120 Channel 2 Channel 2 Protect Power ASHLY AUDIO INC. 847 Holt Road Webster, NY 14580-9103 Phone: (716) 872-0010 Toll-Free: (800) 828-6308 Fax: (716) 872-0739 Internet: http://www.ashly.
Operating Manual - SRA-120 Power Amplifier Table Of Contents 2 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 AC POWER REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 AC Voltage Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Manual - SRA-120 Power Amplifier 9 DESIGN THEORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 10 TROUBLESHOOTING TIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1 No Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 Distorted Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.
Operating Manual - SRA-120 Power Amplifier 1. INTRODUCTION Congratulations on your purchase of the Ashly SRA-120 professional stereo power amplifier. This single rack-space (1 3/4" height) amplifier delivers a substantial amount of power with exceptional audio quality and many features typically found only in larger power amplifiers, Both channels of the SRA-120 can easily drive 4 ohm loads, delivering a total of 120 watts of undistorted, average sinewave power. 3. AC POWER REQUIREMENTS 3.
Operating Manual - SRA-120 Power Amplifier 4.2 Output Cables The wire gauge used for speaker cables is important, in that inadequate wire gauge adds significant resistance to the speaker’s own impedance, reducing the power which is actually delivered to the speaker. It also results in a decrease in the damping factor and possible fire hazard. 5. Since power at the speaker load is a primary concern in system design, we have included a table to best determine appropriate wire gauge for your application.
Operating Manual - SRA-120 Power Amplifier Level (dB) -3 SRA-120 Stereo Power Amplifier -1 -6 -20 - -6 -20 Sig. Clip -10 FRONT PANEL FEATURES Sig. Clip -10 Channel 1 (Mono) 6. 0 -3 - Protect Stereo Headphones Level (dB) -1 0 Channel 2 6.5 6.1 Power Switch When the unit is switched on there is a 2 second delay, during which time the PROTECT circuit will activate. The load is disconnected during this power-up sequence .
Operating Manual - SRA-120 Power Amplifier SRA-120 7. Channel 2 Protect Power REAR PANEL FEATURES Tip (+) Ring (-) Sleeve (Ground) 7.1 Inputs The input of the SRA-120 amplifier is equipped with balanced 1/4" tip-ring-sleeve (TRS) phone jacks and balanced screw-terminal inputs. Each channel's connectors are internally wired in parallel and may be used with balanced or unbalanced connections. The nominal input impedance (balanced) is 20KΩ and the maximum input level is +22dBu.
Operating Manual - SRA-120 Power Amplifier In situations where the power amp and its signal source are separated by great distances, a ground voltage difference may exist between the amp’s chassis ground and the input cable’s ground. Connection of these two grounds through the jumper strap may cause large ground currents to flow (which is known as a ground loop), causing a hum noise in the amp’s output.
Operating Manual - SRA-120 Power Amplifier 8.2 Stereo Playback Monitoring System Here the SRA-120 is fed from a low line-level (-10dBu) stereo tape machine or CD player. Only the sensitivity switch should be depressed. 8.3 Mono Operation in High Level Bi-Amped System Here the SRA-120 is fed from the high frequency output of a professional two-way crossover. The stereo/ mono and normal/bridged switches are both depressed to obtain the maximum amount of power when amplifying a mono signal.
Operating Manual - SRA-120 Power Amplifier 9. DESIGN THEORY Ashly engineers set out to design a single rack space stereo power amplifier delivering a minimum of 120 watts total with the sonic excellence, mechanical ruggedness and unsurpassed reliability Ashly amps are known for. These qualities were upheld while containing other important parameters such as weight, depth, serviceability and cost.
Operating Manual - SRA-120 Power Amplifier SRA-120. Isolate which piece of equipment in the audio chain is causing the noise. The audio source medium itself may contain the noise. • Signal present indicators active but clip LED is not: Applied input signal is distorted before it gets to the amp. Check to see if a piece of equipment in the signal chain before the amp is clipping. Normally the amplifier should be operated with input levels fully CW to maximize headroom in the signal source.
Operating Manual - SRA-120 Power Amplifier 12. SPECIFICATIONS 12.1 Output Power: 12.13 Power Requirements: 110-125VAC, 50-60Hz (240V Available) 12.14 Shipping Weight: Maximum Average Power, 0.1% THD, 1KHz RMS Watts Per Channel, Both Channels Driven 8 ohms: 4 ohms: 40W 60W 20 lbs. Specification conditions are 120VAC 60Hz at 25°C. 13. WARRANTY POLICY Bridged Mono Mode: 8 ohms: 120W FTC Continuous Power, 0.1% THD, 20Hz-20KHz RMS Watts Per Channel, Both Channels Driven 8 ohms: 4 ohms: 12.2 12.
Operating Manual - SRA-120 Power Amplifier SCHEMATICS: Figure 15.1: SRA-120 Block Diagram and Wiring Diagram. 14.
Operating Manual - SRA-120 Power Amplifier 14 Figure 15.2: SRA-120 Channel One Schematic Diagram.
Operating Manual - SRA-120 Power Amplifier Figure 15.3: SRA-120 Channel Two Schematic Diagram.
Operating Manual - SRA-120 Power Amplifier ASHLY AUDIO INC. 847 Holt Road Webster, NY 14580-9103 Phone: (716) 872-0010 Fax: (716) 872-0739 Toll Free (800) 828-6308 Internet: http://www.ashly.com 1997 by Ashly Audio Corporation. All rights reserved worldwide.