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 substan- tial amount of power with exceptional audio quality and many features typically found only in larger power am- plifiers,
Both channels of the SRA-120 can easily drive 4 ohm loads, delivering a total of 120 watts of undistorted, average sinewave power.
The amplifier has an automatic output turn-on delay and instantaneous output turn-off to protect speak- ers from transients. Each output will also turn off if it "sees" a load of 2 ohms down to a short circuit. The out- puts are also independently protected from overheat con- ditions. Each channel will automatically reset itself from any of these protection modes independent of the other channel's operation.
The SRA-120 provides front panel level controls, a stereo headphone jack, and six status LED's for ease of control and monitoring. The back panel provides both balanced 1/4" jacks and balanced screw terminal inputs. Three push-button switches allow selection of stereo, mono, bridged mode, and input sensitivity, allowing the amplifier to be applied in any configuration. The amplifier's signal ground can also be lifted from chassis ground via a barrier strip jumper.
2.UNPACKING
As a part of our system of quality control, every Ashly product is carefully inspected before leaving the factory to ensure flawless appearance. After unpacking, please inspect for any physical damage. Save the ship- ping carton and all packing materials, as they were care- fully designed to reduce to minimum the possibility of transportation damage should the unit again require pack- ing and shipping. In the event that damage has occurred, immediately notify your dealer so that a written claim to cover the damages can be initiated.
The right to any claim against a public carrier can be forfeited if the carrier is not notified promptly and if the shipping carton and packing materials are not avail- able for inspection by the carrier. Save all packing mate- rials until the claim has been settled.
3.AC POWER REQUIREMENTS
3.1Voltage Requirements
Your SRA-120 amplifier is supplied with a three conductor grounded AC power cord, and should be plugged into a standard 3-wire grounded electrical outlet which supplies 120VAC 50-60 Hz (some export models are wired for 100 or 240 volts and are labeled as such). In the event of line voltage sag, or “brown-out”, SRA- 120 amplifiers will continue to operate normally, albeit with less power.
3.2Current Requirements
The actual AC current consumption by the am- plifier depends greatly on the audio signal and the load impedance. For typical audio program material with the SRA-120 driving both channels just peaking at the clip- ping level, the following AC line current is drawn and should be used for system design purposes:
Idle | 0.1A |
8Ω loads | 0.6 Amps |
4Ω loads | 1.0 Amps |
Table 3.1: Estimated Maximum RMS AC Line Current Draw
3.3AC Grounding Requirements
To reduce the risk of ground loop hum, all sys- tem ground references should originate at the same point in your AC power distribution . Never remove the amplifier’s ground pin as it is both unlawful and danger- ous, creating a potential shock hazard.
4.CABLE REQUIREMENTS
4.1Input Cables
Be sure to use shielded cable whether balanced or unbalanced. Shielding which is properly grounded will protect the signal from outside electrical interference such as RF, fluorescent lighting, even computer noise. As a general rule, unbalanced or single-ended (tip-sleeve) lines of less than 10 feet are satisfactory, but greater distances may require a balanced signal. Avoid running input lines in close proximity or parallel to long speaker lines, AC power cables, or power transformers, as this may gener- ate hum or oscillation.
