Parasound A 21 - Manuals

XLR Connectors Male Female YOU SHOULD KNOWBalanced XLR Jacks and Their Pin Configuration The balanced inputs of the A 21 use XLR jacks that conform to the industry standard of: Pin 1: Ground, Pin 2: Positive (+), Pin 3: Negative (--). The balanced outputs on some components use terminals with 3 scre...

Left and Right Unbalanced Inputs Use these inputs if your preamplifier or surround controller doesn’t have balanced output connectors or if you simply prefer to use unbalanced connections. What You’ll Need: • A pair of shielded interconnect cables with RCA plugs • A source component with RCA output ...

Loop Out Connector The Right and Left Loop Out jacks provide connections to route the same input signals from your preamplifier or surround controller to an additional power amplifier. In most instances, you won't use the loop out feature so you can skip this section. What You’ll Need: • One pair of...

Stripped AWG wire Dual Banana Plug Common Speaker Connectors Single Banana Plug Spade Lug Red usually designates right The GND notch signifies ground or speaker left Speaker Terminals The five-way binding post speaker terminals on the A 21 accept most speaker wire terminations including single or du...

CONFIGURING THE A 21 FOR BRIDGED MONO OPERATION 6 YOU SHOULD KNOW IMPORTANT! - Before Trying Bridged Mono You should not connect a speaker with an impedance of less than 8 Ω to the A 21 when it is configured for bridged mono operation. Refer to Bridged Mono Operation in the Technically Speaking sect...

MANUAL AND AUTOMATIC TURN ON-OFF OPTIONS 7 YOU SHOULD KNOWTurn Off Delay in the Audio Mode When the music (audio signal) stops, the A 21 will remain turned on for about five minutes. This delay prevents unwanted turn-off during silent passages in music or pauses between 1 Switch in up position Start...

CONNECTING AN EXTERNAL DC SOURCE FOR A 21 AUTOMATIC TURN ON-OFF 8 1 2 YOU SHOULD KNOW If the device you want to use to control your A 21 doesn’t have a 2.5 mm trigger output connector, you can cut one plug off the cable and terminate the end as required. The lead with the red stripe is positive and ...

B CONNECTING THE A 21 TO TRIGGER ANOTHER COMPONENT 9 1 2 YOU SHOULD KNOW If the device you want your A 21 to control doesn’t have a 2.5 mm trigger output connector, you can cut one plug off the cable and terminate the end as required. The lead with the stripe is positive and the lead without the str...

UNDERSTANDING THE INDICATORS ON THE A 21 AC Present Indication When the A 21 is plugged into a live AC outlet, a soft blue halo glows behind its On-Off button and its red “P” Badge glows faintly. These indicate that the unit is plugged into a live AC outlet, even when it is turned off. On, Off and F...

AC Power Connections We recommend that you plug your A 21 into the same AC wall outlet or power strip that powers your other audio components, especially the preamplifier or system controller. Having all the audio components on the same power circuit helps prevent hum caused by possible ground loops...

MAINTAINING YOUR A 21 Your Parasound A 21 power amplifier requires no periodic maintenance and has no user-serviceable parts inside. To avoid the risk of electric shock, do not remove its top cover. The amplifier’s exterior can easily be cleaned with a soft cloth pre-moistened only with a few drops ...

TROUBLESHOOTING GUIDE 13 A 21 will not turn off when audio signal is removed PROBABLE CAUSE Power cord is disconnected REMEDY Hum and / or buzz through speakers Ground loop between preamplifier and A 21 or at the equipment rack Move the Ground switch to its Lift position Install nylon shoulder washe...

SERVICING YOUR A 21 14 If All Else Fails –Call Us for Help Call your Parasound dealer or Parasound’s Technical Service Department toll free at 1-866-770-TECH (8324). We can often solve the problem with simple diagnostic tests you can perform yourself. If we determine that your A 21 will need further...

Audio Trigger Sensitivity Adjustment The Audio Sensitivity Control sets the threshold of the audio trigger signal. You can adjust this level from a maximum sensitivity of 50 mV (fully counterclockwise) to a minimum sensitivity of 200 mV (fully clockwise). If you set this control to 50 mV, the A 21 m...

TECHNICALLY SPEAKING continued 16 Choosing Interconnect Cables and Speaker Wire We are often asked to recommend specific interconnect cables and speaker wire. It’s true that with some amplifiers, sound quality will vary greatly according to interconnect cables and speaker wires. However, Parasound a...

PARASOUND A 21 DESIGN OVERVIEW 17 chosen for their low Equivalent Series Resistance (ESR) and dielectric absorption. In addition, these filter capacitors are bypassed with smaller polypropylene capacitors to reduce AC ripple in the DC supply and to further eliminate noise and interference that is ge...

PARASOUND A 21 DESIGN OVERVIEW continued 18 Total Protection - DC Servos Direct Current (DC) burns out speakers. Every power amplifier must have some way to insure that DC from its power supply never reaches its + or - speaker terminals. Most amplifiers simply use trim controls to reduce their DC of...

Power Output - Both Channels Driven 250 watts RMS x 2, continuous, 20 Hz - 20 kHz, 8 Ω 400 watts RMS x 2, continuous, 20 Hz - 20 kHz, 4 Ω Power Output - Mono 750 watts RMS, 20 Hz - 20 kHz, 8 Ω Current Capacity 60 amperes peak per channel Slew Rate > 130 volts per microsecond Frequency Response 5 ...