Parasound A 51 manual

A 5 1 Amplif ier Owner’ s Guide[...]

Congratulations and Thank Y ou for Choosing Parasound Y our new P arasound Halo Series A 51 pow er amplifier presents the latest advancements in amplifier tec hnology . The A 51 is built to the strict qualit y and performance standards set by P arasound. W e’ re proud to of f er you this e xceptional audio component that will bring y ou many y ea[...]

T ABLE OF CONTENTS A 51 Amplifier PLACEMENT GUIDELINES FOR YOUR A 51 2 CONNECTING A SURROUND CONTROLLER TO THE BALANCED INPUTS ON YOUR A 51 3 CONNECTING A SURROUND CONTROLLER TO THE UNBALANCED INPUTS ON YOUR A 51 4 CONNECTING YOUR SPEAKERS TO THE A 51 5 MANUAL AND AUTOMA TIC TURN ON-OFF OPTIONS 6 CONNECTING AN EXTERNAL DC SOURCE FOR AUTOMA TIC ON-O[...]

PLACEMENT GUIDELINES FOR YOUR A 51 Power amplifiers are usually heavier and generate more heat than other components. T o avoid damage to the A 51 or other equipment and to reduce risk of fire, you must follow these guidelines: • A cable with a 2.5 mm sub-mini plug on eac h end (provided). • Place the A 51 on a separate shelf that will adequate[...]

CONNECTING A SURROUND CONTROLLER TO THE BALANCED INPUTS ON YOUR A 51 Left and Right Balanced Input Jacks Balanced connections will giv e you the best sound. If y our surround controller has balanced XLR output jac ks, we recommend that you connect them to these inputs. R ef er to the Balanced and Unbalanced Lines in the T ec hnically Speaking secti[...]

CONNECTING A SURROUND CONTROLLER TO THE UNBALANCED INPUTS ON YOUR A 51 Ch 1-5 Unbalanced Inputs Use these inputs if your sur round controller doesn ’ t ha ve balanced output connectors or if y ou simply pref er to use unbalanced connections. What Y ou ’ ll Need: • Five shielded interconnect cables with R CA plugs • A surround controller wit[...]

CONNECTING YOUR SPEAKERS TO THE A 51 Speaker T erminals The A 51 speaker terminals accept speak er wires with banana plugs or bare ends. Ref er to Bare W ire Speaker T ermination in the T echnically Speaking section f or information about bare wire termination. What Y ou ’ ll Need: • Five lengths of A WG 1 6 or thic ker speaker wire with banana[...]

MANUAL AND AUTOMA TIC TURN ON-OFF OPTIONS Y ou can manually turn the A 51 on and off with its front panel On-Off button. It can also be triggered to turn on and off automatically when your preamplifier , surround controller , or system controller is turned on and off. Manual On-Off from the Front Panel If you w ant to manually turn on and of f the [...]

CONNECTING AN EXTERNAL DC SOURCE FOR AUTOMA TIC TURN ON-OFF T o automatically turn on and off the A 51 with an external DC voltage, choose the DC T riggering option by moving the Auto T urn On switch on the rear panel to its lower 1 2 V position. What Y ou ’ ll Need: • A cable with a 2.5 mm sub-mini plug on eac h end (provided) • A “ contro[...]

UNDERST ANDING THE INDICA TORS ON THE A 51 a AC Present Indication When the A 51 is plugged into a liv e A C outlet, a sof t blue halo glows behind its On-Of f but ton and its red “ P ” Badge glo ws faintly . These indicate that the unit is plugged into a liv e A C outlet, even when it is t urned off . b On, Off and Fault/Protection Status Indi[...]

CONNECTING THE A 51 AC POWER CORD AC Power Connections W e recommend that you plug y our A 51 into the same A C wall outlet or pow er strip that pow- ers your other audio components, especially the preamplifier or sy stem controller . Having all the audio components on the same pow er circuit helps prev ent hum caused by possible ground loops. The [...]

MAINT AINING YOUR A 51 Y our Parasound A 51 power amplifier requires no periodic maintenance and has no user - serviceable parts inside. T o 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 of water or glass cleaner . Main Power F[...]

TROUBLESHOOTING GUIDE 11 No pow er Auto turn on doesn’ t function with a trigger voltage Auto turn on doesn’ t function with an audio input signal A 51 will not turn of f when audio signal is remov ed P ow er on, but no sound On-Of f but ton glows red and c hannel indicator(s) of f Distorted sound Hum and / or buzz through speak ers A 51 is ov [...]

SERVICING YOUR A 51 If All Else Fails – Call Us for Help Call your P arasound dealer or Parasound ’ s T ec hnical Ser vice Department toll free at 1 -866-770-TECH (8324). W e can of ten solve the problem with simple diagnostic tests y ou can per- form y ourself . If we determine that your A 51 will need further inspection or ser vicing, we will[...]

TECHNICALL Y SPEAKING 13 Audio T rigger Sensitivity Adjustment The Audio Sensitivity Control sets the threshold of the audio trigger signal. Y ou can adjust this lev el from a maximum sensitivity of 50 mV (fully countercloc kwise) to a minimum sensitivity of 250 mV (fully cloc kwise). If you set this control to 50 mV , the A 51 might be falsely tri[...]

TECHNICALL Y SPEAKING continued 14 hum (or 50 Hz hum in regions with 50 Hz A C). T he harmonics of these frequencies (1 20 Hz, 240 Hz, 480 Hz or 1 00 Hz, 20 0 Hz, 400 Hz) may add buzz in addi- tion to the hum. The ideal of z ero voltage ground for all the compo- nents in a system is practically impossible, because some resistance bet w een the grou[...]

P ARASOUND A 51 DESIGN OVERVIEW 15 Circuit Designed by John Curl P arasound design consult ant J ohn Curl has been a legend among audiophiles and electronic engineers for decades. He pioneered measurements to cor re- late musical accuracy with the materials used in parts, work ed with world-class touring companies, has designed highly cov eted audi[...]

P ARASOUND A 51 DESIGN OVERVIEW continued 16 The Driver Stage The driv er stage provides critical amplification for whic h we emplo y a complementar y matc hed pair of MOSFETs selected f or their tube-lik e sonic qualities. MOSFETs tend to generate less odd-order harmonic distortion than bipolar transistors. T his is import ant because odd-order di[...]

P ARASOUND A 51 SPECIFICA TIONS Power Output - All Channels Driven 250 wat ts RMS x 5, continuous, 20 Hz - 20 kHz, 8 Ω 400 wat ts RMS x 5, continuous, 20 Hz - 20 kHz, 4 Ω Current Capacity 60 amperes peak per c hannel Slew Rate > 1 30 volts per microsecond Frequency Response 5 Hz - 1 0 0 kHz, +0/-3 dB at 1 wat t T otal Harmonic Distortion <[...]

Parasound Pr oducts, Inc. 950 Batter y Str eet, San Francisco , CA 94111 415-397-7100 / Fax 415-397-0144 www .parasound.com[...]