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THANK YOU!

Congratulations and Thank You for Choosing Parasound

    

Your new Parasound Halo Series A 21 power amplifier presents the latest advancements 

    

in amplifier technology. The A 21 is built to the strict quality and performance standards 

    

set by Parasound. We’re proud to offer you this exceptional audio component that will

    

bring you many years of enjoyment and dependability.

    

Here  at  Parasound,  we  design  our  products  to  perform  at  a  higher  level  of  flexibility 

    

and  sonic  performance  than  you  may  have  expected.  We  encourage  you  to  read 

    

this  entire  manual  to  learn  all  the  features  and  capabilities  of  your  new  Halo  Series 

    

A 21 Amplifier.

    

If you’re eager to get up and running right away, simply follow the basic step-by-step 

    

instructions to connect and operate the A 21. If you want to learn about some of the 

   

technical and design aspects of your A 21, refer to the 

Technically Speaking 

and 

   

Parasound A 21 Design Overview 

sections in the back of the manual. If you run into 

   

difficulties, the 

Troubleshooting Guide 

should help you quickly remedy the problem.

    

We  appreciate  you  taking  the  time  to  read  these  instructions  and  thank  you  for 

    

selecting Parasound for your listening pleasure.   

    

    

 

 

 

 

 

 

 

 

    

 

 

 

 

 

 

 

 

 

    

 

 

 

 

 

 

 

 

The Parasound Staff

Unpacking Your A 21

Unpack  your  A  21  from  the  shipping  carton,  remove  the  enclosed  rack  mounts,  AC 

power  cord,  and  the  control  wire  with  2.5  mm  sub-mini  plugs  on  each  end.  (This  is 

the  trigger  connection  wire).  While  you  are  unpacking  your  new  amplifier,  inspect 

it  thoroughly  for  possible  shipping  damage.  If  you  see  any,  contact  your  Parasound 

dealer right away. Be sure to save and store both the inner and outer cartons and the 

packing inserts for possible future transport. To save room for storage, you can cut the 

seams on the bottom of the cartons and flatten them.

Keeping Records for Future Reference

 

Record the serial number located on the bottom of your A 21 in the space below. Also 

 

note your Parasound Dealer’s name and phone number. We recommend that you keep 

 

your purchase receipt with this manual and store them both in a safe place. You may 

 

need to refer to this information sometime in the future.

 

Parasound A 21 Amplifier Serial #: ____________________

 

 

Parasound Dealer: ____________________________________ 

 

 

 

 

 

 

 

 

 

Phone Number:_______________________________________

 

 

Date of Purchase: _____________________________________

YOU SHOULD KNOW

There  is  no  Parasound  warranty  for  this  unit  if  it  was  not  purchased  from  an  Authorized 

Parasound  Dealer.  Investigate  any  warranty  claims  made  by  unauthorized  dealers  very 

carefully  as  you  will  need  to  depend  entirely  upon  the  dealer,  and  NOT  upon  Parasound. 

Unauthorized  dealers  may  lack  the  capability  to  arrange  repairs  of  Parasound  equipment. 

Authorized Parasound Dealers are listed at www.parasound.com or you can call 415-397-7100 

between 8:30 am and 4:30 pm Pacific time.

A missing or tampered serial number could indicate that this unit was stolen or sold by an 

unauthorized  dealer.  If  this  unit  is  missing  its  serial  number,  you  should  return  it  to  your 

dealer immediately for a full refund.

Содержание Halo A 21

Страница 1: ...A 21 Amplifier Owner s Guide...

Страница 2: ...u are unpacking your new amplifier inspect it thoroughly for possible shipping damage If you see any contact your Parasound dealer right away Be sure to save and store both the inner and outer cartons...

Страница 3: ...NAL DC SOURCE FOR A 21 AUTOMATIC TURN ON OFF _________________________________________________________________________________ CONNECTING THE A 21 TO TRIGGER ANOTHER COMPONENT ________________________...

Страница 4: ...rackets provided With its four feet removed the A 21 chassis and front panel height occupies four rack spaces 7 or 176 mm When mounting equipment below the A 21 you will also need to allow about 1 8 b...

Страница 5: ...that you connect them to these inputs Refer to the Balanced and Unbalanced Lines in the Technically Speaking section for additional information about why we recommend using balanced lines What You ll...

Страница 6: ...e Ground switch is in its Normal down position To Connect Plug one end of the cable into the Unbalanced Right Channel Input jack on the A 21 Plug the other end of this cable into the unbalanced right...

Страница 7: ...ed or stretched once they are connected To Connect Plug one end of the cable to the right channel Loop Out jack on the A 21 Plug the other end of this cable to the right channel input jack on the othe...

Страница 8: ...lack Right negative speaker terminal on the A 21 Insert the other end of the wire with the ridge or other marking into the red right positive terminal on the speaker Insert the wire without the ridge...

Страница 9: ...th an impedance of 8 or higher Before Connecting Remove power to all the components in your audio system Set the A 21 Stereo Mono Bridge Switch to its Mono up position To Connect From the Source Plug...

Страница 10: ...ou need to first select the Manual On Off option by placing the Auto Turn On switch on the rear panel to its middle Man Manual position Connecting an Active Audio Source for Automatic On Off If you wa...

Страница 11: ...utomatically turn on and off the A 21 with an external DC voltage choose the DC Triggering option by moving the Auto Turn On switch on the rear panel to its lower 12V position What You ll Need A cable...

Страница 12: ...matically there is 12 Vdc present at its own DC Trigger Out jack so it can trigger additional amplifiers or other components on and off What You ll Need A cable with a 2 5 mm sub mini plug on each end...

Страница 13: ...oblem Please contact Parasound s Technical Service Department Left and Right Channel Status Indicators These are two small round indicators in the center of the recess in the front panel The indicator...

Страница 14: ...oltage for your unit is marked on its carton Changing the A 21 s operating voltage involves rewiring internal connections for both its main power transformer and standby power transformer plus changin...

Страница 15: ...able 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 of water or glass...

Страница 16: ...Mono Bridge switch is in the Mono bridged position Damaged speaker Move to the correct position for the jack in use Balanced Unbalanced Input switch is in the incorrect position Not enough ventilation...

Страница 17: ...cept any of the following Units with collect shipping charges Units without a valid RA number Units without a suitable shipping carton Units for which we see or hear evidence of improper packing For a...

Страница 18: ...ive signals For example when a 1 Volt signal arrives at a balanced input stage the differential input sees a positive 1 Volt minus a negative 1 Volt or 2 Volts total External hum and noise that someho...

Страница 19: ...This separates the A 21 s signal input ground from its chassis ground to isolate unwanted voltage in the ground shield of the unbalanced RCA input cable Be sure your system installation is finished b...

Страница 20: ...o drive the MOSFET drivers in the following stage Circuit designed by John Curl Parasound design consultant John Curl has been a legend among audiophiles and electronic engineers for decades He pionee...

Страница 21: ...these fuses halt operation to minimize damage to additional parts The Driver Stage The driver stage provides critical amplification for which we employ a complementary matched pair of MOSFETs selected...

Страница 22: ...ced 66 k Input Sensitivity for 28 28 V Output into 8 Unbalanced 1 V Balanced 1 V per leg Features and specifications subject to change without notice Loop Output Level Same as input level S N Ratio 11...

Страница 23: ...Parasound Products Inc 950 Battery Street San Francisco CA 94111 415 397 7100 Fax 415 397 0144 www parasound com...

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