Parasound HCA-1206 User manual

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HCA-1206 High Current Multi Amplifier
O W N E R ' S M A N U A L
Congratulations on your purchase of this precision audio component and thank you for your selection of
Parasound. Your HCA-1206 was designed by renowned circuit designer John Curl to meet or surpass
the stringent standards required by Lucasfilm for use in THX Home Cinema systems. Each part within
your HCA-1206 has been painstakingly selected for optimum sound quality on even the most
challenging music and film soundtracks. Please take a few moments to read these instructions so you
may fully understand the capabilities of your new Parasound power amplifier.
Unpacking Your HCA-1206
The HCA-1206 is packed in two strong cardboard cartons. To unpack the amplifier, open both cartons
and carefully remove the HCA-1206 from its inner carton. You may use its rear handles to facilitate
removal from the carton. Take care not to cut or scratch yourself on the exposed extruded metal
heatsinks on either side of the unit. Save your cartons and the packing inserts for safe transport in case
you move or if the unit ever requires shipping for repair. Due to the massive weight of the HCA-1206,
the inner white printed carton is not strong enough for safe shipping by itself. You absolutely must
place it into the additional outer over-carton before shipment.
The audiophile grade AC cord is packed separately in the carton. This is the only cord we recommend
for use with your HCA-1206. Please do not lose it. Before you proceed, find the serial number which is
located on the rear panel of your unit and record it here for future reference or in case of casualty loss or
theft: _____________
Overload
Overload
CH1
CH 1 CH2
CH 2 CH3
CH 3 CH4
CH 4 CH5
CH 5 CH5
CH 5
Power Power
Operation
Operation
Standby
Stand by
HCA-1206 High Current Multi Amplifier
LUCASFILMLUCASFILM
LUCASFILM
¤
®
LUCASFILM

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Placement of Your HCA-1206
Place your HCA-1206 away from heat sources such as hot air ducts or radiators. Make sure that your
cabinet or shelf can support its enormous weight. Always place your unit horizontally. Do not place your
unit directly on a carpet whose pile could interfere with air flow into its bottom vent openings or heat
sinks. If you place your HCA-1206 on the floor near your speakers, elevate it above the pile of the
carpet. If you stack your components, it is better to place your HCA-1206 alongside other components.
Rack Mounting Your HCA-1206
Your HCA-1206 can be mounted into a standard EIA 3 unit 19" rack. Make sure you select heavy duty
mounting bolts and nuts and use washers under the heads of the bolts to avoid scratching your amplifier’s
anodized front panel. Do not attempt to hold your unit in place yourself while you attach the bolts and
nuts. Have a strong helper support the unit as it is being attached to the rack. The heat generated by the
HCA-1206 may require a fan to assist air flow and if you have another component mounted directly
above it in the rack.
Ventilation Requirements for Your HCA-1206
Your Parasound power amplifier is designed to operate with high idling, or bias, current to reduce higher-
order harmonic distortion. This bias optimization is characteristic of all Parasound power amplifiers and
is perfectly normal, but it results in noticeably warm operation even when no signal is present. While
many other amplifiers manufacturers have chosen to bias their amplifiers at a lower level to run cooler,
we bias our amplifiers so the output transistors are allowed to operate in a much more linear region.
Although the amplifier may run a little warmer than other amplifiers, we feel the resulting sonic
improvements are significant and justified.
However, to insure safe and reliable operation, it is very important that the amplifier has plenty of
ventilation to prevent overheating and automatic shut down from the thermal protection circuitry.
Please observe the following guidelines when installing your Parasound power amplifier:
1. If you are not using a fan, allow at least six inches on each side and above the amplifier, and
do not close off the front with a door or panel.
2. If you are enclosing the amplifier in an equipment cabinet, use a fan and draw in cool air or
exhaust warm air. In either case, two vent holes are required: one for intake and one for exhaust.
3. Do not place the amplifier on carpeting which will obstruct the air flow from the bottom of the
amplifier.
4. If you plan on stacking amplifiers, you must use a fan.
Minimum Impedance Precautions
You may connect loudspeakers with a 4 Ω or 8 Ω nominal impedance for unbridged operation. Your
HCA-1206 is capable of driving speakers with occasional impedance dips well below 2 Ω. However,
Lower nominal impedance loads are not recommended and may cause overheating.
The HCA-1206 is designed for a minimum 8 Ωnominal impedance for each speaker connected to
bridged channels 3+4 or 5+6. Use of lower impedance at high listening levels may cause overheating or
trigger one of the amplifier's protection circuits.
These restrictions result from the mathematics of the bridging circuitry. In the bridge mode each channel
of the amplifier functions for only the + or — half of the musical waveform. Thus, each channel "sees"
only half of the speaker’s impedance. Use of an 8 Ωspeaker means that the load for each channel is
4 Ω. And for a 4 Ωspeaker, it would result in only 2 Ω.

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HCA-1206 Front and Rear Panel Controls
Figure #2 HCA-1206 Front Panel Controls
Figure #1 HCA-1206 Front Panel Controls
Overload
CH 1 CH 2 CH 3 CH 4 CH 5 CH 5
Power
Operation
Stand by
Power Switch
Standby/Operation
LEDs
Current Overload LEDs
EIA Rack
Mount Holes
HCA-1206 HighCurrent Multi Amplifier
LUCASFILM
LUCASFILM
HCA - 1206
High Current Multi-Amplifier
Parasound Products, Inc
San Francisco, CA U.S.A.
CAUTION:
TO PREVENT ELECTRIC SHOCK,
DO NOTREMOVE COVER. NO USER
SERVICEABLEPARTS INSIDE. REFER
SERVICING TOQUALIFIED SERVICE
PERSONNEL.
Power Consumption: 600 W
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
Inputs Fuse 15A
+
Power
AC 120V 60Hz
WARNING:
TO PREVENT FIRE OR SHOCK
HAZARD.DO NOT EXPOSE THIS
UNIT TO RAINOR MOISTURE.
Mono
Bridging
Separate CH 3, CH 4
Loop 1/2-3/4
On
Off
Loop 1/2-3/4
On
Off Mono
Bridging
Separate CH 5, CH 6
Non-
Bridgeable Mono
Bridging
8 ΩMin
Mono
Bridging
8 ΩMin
+
Levels
CH 6CH 5CH 4CH 3CH 2CH 1
Main Fuse
AC Cord Connector
Carry Handle
Bridge Switches
Input Looping
Switches
Level Controls
Input Connectors

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Input Connections and Switch Settings for the HCA-1206
Refer to Figure #2
Six Channel Operation
The six channel mode of your HCA-1206 can power the six speakers required for a complete home
theater: Front left and right, surround left and right, center channel, and subwoofer. Connect each output
from your surround processor to the corresponding input connector of your HCA-1206.
If you are using your HCA-1206 in the six channel mode, we suggest the following progression of
channel priorities. This is an easy way to remember what you connected to each channel for setting
levels or troubleshooting:
Recommended Input Connections for Six Channel Operation
Use INPUTS 1 and 2 for your front left and right channels
Use INPUTS 3 and 4 for your left and surround right channels
Use INPUTS 5 for your center channel
Use INPUTS 6 for your passive subwoofer
Switch Settings for Six Channel Operation:
Leave LOOP 1/2 > 3/4 and LOOP 1/2 > 5/6 switches in their OFF positions and both MONO BRIDGE
switches in their SEPARATE positions.
Four and Five Channel Operation
In addition to six channel operation, you can use your HCA-1206 in a variety of other configurations
depending upon your needs. Below are examples of four and five channel operation.
Input Connections for Four Channel Operation
Use INPUTS 1 and 2 for your front left and right channels
Use INPUTS 3 and 4 bridged mono for your center channel
(Connect the center output of your processor to INPUT 4 only)
Use INPUTS 5 and 6 bridged mono for your subwoofer
(Connect the subwoofer output of your processor to INPUT 6 only.)
Use an additional amplifier for your surround channels
Switch Settings for Four Channel Operation:
Leave LOOP 1/2 > 3/4 and LOOP 1/2 > 5/6 switches in their OFF positions
Set the MONO BRIDGE switch for channel 3/4 in the MONO BRIDGING position
Set the MONO BRIDGE switch for channel 5/6 in the MONO BRIDGING position
Input Connections for Five Channel Operation
Use INPUTS 1 and 2 for your Front left and right channels
Use INPUTS 3 and 4 for your left and right surround channels
Use INPUTS 5 and 6 bridged mono for your center channel
(Connect the center output of your processor to INPUT 6 only)
Settings for Five Channel Operation:
Leave LOOP 1/2 > 3/4 and LOOP 1/2 > 5/6 switches in their OFF positions
Select the MONO BRIDGE switch for channel 3/4 in the SEPARATE position
Select the MONO BRIDGE switch for channel 5/6 in the MONO BRIDGING position
Use a powered subwoofer or an additional amplifier for a passive subwoofer

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Multi-Zone Stereo Operation
You can switch your HCA-1206 to reproduce a single stereo source through up to three pairs of stereo
channels via input cables connected to channels 1 and 2 input jacks only. This permits a neater and less
confusing hookup. It eliminates the requirement for two or four “Y” adapters in order to split your
preamplifier’s single pair of stereo outputs to feed the 3 pairs of HCA-1206 power amplifier input jacks.
When you switch the LOOP 1/2 > 3/4 Switch for channels 3 and 4 to its ON position, these channels
receive the internally paralleled looped input signals from the same cables connected to the inputs of
channels 1 and 2. Input 1 loops over to channel 3. Input 2 loops over to channel 4.
The Loop 1/2 > 5/6 Switch for Channels 5 and 6 offers the same internal paralleling convenience. Input
1 loops over to Channel 5. Input 2 loops over to Channel 6.
Speaker Connections to the HCA-1206
Refer to Figure #2
Five-Way Binding Posts
The five-way binding posts on the rear panel of your HCA-1206 will accept banana or dual banana
plugs, most 1/4" spade lugs, or up to AWG 12 bare solid or stranded wire.
Polarity
It is important to observe correct speaker connection polarity to prevent phase cancellation. One side of
the speaker wire will have some sort of mark, either printing, a raised ridge on the insulation or a
different color of conductor. This permits you to know which wire you had connected to the + and
which to the — speaker terminals so you can do exactly the same at the power amplifier terminals.
Polarity is marked separately for both stereo and bridged connections.
Banana Plugs
Banana plugs offer the most convenient connection to the speaker terminals. They also have a large
amount of surface contact into the speaker terminal. For these reasons, we recommend the use of
banana plugs in most applications. However, you may want to use the “gas tight” connection provided
by spade lugs or bare wire.
Spade Lugs
If you prefer to use speaker cable with spade lugs, make sure you do not permit the lug to rotate as the
terminal is tightened. Do not overtighten the speaker terminal onto the spade lug. The limited warranty
does not cover terminals that are sheared off as a result of overtightening.
Bare Wire
If you use bare wire without plugs, make sure you strip off only enough insulation so the bared wire fits
into the hole that runs sideways through the terminal’s metal shaft. Before inserting the wire, twist all its
strands tightly to prevent strays that could cause a short circuit between + and — terminals or adjacent
channel terminals. If you have a soldering iron, it is a good idea to “tin” the bare wire with solder to
keep it from unraveling and prevent oxidation.

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Mono Bridging — Channels 3+4 and 5+6
When you bridge channels 3+4 and/or 5+6, your speakers are connected to the bridged channels
differently. You bridge by using the red + terminals of the adjacent channel pairs only. Note that
bridged connections are made horizontally rather than vertically and the upper red + terminals have
separate markings for bridging. In the bridged mode, channel 4 (and/or 6) output is positive and channel
3 (and/or 5) output is negative.
Unbridged speaker connections can be made with standard 3/4" (19 mm) dual banana plugs. However
internal space required by the high current protection relays prevent the bridged terminal pair spacing to
be close enough to accept 3/4" (19 mm) dual banana plugs. Single banana plugs, spade lugs, or bare
wire termination are required.
Select MONO BRIDGING (up) or SEPARATE (down) as marked on the rear panel. Switch the power
off before moving either of these switches. If you accidentally leave either switch in the mono bridge
position, the stereo output will be very weak and distorted.
For bridged operation of channels 3+4, use only the input jack and level control for channel 4.
For bridged operation of channels 5+6, use only the input jack and level control for channel 6.
Use Good Speaker Wire
For best results, you should never use speaker wire thinner than 16 AWG and keep the length of speaker
wire as short as possible to maintain a high damping factor and avoid deteriorating bass response. You
may also wish to experiment with audiophile-grade speaker wire and interconnects.
The benefits of these are debated among audio hobbyists, and we cannot guarantee you will always
hear an audible improvement.
AC Power Connections and Audiophile-Grade AC Cord
Before you attach the AC cord, make sure the HCA-1206 power switch is in its off position. Your
HCA-1206 includes a detachable audiophile-grade AC cord. We recommend that you use only this cord
and make a direct connection to the AC wall outlet.
Do not connect the amplifier to the accessory AC outlet on your preamplifier. The current draw exceeds
the ratings of most preamplifier’s power switches and power cords and could cause premature failure of
the switch.
If you use an external AC line conditioner/surge suppressor, make sure it can handle the full power
required by the amplifier. If you want the very best sound possible, you might consider having a
licensed electrician run a dedicated AC power line for your HCA-1206. This will isolate it from most of
the power line interference caused by older wiring and household appliances.
While 3 pin grounded AC cords are standard on most high end components, sometimes it becomes
necessary to "lift" the ground or reverse the polarity of the AC plug to reduce hum. In this case, you
may use a 3 pin -to- 2 pin AC plug adaptor, or “cheater” plug, which is readily available at a low cost
from any hardware store. This will not compromise the sound quality of your system.

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Operating Your HCA-1206
Refer to Figure #2
Power Switch
Press the upper side to turn the unit on; press the lower side to turn the unit off.
Standby/Operation LEDs
The red Standby LED will come on red whenever you first turn the unit on. It will light for about four to
five seconds while the amplifier circuits are stabilizing before the six protection relays start to energize.
At this time the red LED will turn off and the green Operate LED will come on to signal normal
operation. It will also light up red whenever there is a short circuit or fault which triggers the protection
circuits. Whenever the red LED illuminates, no sound can be heard. If the red Standby LED lights up
during operation it could indicate that more DC is present than its servos can handle, a short circuited
speaker line, or possible internal fault. Once the problem has been corrected, the protection circuits will
automatically reset. Turn the unit off for at least 10 minutes while you check your connections, then try
again. If the red LED continues to glow, contact your Dealer, Installer or Parasound Technical Service
for further advice.
Current Overload LEDs
The current overload LEDs for channels 1 through 6 will only illuminate if the unit is driven
continuously at or past its maximum current capacity. These LEDs will indicate overload of the power
supply just before the onset of audible distortion. In virtually all imaginable listening situations, these
LEDs will rarely illuminate.
Level Controls
Each channel has a separate input level control. The HCA-1206 will sound best with its level controls
set to maximum, where they are effectively out of the audio signal path. However, if your preamplifier
has very high gain, and its volume control cannot track properly for left-right channel balance near its
minimum position, it may be necessary to reduce the input level control settings on the HCA-1206. We
deliberately have located the controls on the rear panel, so they can be set once and forgotten.
Burning-in your HCA-1206
Like other great power amplifiers, the HCA-1206 requires at least 72 hours of continuous operation after
it is first turned on to sound its best. This gives the materials in various parts a chance to form so audio
signals achieve greater definition, smoothness and transparency.
Although the unit will sound spectacular when you first operate it, you will find it worthwhile to listen
again after a few days and you’ll discover details in your music and videos you may not have guessed
were there.
Maintaining your HCA-1206
Your HCA-1206 requires no periodic maintenance and has no user serviceable parts inside. Do not
remove the top cover to avoid risk of electric shock. To keep it clean use only a soft cloth and never use
any solvents or abrasives. Fingerprints may be removed with a soft cloth moistened only with a few
drops of water.
The amplifier has corrosion-free gold input jacks, but each year it is a good idea to twist the input plugs
to preserve perfect signal transfer by removing corrosion which might have accumulated on the
connecting plugs themselves. Make sure the unit is turned off while you do this.

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Fuse
The HCA-1206 has one external 15 ampere fuse which may blow as a result of an internal fault
condition. This protects the unit from possible damage to internal parts. Never replace this fuse with a
larger value. Substitution of a larger fuse may create serious stress or damage to internal parts and will
void your warranty.
In Case of Trouble
If you suspect a problem with this unit, first recheck all your connections. If only one channel is
inoperative, the trouble may be caused by another component or even a defective hookup cable.
However, if the same channel is at fault when you reverse the Left and Right channel pair cables to your
HCA-1206 (turn it off before moving wires), it may indicate trouble within the power amplifier itself.
We suggest you contact your authorized Parasound Dealer or Installer, or call Parasound Technical
Service if you suspect a problem. We may be able to suggest other diagnostic tests you can easily
perform yourself and which will save you a lot of trouble.
If it is determined that the HCA-1206 should be returned to Parasound for inspection and possible
servicing, you must first call or write to obtain a Return Authorization number. You will also be asked
to repack the unit in its original packing and both of its cardboard cartons for proper protection in transit.
Units that arrive without the correct Return Authorization number, without a suitable shipping carton or
evidence of improper internal packing will be refused. We cannot accept collect shipments. After
repair under warranty, the unit will be returned to you prepaid. If we found no problem with the unit, we
will return the unit with collect charges for return shipping charges.
Parasound HCA-1206 Specifications

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Continuous Power Output
> 135 watts RMS x 6, 20 Hz - 20 kHz, 8 Ω , all channels driven
> 200 watts RMS x 6, 20 Hz - 20 kHz, 4 Ω , all channels driven
Continuous Power Output - Bridged
> 350 watts RMS, 20 Hz - 20 kHz, 8 , each bridged channel, 3+4, 5+6
Current Capacity
30 amperes peak, per channel
Slew Rate
> 130 V/µsecond
Frequency Response
12 Hz - 120 kHz, +0/-3 dB
Total Harmonic Distortion
< 0.07% at full power
< 0.03% typical levels
IM Distortion
< 0.04%
TIM
Unmeasureable
Dynamic Headroom
> 2 dB
Interchannel Crosstalk
> 75 dB at 1 kHz
> 56 dB at 20 kHz
Input Impedances
50 kΩ per channel, without looping inputs 1/2 to Ch. 3/4 or Ch. 5/6
25 kΩ per channel, if looping inputs 1/2 to either Ch. 3/4 or Ch. 5/6
17 kΩ per channel, if looping inputs 1/2 to both Ch. 3/4 and Ch. 5/6
Input Sensitivity
1.0 V THX Reference Level
S/N Ratio
> 118 dB, input shorted, IHF A-weighted
Damping Factor
> 800 at 20 Hz
Dimensions
19" wide x 7" high x 18.5" deep (7 5/8" high with feet)
Weight
71 lbs. net Special Features

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• Designed by John Curl
• THX certified by Lucasfilm Ltd.
• Massive Encapsulated 1.7 kVA Power Transformer with Separate Windings for Each Channel
• 120,000 uF Computer-grade Capacitors in the Power Supply
• Multiple Polystyrene Film Bypass Capacitors to Smooth the Power Supply
• Independent Power Supplies for Each Channel
• Separate Regulated Power Supplies for Driver Stage
• Cascode Class A Input Stages with Matched Complementary J-FET Pairs
• Hand Picked Complementary MOSFETS in High Voltage Driver Stages
• 12 Complementary Pairs of Beta-Matched 50 MHz, 15 Ampere Output Transistors
• Output Transistors Direct-Coupled to Speakers Without LRC Networks
• Linear Tracking, Instantaneous Acting DC Servos
• High-Bias Class A/AB Operation
• Gold-Plated Metal Structure RCA Input Jacks
• Multiple Temperature Sensors and Silver-Cadmium Relay Protection
• FR-4 Glass Epoxy Circuit Boards, Double-Sided for Precision
• Custom Designed Audiophile-Grade AC Power Cord
• Configurable for Multi-Channel Home Theater, Multi-Zone Stereo, Biamp or Triamp Operation
Rewiring Your HCA-1206 for 220 V - 240 V 50 Hz Operation
The amplifier may be rewired for operation abroad. This involves changing several wires on the power
transformer. Please refer this conversion to a skilled electronics technician to avoid personal injury or
possible harm to the amplifier. There are hazardous high voltages present inside the chassis even after
the power is turned off and the AC cord has been disconnected.
As it is supplied for 110 V-120 V operation, the red and white transformer primary wires are connected
together. The yellow and black primary wires are also connected together. The 120 V AC source is
then connected to the black/yellow and red/white wires.
To convert to 220 V-240 V operation, disconnect the white wire from the red wire and disconnect the
black wire from the yellow wire. Next, connect the yellow and white wires are together. The 220 V AC
source is then connected to the black and red wires.
When you change the voltage from 120 V to 220 V, be sure to change the main fuse from 8 amps to 4
Amps
It is quite normal for the power transformer to run a little hotter during 50 Hz operation. This is well
within its safety limits and is no cause for concern.
White
Yellow
110/120 V Operation
Red
Black
Red
Black
Yellow
White
220/240 V Operation

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© 1995 Parasound Products, Inc.
Parasound Limited Warranty (USA only)
Your Parasound HCA-1206 amplifier is covered by a limited warranty against defects in materials and
workmanship for a period of two years from date of purchase. This warranty is provided by the
Parasound dealer where the unit was purchased. Warranty repair will be performed only when your
purchase receipt is presented to validate your ownership, date of purchase and authorized status of the
selling dealer. Defective parts will be repaired or replaced without charge by your authorized dealer’s
store or the location designated by your dealer that is authorized to service Parasound equipment.
Additional information is available by calling or writing to the Service Manager, Parasound Products,
Inc. at the address below. Charges for unauthorized service and transportation costs are not
reimbursable under this warranty.
This warranty becomes void if the product has been damaged by alteration, misuse, accident or neglect.
Alteration includes any removal, obscuration or defacement of its serial number. This warranty
becomes void if unit has been connected or operated contrary to printed instructions. The warrantor
assumes no liability for property damage or any other incidental or consequential damage whatsoever
which may result from the failure of this product. Any and all warranties of merchantability and fitness
implied by law are limited to the duration of this expressed warranty.
Some states do not allow limitations on how long an implied warranty lasts, so the above limitations
may not apply to you. Some states do not allow the exclusion or limitation of incidental or
consequential damages, so the above limitation or exclusion may not apply to you.
This warranty gives you specific legal rights and you may also have other rights which vary state by
state.
Parasound Products, Inc. 950 Battery Street, San Francisco, CA 94111
415-397-7100 / FAX [phone]
affordable audio for the critical listener