Krell Industries KRC-HR Quick start guide

Leader in Audio Engineering
KRC-HR
PREAMPLIFIER
OWNER’S REFERENCE

TABLE OF CONTENTS
2
3
4
5
6
7
8
9
10
11
12
14
15
INTRODUCTION
UNPACKING
THEATER-THROUGHPUT SETUP
BASIC INSTALLATION
INPUT/OUTPUT CONNECTIONS
REAR PANEL DESCRIPTION
BASIC PREAMPLIFIER OPERATION
FRONT PANEL DESCRIPTION
REMOTE CONTROL
PROTECTION CIRCUITRY INDICATORS
QUESTIONS AND ANSWERS
SPECIFICATIONS
WARRANTYAND SERVICE

INTRODUCTION
Thank you for your purchase of the KRELL KRC-HR remote control
preamplifier. The KRC-HRcombines refinements of the original KRCwith a
radical approach to volume control circuitry. The HRdesignation signifies
HIGHESTRESOLUTIONdue to the substantial improvement in sonic quality
provided by our most sophisticated electronic volume control. The unit also has
a Theater-Throughput, which allows easy installation of the unit within a home
theater system. Please see page 4 for details on setting the KRC-HRfor the
Theater Throughput function prior to installation.
To obtain the best performance from your KRC-HR,careful attention should be
paid to its placement, installation and operation. A thorough understanding of
these details will help insure satisfactory operation and a long life for the
KRC-HRand related system components.
This Owner’s Reference is divided into several sections, each designed to
perform a different function. As you read through the Owner’s Reference you
will become better acquainted with the features and functions that make the
KRC-HRa superb value. A Question and Answer section is included where
answers to common questions are provided. If you have any questions or
suggestions, please do not hesitate to contact your authorized dealer or the
KRELLstaff for assistance.
In the unlikely event that your KRC-HRrequires service, you will be pleased to
know that it is backed by a comprehensive Customer Satisfaction policy and
one of the most advanced service facilities in the industry. For detailed
information on the terms and conditions of service, please consult your
warranty registration card, or contact your authorized KRELLDealer or
Distributor.
2

UNPACKING
i. Open the box and remove the top layer of foam.
2. Remove the KRC-HRand the foam tray surrounding it. The following items
will nowbe visible:
1 KRC-HR power supply
1 KRC-HRremote control
1 8 ft. DCpower cable
1 T- 10 torx (for remote)
1 T-15 torx
1 AC power cord
If any of these items are not included, please contact your authorized dealer
immediately for assistance.
3. Removefrom the plastic bags, the preamplifier, power supply, remote control
and power supply cable connectors.
NOTE:Save all packing materials. If you must ship your KRC-HRin the future,
repack the unit with the power supply and remote control in its original packing
to prevent damagein transit.
CAUTION: Do not connect the power cord from the power supply into the AC
mains before completing the "Installation" section.

THEATER-THROUGHPUT SETUP
NOTE: If the KRC-HRmust be handled after the top cover has been removed,
the unit must be held only on the sides of the chassis. Never move the KRC-HR
while the top cover is off by holding the front panel.
Whenreinstalling the top cover, insert the four screws into the chassis sides
first and lightly tighten them. Install the screws in the top surface and tighten
them lightly. Then tighten all screws firmly, starting with the side screws and
finishing with the top screws.
SETTING THE $4 INPUT FOR THROUGHPUTFUNCTIONS
This procedure should be done with the unit OFF.
a. Remove the KRC-HR top cover screws with the T-15 Torx wrench
supplied.
b. Locate the switch towards the front of the board that is labeled S4/Proc.
Set the dip switch to the proc (processor) position.
NOTE: The default position of this switch sets the $4 input for standard
operation. In this position, $4 is identical to the S1, $2 and $3 inputs.
c. Place the top cover back on the KRC-HRand insert the cover screws.
©
© ~ Proc.
¯ ¯
¯ ¯
¯¯
¯ ¯
¯ ¯
¯ ¯
¯ ¯
¯ ¯
¯ ¯
¯ ¯
4

BASIC INSTALLATION
1. Place the unit on a firm level surface free from excessive dirt or moisture.
The KRC-HRis not particularly hum sensitive, allowing other components to
be placed on or around it. If the optional phono card is installed in the
KRC-HR, some components such as Digital to Analog converters, power
supplies or components with motors can induce hum into the phono stage.
2. Place the power supply in a location away from hum sensitive components
such as turntables or phonostages. Connect the male end of the DC power
cable into the computer-type connector on the back of the supply. DONOT
PLUG THE POWERSUPPLY INTO THE AC OUTLET AT THIS TIME.
3. Connect the female end of the DC power cable to the computer-type
connector on the back of the KRC-HR.
CAUTION: ALWAYS CONNECT THE DC CABLE TO THE BACK OF THE
KRC-HR AND TO THE POWER SUPPLY BEFORE YOU PLUG THE POWER
SUPPLY INTO THE WALL OUTLET. FAILURE TO FOLLOW THE
CONNECTION SEQUENCE WILL CAUSE DAMAGE TO THE KRC-HR.
4. Plug the ACcord into the receptacle on the back of the power supply. Plug
the remaining end into the wall ACreceptacle.
NOTE: While the KRC-HR has superb regulation and does not require a
dedicated AC circuit, we strongly advise against any connections through
extension cords or multiple AC adaptors. High quality 15 amp line
conditioners or grounded ACstrips are acceptable.
5. When the KRC-HRpower supply is plugged into the wall AC outlet the
preamplifier will go through its power-up sequence:
a. The volume control will automatically rotate to the Off position, fully
counterclockwise.
b. The Select section LEDson the KRC-HRwill remain unlit until an input or
function is selected.
c. The Protection relays will open once the monitoring circuits have
determined there are no input or output disturbances. See the PROTECTION
CIRCUITRYsection of this manual for more information.
6. The power-up sequence lasts about 15 seconds. Once completed, the
KRC-HRcan be operated from the front panel or the remote control.
5

INPUT AND OUTPUT CONNECTIONS
CAUTIONS:When making connections to this component or any other, make sure
that the power amplifier is OFF. Make sure all cable terminations are of the
highest quality, free from frayed ends, shorts or cold solder joints.
1. Connect the left and right inputs of your source equipment to the inputs on
the KRC-HR. The KRC-HR is equipped with 4 single-ended inputs, 2
balanced capable inputs and 1 single-ended tape input.
2. If the optional phono card is included in your KRC-HR,the turntable’s phono
leads will be connected to the PH input. If the phono card is not in the
KRC-HR,the PH input remains a standard line-level input.
3. If the Theater-Throughput option is to be used, connect the Main L/R
outputs of the A/V surround processor to the $4 input.
When $4 is selected, the KRC-HRwill act as a unity gain throughput, (no
change in level), for this input. All control of level will now be
performed by the A/V surround processor.
4. Connect the main output of the KRC-HRto the input of your power amplifier.
The KRC-HRhas both balanced outputs via XLR connectors and single-
ended outputs via RCAconnectors.
The pin assignment for the XLRinputs and outputs are:
Pin 1 Shield (ground)
Pin 2 Non-inverting (hot)
Pin 3 Inverting
The RCAcenter conductor for each channel is wired in parallel with pin 2. Only
one of the preamp outputs should be connected to an individual amplifier. They
can be used simultaneously to drive amplifiers in two different systems.
When connecting inputs or outputs to the KRC-HR, remember that the
balanced connections will have 6dB more gain than the single-ended
connections. Whenlevel matching is critical in your installation, keep this
specification in mind.
6

REAR PANEL DESCRIPTION
INPUTS
Four single-ended inputs via standard RCAconnectors
PH(Line level input if phono board is not installed)
S-2
S-3
S-4
Two balanced inputs via standard XLRconnectors
B-1
B-2
Tape input via standard RCAconnectors
MAIN OUTPUTS
Single ended RCAoutput connectors
Balanced XLRoutput connectors
Balanced XLRoutput pin configuration:
Pin 1 Shield (ground)
Pin 2 Non-inverting (hot)
Pin 3 Inverting
TAPE OUTPUT
Record output via RCAconnectors
7

BASIC PREAMPLIFIER OPERATION
The KRC-HRhas the flexibility of a remote controlled device but does not
require special attention in order to perform simple functions. The KRC-HRwill
function much like. other KRELLpreamplifiers. The unit can be operated from
the front panel controls or via the remote control. All functions available on the
front panel can also be accomplished from the KRC-HRremote control. This
provides the ability to sit in your favorite listening position while controlling all
system start-up preamplifier functions.
1. Press the Mute button on the KRC-HR.
2. Turn the volume control fully counterclockwise to the OFFposition.
3. Turn the power amplifier ON.
4. Choose a listening source and select that input by pushing the
corresponding input button on the KRC-HR.
5. Start play of the source.
6. Turn the volume control clockwise until you reach a comfortable listening
level.
7. When changing sources, return to the Mute position and/or lower the
volume. This insures that the next source you play will not be potentially
damaging to your system with a high output level.
THEATER THROUGHPUT
The $4 input of the KRC-HRcan be set to operate as a unity gain stage. This
removes the KRC-HRvolume control from the signal path. Volume control is
then transferred from the KRC-HRto an A/V surround processor connected to
the $4 input. This feature greatly simplifies the installation of a surround-
sound processor into a high performance audio/video surround system.
If the Theater-Throughput option is activated, select S-4 when your home
theater/surround system will be used. In this mode, all control of volume is
performed by the A/V surround processor connected to that input. Specifically,
Level, Balance and Gain are disabled on the KRC-HRfor the S-4 input only
when the Theater-Throughput is engaged. Mute and Tape (monitor input) will
function normally.
8

FRONT PANEL DESCRIPTION
INPUT SELECTION
PH
S-2
S-3
S-4
B-1
B-2
Selects phono input (line level input when phono board
not installed)
Selects S-2 input
Selects S-3 input
Selects S-4 input
Selects B- 1 input
Selects B-2 input
FUNCTIONS
TAPE
PHASE
GAIN
MUTE
L BALANCE
R BALANCE
VOLUME
Selects tape input and allows monitoring of tape return
Inverts absolute polarity of the main output 180 degrees
LEDilluminates when polarity is reversed
Low6dB, High 12dB. LEDilluminates in High position
No signal output when LEDis on
Left channel attenuation in 1 dB increments and OFF
Right channel attenuation in 1 dB increments and OFF
Stepmotor driven optical encoder
9