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.
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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

REMOTE CONTROL
1. Whena function button on the remote control is pressed and held, the blue
pilot LED will flash on the KRC-HR. When the button is released, the
flashing stops. This indicates that the KRC-HRhas received a command.
2. The functions of the remote control are identical to the front panel functions.
BATTERY INSTALLATION
Batteries should be replaced when the KRC-HRfunctions from the remote
control become intermittent.
1. Remove the four hex head screws from the back of the control, with the T- 10
torx supplied.
2. Remove the back plate to expose the battery storage compartment.
3. Replace batteries (Refer to the polarity (+-) markings while inserting
batteries for proper installation).
4. Replace the back plate and insert the four hex head screws.
10

PROTECTION CIRCUITRY
The KRC-HRis the first high-end preamplifier to have protection circuitry at
the input and output. The indicators on the KRC-HR, which are described
below, will give you a general location of a problem in your audio system.
1. Whenthe KRC-HR’s monitoring circuitry recognizes excessive DC levels at
one of the inputs, the output disconnects from the front-end circuits and the
LEDcorresponding to that input will flash repeatedly until the problem is
removed. If you try to select that input, the preamplifier will not respond to
the command.
To check the input, remove the cables corresponding to the flashing input
and inspect them with an ohm meter. The flashing LED should become
steady within 5 seconds of removing the suspect input. If the cabling
appears to be sound, try another source component into the suspect input.
If the KRC-HRLED continues to flash, unplug the unit and contact your
dealer or KRELL. If the problem ceases, have the component originally
connected to that input checked out at your dealer or at the factory.
2. If the KRC-HR’smonitoring circuitry recognizes a short at the output, the
output disconnects from the front end circuitry, the DC voltage to the
preamplifier’s circuits disconnects and the blue power LEDflashes. Remove
and check all the cabling and components connected to the KRC-HR.Unplug
the KRC-HRfrom the ACwall socket. Wait for one minute and plug the unit
back into the ACwall socket. The flashing blue power LEDshould now stop
flashing and the unit should follow the standard turn on sequence. If the
unit does not perform in this manner, contact your dealer or KRELL.
11

QUESTIONS AND ANSWERS
Q. When I turn up the volume on the KRC-HR,a loud hum is present from the
loudspeakers. What could this be?
Ao Humcan be caused by several different disturbances. Check to make sure
that all of the cables, (in and out of the KRC-HR)are sound and making
proper contact. Make sure that there are no power supplies or hum
inducing components on top of or directly below the KRC-HR.
You could also be experiencing a ground loop in the system. Put a 3-prong
to 2-prong ACadaptor, (cheater plug), on the KRC-HRpower cord. The hum
should go away. You may also need to float ground on other system
components, if the hum remains. Please contact your dealer or the product
manufacturer before a non-KRELL component’s ground is lifted. Remember
to always keep at least one component grounded. If these suggestions do
not lead to a solution, please consult your dealer or KRELL.
Q. Can the KRC-HRbe used to control more than one system?
A. Yes, the KRC-HRhas both single-ended and balanced outputs that can be
used simultaneously to control two different systems, but both systems will
play from the same input, at identical volume settings.
Q. When I select the B-1 input on the KRC-HR,one channel seems to have less
gain than the other. Is something wrong with the preamp?
A. Probably not. The balanced input or output internal cable terminals could
be attached incorrectly. Locate the channel that appears to have less gain.
Switch the cable connected to that channel’s input to the other channel and
vice versa, to determine whether a cable is defective. If there is no difference
in level, do the same thing at the output of the KRC-HR.If the problem is
not the cable, check to make sure that the input and output connections
are connected at the correct locations on the preamp. There should be no
LEDs illuminated in the Balance control section of the front panel
(indicating a level imbalance).
12

Q. Why do I have to turn up the volume so high to get music at a normal
listening level?
Ao If your system does not seem to have enough gain, you are probably not
using the balanced input and output capabilities of the KRC-HR. Each
balanced termination has 6dB more gain than a single-ended termination.
More important, however, is that the balanced lines provide superior sonic
quality. If you must use single-ended terminations, use the High gain
setting, which has 6dB more gain than the Lowposition.
Q. The pilot LED in the KRC-HRand its power supply are not illuminated.
What should I do?
Check the fuse in the back of the power supply. If there is a break in the
wire inside the fuse, replace it. If there is no break in the fuse, call your
dealer or KRELL. If, when you replace the fuse, the unit powers up and
shuts off shortly thereafter, call the factory.
Q. When I push the function buttons on the KRC-HR remote control, the
preamp does not respond. What should I do?
A. Check the batteries and change them, if necessary.
Q. The selected input button on the KRC-HRis blinking on and off. I cannot
stop the blinking, nor can I play music, what is wrong?
A0 That selected input has developed a problem, causing the KRC-HR to
disable that input. After correcting the problem, the unit will return to
normal. Refer to the section on Protection Circuitry (Page 1 1), for a more
detailed explanation.
13

SPECIFICATIONS
GAIN:
6dB or 12dB
SIGNAL TO NOISE:
96dB unweighted
THD:
1KHz less than .01%
20KHz less than .01%
INPUT IMPEDANCE:
47,000 Ohms (47K Ohm)
OUTPUT IMPEDANCE:
5 Ohms
OUTPUT VOLTAGE:
14 volts R.M.S.
DIMENSIONS:
Unit:
19.0" Wide
14.5" Deep
2.75" High, with feet
Power Supply:
1 1" Wide
9" Deep
2.5" High
All operational features, functions, and specifications and policies are subject to change
without notification.
14

WARRANTY AND SERVICE
THERE ARE NO USER-SERVICEABLE PARTS INSIDE ANY KRELL PRODUCT.
The KRELLKRC-HRhas a limited and transferable warranty of five years for
parts and labor. The warranty period begins on the date of retail purchase, as
noted on the retail sales slip provided by an authorized KRELLDealer or
Distributor, or on the warranty registration card sent to KRELL.In the event
adequate proof of purchase date is unavailable, the warranty period will begin
on the date the unit was originally shipped from the factory. The original ship
date can be determined by KRELLfrom the serial number.
The warranty for KRELLproducts is valid only in the country to which they
were originally shipped, through the authorized KRELLDistributor for that
country, and at the factory. There may be restrictions on, or changes to
KRELL’s warranty because of regulations within a specific country. Please
check with your Distributor for a complete understanding of the warranty in
your country.
Freight to the factory is your responsibility. Return freight within the United
States is included in the warranty. If you have purchased your KRELLproduct
outside the United States and wish to have it serviced at the factory, all freight
and associated charges to the factory are your responsibility. Krell will pay
return freight to the US-based freight forwarder of your choice. Freight and
other charges to ship the unit from the freight forwarder to you are also your
responsibility.
The operating voltage of this unit is determined by the factory and can only be
changed by an authorized KRELLDistributor or at the factory. The voltage for
the KRC-HR in the USA can not be changed for six months following the
original purchase date. Any unauthorized voltage conversion, disassembly,
component replacement, perforation of chassis, updates, or modifications
performed to the unit will void the warranty.
15

WARRANTY AND SERVICE
KRELLis not responsible for any damage to units incurred in transit. If any
shipping damages are incurred during transit of your units to the factory, you
must initiate filing of the insurance claim. Likewise, KRELLwill file claims for
shipping damages incurred during transit of your units from the factory to you.
The use of any packing material other than original is not recommended.
KRELLmay, at its discretion, pack a unit in new material for the return
shipment. Krell will bill you for such if the unit was shipped in non-standard
packing or if the original packing is so damaged as to be unuseful. Should you
need to purchase additional packaging please contact your authorized KRELL
Dealer, Distributor or KRELLfor assistance.
IMPORTANT:If you think there are problems with your unit, please contact your
Dealer, Distributor, or the factory immediately. Do not return any unit to KRELL
for repair without first calling to discuss the problem and obtaining a Return
Authorization number
All operational features, functions, and specifications and policies are subject
to change without notification.
16

KRELL
45 Connair Road ¯ Orange, CT 06477-3650 USA
203-799-9954 ¯ Fax: [phone]
©1997by Krell®Industries, Inc. All rights reserved.
P/N 1960602000023