Krell Industries KSP-7B User manual

KSP-7B STEREO PREAMPLIFIER OWNER’S MANUAL

45ConnairRoad
Orange,CT06477-0533,USA
INTRODUCTION & GENERAL INFORMATION
Thank you for purchasing the KRELLKSP-7B Preamplifier. The KSP-7B is
the latest evolution of KRELL’sentry level preamplifier technology. Many
of its design concepts are similar to our more expensive preamplifiers and
are wholly unique to KRELL. Two important design features are dual-
mono operation (all active stages are powered by independent tracking
regulators) and the complete absence of any capacitors in the signal path.
The KSP-7B retains other features for which KRELLpreamplifiers have
become recognized: internally switchable loading for moving coil cartridges
and input capacity rarely found on high-end preamplifiers. All circuitry in
the KSP-7Bis of completely new design -- many aspects of which are derived
from the top-of-the-line KRS-Balanced Reference Preamplifier. The most
significant of these is the fully balanced output stage. Balanced circuitry
has long been standard for professional audio equipment and is rapidly
becoming the standard for high-end audio equipment. The sonic benefits of
balanced operation are clearly audible. A simple listening comparison
between the RCA(single-ended) and the XLR(balanced) outputs will reveal
improvements in all areas of sonic quality. The connection of the KSP-7Bin
single-ended and balanced systems is covered on page five.
Please read this manual thoroughly before using the KSP-7B. Installation
and operation are simple to understand and perform.
The KSP-7Bwill provide many years of trouble-free performance. Please be
sure to return the enclosed warranty registration card.
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ABOUT THE OWNERS~ MANUAL
The KSP-7BOwner’s Manualis divided into various groups of information.
The purpose of he document as a whole is to familiarize you with the unit
and guide you through its set-up, installation and operation in a logical
progression. TheTable of Contents is as follows:
A. Unpacking
B. Phono Section Set-Up
C. Installation: 1. Cautions
2. Unit Location Guidelines and Installation
3. Connection of Inputs and Outputs
4. Turn-on of the Preamplifier
D. Operation
E. Warranty and Service Information
A. UNPACKING
Remove the KSP-7B, power supply and accessories from the shipping
container. Store all packing materials in a cool, dry place for future use.
Inspect the unit for shipping damage; if any damage is evident, contact
your dealer immediately. If the unit is in proper condition, proceed with
installation.
In addition to the preamplifier and power supply, you will find a small "L"
shaped allen driver. This is used to removethe top cover to gain access to
the phono section gain and input impedance loading adjustments.
Set-up of the phono section should be completed before installation of the
preamplifier.
B. PHONOSECTION SET-UP
Important Note: For the initial adjustment of the phono section the KSP-7B
should not be connected to its power supply. For adjustments to the phono
section input impedanceafter the initial set-up, as discussed below, please
note the following: Never adjust an_v of the.. internal switches while the
amplifier the KSP-7Bis driving is turned on.

MovingCoil Cartridges:’ The KSP-7Bis shipped with the phono section gain
set for moving coil cartridges and a load of 800 ohms. The load can be
changed with a set of internal switches. To access these the top cover must
be removedwith the supplied allen driver. At the left-rear of the unit there
is a two-position toggle switch. In the factory-supplied position the switch
lever is towards the rear panel of the unit. If you are using a movingcoil
cartridge do not change the switch position. To adjust the input impedance
load for different moving coils use the table below to find the optimum
setting for your cartridge. Follow your dealer’s or the manufacturer’s
~recommendations first. You can also set the load using your sonic
preferences as a guide. In general, lowering the impedance will make the
high frequencies less prominent and the overall sound warmer. Higher
loads makethe overall sound morevivid and detailed. This is, of course,
highly ~ubjective and very dependent on the cartridge in use.
Thevarious load possibilities are detailed below:
all switches in the open position = 47,000 ohms
all switches open except 8 on = 1,000 ohms
all switches open except 7 on = 800 ohms
all switches open except 6 on = 470 ohms
all switches open except 5 on = 250 ohms
all switches open except 4 on = 100 ohms
all switches open except 3 on = 47 ohms
all switches open except 2 on = 25 ohms
all switches open except I on = 10 ohms
all switches on = 5 ohms
Moving Magnet Cartridges: To set the Phono section for Moving Magnet
operation, with the impedance adjusted to 47,000 ohms, set the phono gain
switch towards the front of the preamplifier. This lowers the gain of the
phono section to compensate for the higher output of moving magnet
cartridges. Set all impedanceswitches for both channels to off.
C. INSTALLATION
1. Cautions!
Note: These are important points of which you always should be aware.
Theyare presented before the actual installation procedures, should you not
read through the manual entirely.
a. Donot connect the power cord into the ACmains before completing
the "Installation" section!
b. The power amplifier(s) should always be turned off while making
connections.
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Co Wheninstalling th’e KSP-7B,always connect the DCcable between the
preamplifier chassis and the power supply before plugging the power
supply into the ACmains.
d. AlwaysdisconnecttheAC fromthemainsbeforedisconnectingthe
DC cablefromthepreamplifier.
e. The KSP-7BSelect switch should be in the Mute position and the
volume control fully counterclockwise while making connections.
Our custom RCAconnectors are made to very exacting standards.
Connectors of lesser quality may damage them or cause poor
connections. Please check with your dealer or the factory if you have
any questions.
2. Unit Location Guidelines and Installation
The KSP-7Bis designed to be set-up with the powersupply installed at some
distance from the preamplifier chassis. This is to eliminate the possibility
of humbeing induced into the phono section. The motors in CDplayers or
tape decks can also induce huminto the phono section and, in most cases,
should be placed at least a foot awayfrom the KSP-7B.
Before proceeding with the final installation, please read and complete the
set-up of the phonosection loading. These operations involve removal of the
top cover and are mucheasier to accomplish before the unit is fully in
place. Instructions and settings are listed in Section B (Pages 2 &3).
a. Power Supply Location Guidelines
The KSP-7Bpower supply measures 7 1/4" wide, 8 1/4" deep and 2 1/2"
high. Six foot ACand DCcables are provided with the supply. Plan the
position of the supply and preamplifier within these lengths. Allow a
small amountof cable to be excess so that neither cable is pulled tight.
Contact the factory if the DCcable is too short. Anyattempt to extend it
jeopardizes the power supply and the preamplifier and will void the
unit’s warranty.
Although well-shielded, the power supply should not be placed close to
hum-sensitive components such as turntables, phono preamplifiers or
tape decks.
Allow ample air space around the supply for heat dissipation. Five
inches on top and two inches on each side is adequate. This supply and
any other should not be placed one on top of the other. They should be
placed side-to-side.
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This supply does not’ require that an ACcircuit be dedicated for its use
only. It should be connectedto a 15 or 20 ampcircuit that is dedicated for
the source components and preamplifier. Donot connect this supply to
the mains with light-gauge (18 or higher) extension cords or multiple
outlet adapters. ACextension cords, outlet strips and goodquality surge
protectors that are rated for 15 ampsand are grounded are acceptable.
b. Preamplifier Location Guidelines
The KSP-7Bchassis measures 18 3/8" wide, 13 1/2" deep and 2" high.
Four inches clearance should be allowed above the top of the KSP-7B.
Only a small amount of clearance is needed on the sides. Four to six
inches clearance should be allowed at the rear of the unit to provide for
cables.
c. PowerSupply &Preamplifier Installation
i. Place the power supply in location.
ii. Place the preamplifier in location.
iii Connect the DCcable from the supply to the preamplifier.
iv. Donot plug the ACconnector into the mains at this time, but make
certain the cable length is adequate.
3. Connection of Inputs and Outputs
All source componentsshould be off at this point.
a. Connection of Inuut Sources
Follow the markings on the rear panel for proper input assignments.
Makethe connections between the source components and preamplifier
inputs at this time.
b. Connection of Record Outuuts
There is one set of Record Outputs which receive the signal from the
input chosen on the Select switch for sending to a tape deck. Makethe
connections between the Record Outputs and tape deck at this time.
c. Connection of Main 0~tputs
There are two sets of Main Outputs: one set single-ended using RCA
connectors; one set balanced using XLRconnectors. They are wired in
parallel and can be connected and operated simultaneously. There is no
degradation to either output if both are connected, whether one or both
are in operation at the same time. You may even choose to drive two
independent systems from your KSP-7B.
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i. For use with an~plifiers with single-ended (unbalanced) inputs:
connect the RCAMain Outputs to the amplifier inputs. This constitutes
the conventional hook-up for a single-ended unbalanced system.
ii. For use with amplifiers with balanced inputs: connect the XLRMain
Outputs to the amplifier inputs. The pin assignments are as follows: 1 =
ground, 2 = non-inverted output, 3 = inverted output.
Makethe connections between the Main Outputs and amplifier(s) and/or
crossovers at this time.
4. Turn-on of the Preamplifier
a. Initial Tam-on
All source components should be off at this point. The Select switch
should be set to the Muteposition and the volumecontrol should be fully
counterclockwise. The amplifier(s) should be off.
Connect the power supply to the ACmains at this point. The LEDson
the power supply and KSP:7Bshould nowbe illuminated.
b. Future Use
The KSP-7Bis designed to be "on" at all times. In other words, it is not
intended to be switched on and off on a routine basis. The only times it is
recommended to turn the unit off is when your system will be left
unattended for a long period of time, such as during a vacation or a
business trip. In these cases all other equipment should be turned off,
and the KSP-7B power supply should be disconnected from the AC
mains. Whenyou return, reconnect the power supply to the ACmains
before turning on other equipment.
This procedure should also be followed if you reorganize your system
and need to change wiring of the supply to the preamplifier.
D. OPERATION
Use the Select switch to choose between the various source (playback)
components for listening. Be sure to lower the volume control when
switching amongcomponents, as large differences in level between sources
can cause damage to other components.
There is a Mute position that should be used when source components are
being turned on and off and at the completion of each listening session.
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Note: Componentsthat are not being listened to should be turned off or
have their volume turned down. For instance, a tuner should be turned off
or have its volumeloweredwhile it is not being listened to.
Use the ~ switch to choose between the output of the ~ switch or the
playblack from a tape deck for monitoring. This can be done when a
recording is being made, such as with a three-head tape deck, or during
playback only.
Usethe Gain toggle switch to adjust the overall gain of the line section to
compensatefor different system efficiencies.
Theamountof gain for the two settings of the Gain switch are as follows:
HI: 12 dB
LOW: 6 dB
Use the Phase toggle switch to reverse the absolute phase of the Main
Outputs. The switch is functional for both the single-ended and balanced
outputs.
Manyrecordings have had their overall phase reversed during the various
processing stages. Whenthe absolute phase and phase relationship
between channels is correct, there are improved transients and dynamic
detail.
5. Balance
Use the Balance control to adjust the level between the two channels if
necessary. The Balance control is really a balance attenuator. Whenthe
control is turned clockwise, the left channel is reduced in level in four
single decibel steps; a fifth position, Off, fully clockwise, turns the left
channel off.
6. Volume CQntrol
Use the Volumecontrol to adjust the listening level. It should always be
fully counterclockwise when the system is not in use or when changing
records or sources.
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The KSP-7Bhas a limited warranty of five years from the date of purchase.
Please return the completed warranty card immediately after successful
installation and operation are completed.
The warranty for KRELLproducts is valid in the country to which they
were originally shipped and at the factory. If you think there are problems
with your unit, please contact your dealer or the factory immediately.
Should your unit need to be repaired, contact the factory or your dealer
(distributor) for a return authorization. Freight to the factory or dealer
(distributor) is your responsibility. Return freight to you will be paid by the
factory or distributor.
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