Krell KST-100 Owners manual

A, INTRODUCTION
Thank you for your purchase of the KRELL KST-100 poweramplifier. This amplifier represents the latest
evolution ~n amplifier technology and incorporates many
innovative design features.
To obtain the best performance from. your KST-100,
This Owner’s Reference is divided into several sections,
each designed to perforn}_, a different function. As you .read through this Owner s Reference y~ou will becgme
19etter acquainted with the features and functions tlaat
make the-KST-100 a superb value. A Question and An­swer section is also included where answers to common
questions are provided. Should you have any questions or suggestions pIease feel free to contact your authorized
dealer or the KRELL staff for assistance. In the unlikely, event that your.KST-1.00 should require
service you will be pleased_ to k~now that it is backed by a c.omprehensive Customer batistaction policy and one of
tlae most advanced service facilities in the industry.~t~or
detailed information on the terms and conditions ot ser-
vice, please consult your warranty .registration card, your
authorized KRELL Dealer or Distributor.
2
TABLE OF CONTENTS
4
9
10
11 REAR PANEL DESCRIPTIONS
12 QUESTIONS AND ANSWERS
14 SPECIFICATIONS
UNPACKING AND ASSEMBLY
BASIC INSTALLATION AND OPERATION
5
6 INPUT AND OUTPUT CONNECTIONS
AMPLIFIER OPERATION
8
PROTECTION CIRCUITRY
MONAURAL CONVERSION OPERATION
15 WARRANTY AND SERVICE INFORMATION
3
B. UNPACKING AND ASSEMBLY
NOTE: Do to the weight of the KST-100 it is s.trongly
advised that unpacking and placement is completed by at least two individuals.
1. Open the box on one end.
2. Fold back the flaps on all four sides of the box and carefully roll it over on to the exposed end.
3. Pull the box straight up and off exposing the foam
packing material.
4. Lay the foam container down on the floor and pull off the top section.
The following items will now be visible:
1 1 1
4
NOTE: If any of these items are not included please contact your authorized dealer immediately for assis-
tance.
5. Pull the amplifier out of the remaining layer of foam.
6. Remove the plastic bag from the amplifier.
NOTE: Save allpacking materials. If you must ship. your
KS.T-100 in the future, repack, the unit in its original
packaging to prevent transit damage. CAUTION: Do not connect the power cord into the AC
mains before completing the Installation section.
KST- 100 stereo amplifier Warranty card AC power cord
Rubber bottoms
4
C. BASIC INSTALLATION AND OPERATION
1. Place the KST-100 on a firm level surface away from
excessive dirt or moisture. Ideally the amplifier should be placed as close to. the speakers as possible. It is always preferable to run long_ interconnect cables to the amplifier
and keep speaker calSle length to.a minimum= Speal~er cable does add an impedance at the output ot the ampli-
fier, regardless of the cable’s g.uage. AIIKRELL amplifi­ers wilI drive the lowest impeclanc, es with ease. When
impedance is added, the amplifier s power is literally wasted in driving cable. Long speaker cables reduce the
maximum power that can be delivered to the speakers.
2. Amplifiers dissipate much of the power they consume
in heat. The KST-1~00 should be installed in a location that provides unobstructed ventilation. If you have t.o install the unit on shelves or in a cabinet, extra ventilation
may be necessary. This can be accomplished with "whis­per"-type fans. Consult your dealer f-or assistance.
Generally, with the front and rear of a cabinet open, 2-3 inches of clearance on each side and 8 inches of clear-
ance above the amplifier should provide adequate venti­lation.
The exact dimensions for the KST-100 are in the Specifi-
cations Section below.
3. The KST-100 should have a dedicated line and should
only be operated with the power cord supplied. Use of
other power cords may damage the ampIifier or void its
warranty. Please consult KRELL or your dealer BEFORE using a~ny devices designed to alter or stabilize the AC
pgwer tor the KST-100. If you have any questions about placement or AC power conditions please consult
KRELL.
4. The feet on the KST-100 can be used in several differ-
ent ways. They are made from machined Delrin and are
supplied with separate threaded rubber bottoms. The rubber bottoms can be screwed into the feet tor protec-
tion of fragile surfaces such as hardwood floors or furni-
ture. For use on rugs, we recommend using.the feet wi.th-
out the rubber bottoms. KST-100 feet can also accept tlae
KRELL AMDs (Acoustic Mass Damper). These improve
the amplifier’s sonic performance in most installations.
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D. INPUT AND OUTPUT
CONNECTIONS
CAUTION: When making connections to this component
or any other, make sure the power amplifier is OFF and the preamplifier is in the MUTE or STANDBY mode.
1. Connect the speaker cables .to. the output terminals of the amplifier. Tile KS~T-100 utilizes two sets of parallel 5-w~y binding posts tor the left and right channels. This
confi~guration makes cable connections and bi-wiring simple.
NOTE: The binding, posts are of the highest quality but will break if over.tigla.tened. In.se.rt wire or spade lug into the connector anO tighten until there is no movement from the cable.
CAUTION: Make sure all cable terminations are of the highest quality, free from frayed ends, shorts or cold solder joints.
2. Connect the interconnect cables from your preampli­fier to the input of the KST-100.
The wiring to and from the amplifier, and all components in general, should be arranged m a neat, organizedman-
net. Specifically_, AC wires should be separated from audio wires. Ttiis practice avoids hum or other unwanted
noise from being induced into the system. The KST-100 has balanced and Single-ended i,np.uts. The
balanced inputs use 3-pin XLR connectors anti the
single-ended inputs use standard RCA connectors.
CAUTION: Use only one input to the amplifier at a time.
The KST-100 is shipped with shorting pins in the XLR inputs. These pins sliould remain in the XLR inputs if you are operating the KST-100 in the single-ended mode.
.When t.he shortingpin is inserted, pin 1 and pin 3 are
shorted together. Tile shorting pins must be removed to connect the KST-100 for balanced operation.
6
Thepin assignment for the XLR is:
pin _1-= shield (ground) p!n 2 = non-inverting ~nput (hot)
p~n 3 - inverting input NOTE: The RCA center conductor for each channel is
wiredjn, parallel with pin 2, the non-inv.erted input. Only one ot tlaese inputs should be connectecl to a preamplifier.
3. Insert the AC power cord into the receptacle located on
the back of the KST-100. Insert the other end into the
wall AC r_.eceptacle. (Refer to section C, Basic Installa-
tion and Operation, for AC power requirements)
.
7
Eo AMPLIFIER OPERATION
1. Push the black breaker type switc.h on the front of the amplifier to turn it on. The LED in the switch will illumi­nate.
When turning on the system, the a _m, plifier should always be last. Upon turn-on, the amplifier s outputs are not
connectedto the speakers. After the protection circuits have determined that the unit has completely stabilized, the.speaker relays will be engaged. You wilI hear a click at th~s point. The amplifier is now ready to use. The amplifier will be at temperature and sound its best after approximately 30 minutes.
2. With the preamplifie.r in the Mute position, or volume control fully attenuated, select a source. Turn the volume control up to your desired listening level.
3. Understanding the operation of the amplifier !s very easy. Equally important is an understandi.ng of the care
that should be exercised when operating the system as a whole, in relation to the enormous power output of the KST-100. Simple mistakes, such as switching between active sources without muting the preamplifier output, or
bumping/miscuing a cartridge., can genera~te large tran.-
sients at low frequencies. With this type 9t transient the
KST-100 can generate enoughpower to damage most loudspeakers. All switching of sources shouldbe done
with the preamplifier level either muted or fully attenu-
ated. Inputs to the amplifier should not be changed while
the amp-lifter is on. NOTE: Care must b.e taken when setting high playback
levels. Because of their tremendous reserve of-clean power, KRELL amplifiers safely drive speakers to higher
sound pressure levels than other amplifiers. This also .
means driving the speakers to their fimit. Always turn the
level down at the first sign of distortion. When turning the system off, the amplifier should
ALWAYS be first. This avoids the possibility of a turn­off transient from some other component getting to the speakers.
8
E PROTECTION CIRCUITRY
There are no fuses in the KST-100. The amplifier is protected by a series of non-intrusive, opto-c_o, upled
circuits that constantly evaluate the amplifier s operation. Appropriate protective action exists for DC conditions,
short circuit, oscillation, AC power anomalies, high
ground resistance and out-of:phase ground. Collectively the protection circuitry is designed to avoid damage to
the amplifier or speal~ers caused by othe.r defective com­ponents, faulty wiring, mishandling of tlae system or
amplifier failure. When the protection circmt is engaged,
the a.mplifier will shut off and short its output. After resolving either the input or output problem the amplifier
can be turned on. The amplifier also has a circuit breaker type powe.r
switch that protects it from excessive ACcurrent draw. Should the breaker shut off frequently or become difficult
to push ON contact your dealer or Krell Industries.
G. MONAURAL CONVERSION AND OPERATION
The KST-100 can be easily cgnverted into a 400 watt monaural amplifier. To switcla the amplifier to mono
follow these instructions.
1. Remove the topcover from the amplifier via 8 topcover
screws.
2. Find the toggle switch located at the rear of the ampli­fier mounted on the circuitboard.. Mo.ve the toggle switch
over to the Mono setting printecl on tlae circuitboard.
3. Reinstall the topcover and the 8 topcover screws.
OPERATION
1. The input of the KST-100 in Mono operation is the
Left channel input only. Connect the Left output of your preamplifier to the Left
channel input of the ~lesignated left channel mono ampli­tier. Connect the rig~ht output of your preamplifier to the
left channel input ot the designated right channel mono
amplifier.
2. The output of the KST-100 in Mono operation is the positive outside binding posts of each channel. The inside Black binding post of each channel in mono is not opera­tional.
Connect the left and right channel outer binding posts on each amplifier to the loudspeaker.
NOTE: Pay careful attention to the labeling on the. backpanel of the KST-100 when making input anti output
connections. Connecting this amplifier i~or monaural operation can become confusing.
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H. REAR PANEL DESCRIPTIONS
INPUTS: Balanced via 3 pin XLR connector
Single ended via RCA connector
XLR PIN CONFIGURATION p!n 1 Shield (ground)
p!n 2 Non-inverting or 0 degrees (hot) p~n 3 Inverting or 1-80 degrees
OUTPUT: Two pairs of five-way binding posts in parallel,
per channel OTHER:
Standard AC receptacle 20 amp circuit breaker type power switch
OPTIONS: Black Faceplate
11
I. OUESTIONS AND ANSWERS
Q. Should I leave the KST-100 ON at all times? A. Althou.gh you could leave the KST-100 ON at all
times without fear of damage to the amplifier, we recom-
mend 30 minutes of warm-up_ before critical listening and
switching the amplifier off when not in use.
. When I push the power switch on the front of the
~
ST-100, the amplifier doesn’t turn ON. What should I
do? A. Unplug the amplifier from the AC receptacle and
remove ttie input from the amplifier. Check the output
connections,, then plug the amplifier .back in. Push the
power .switch on the front panel. If the power switch resists being turned ON or shuts OFF once engaged,
unplug the unit and call your dealer or Krell industries. t~. When I turn the amplifier on there is a loud hum
rough the speakers. There was never a hum before the
KST-100 was in the system. What should I do?
A..O. ften when a new component is introduced into an auclio system a hum may 15ecome present. This is often caused by_ a ground loop in the system. Try putting a 3
prong to 2 prong AC adaptor (cheate.r plug) on the power cord, lifting the ground from the unit. This should
make the hum disappear. If not, try another adaptor else­where in the system.
NOTE: Always keep one major audio component grounded.
NOTE: Even though the ground is lifted from the power amplifier, it .is still grounded via the interconnect cables throughout the rest of the system.
Q. Can I use special audio power cords on the KST-100? A. You can experiment with special power cords as long
as they ar, e grounded on both ends and meet the amplifier s I5 amp power requirement.
12
Q. After the amplifier is playing for about one hour it
becomes very hot. Is this normal?
A. Yes. Due to the design of the KST-100 it will become
quite warm when driven hard. If the amplifier should have a severe temperature inbalance between the left and fight channel, unplug the unit and call your authorized dealer or Krell.
Q. I tried a ne.w. preamplifier in my audio system and
when | turnecl ttle unit on tlae KST-100 shut off. Is the amplifier defective?
A. More than likely the amplifier is not defective. When
connecting components you should always keep the amplifier off. The amplifer sensed a bad input signal and
slaut off, protecting itself and the speakers.
There also could have been a bad cable connection or excessive DC offset coming from the output of the. pre­amplifier. Before turning t, he amplifier on, check tlae
input cables. If that doesn t help, bring the preamplifier to the dealer for testing.
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¯ I. SPECIFICATIONS
KST-100 GAIN
26dB,
SIGNAL-TO-NOISE
102dB unweighted
THD
1K at 8 ohms
less than. 1% 20K at 8 ohms
less than .3%
INPUT IMPEDANCE
47,000 ohms(47K)
INPUT SENSITIVITY
1.5 volts for 100 watts out
OUTPUT IMPEDANCE
¯ 1 ohms
OUTPUT VOLTAGE
80 volts peak to peak 8 ohms
OUTPUT POWER
All readings are continuous output power, per channel
ohms 100 watts ohms 200 watts ohms 400 watts ohm 800 watts
DIMENSIONS
18.0" WIDE
14.8"
6.5" HIGH with feet
SHIPPING WEIGHT
60 pounds
DEEP with handles
14
K. WARRANTY AND SERVICE INFORMATION
There are no user-serviceable parts inside the KST-100. The KST-100 has a limited warranty of .five years parts and labor. Return freight is includedin the warranty.. The warranty, pe~od, begins on ~the date of purchase and is
activated witla the return ot the enclosed Warranty Card and a copy of the Sales receipt. Please return the war-.
ranty card immedia.tely.after successful installation anti
operation are completecl.
The warranty for Krell products is valid ~nILq~ in t.he coun­try to which they were originally shipped a.nd at the fiictory. If you think there are problems witla your unit please contact your dealer, distributor or the factory immediately.
Please do not return, any unit to KRELL for repair with-
out first calling to cliscuss the problem and to ot~tain a
Return Authorization number.-Freight to the factory or
distributor is your responsibili.ty. R.~tum freight to you will be paid by the factory or dlstrit)utor.
Any unauthorized .updates or modifications performed to the unit will void tlae warranty.
15
45 CONNAIR RD ORANGE, CT 06477 SALES 203-799-9954 FAX 203-799-9796
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