Summary of the content on the page No. 1
~NALOG AND DIGITAL PRODUCTS
S-SERIES
BIAS LEVEL
I I
04 40
0
O~
~0
01 10
KSA-100S / 200S/300S OWNER’S REFERENCE
Summary of the content on the page No. 2
INTRODUCTION Thank you for your purchase of the KRELL KSA-100S/200S/300S power amplifier. These amplifiers represent the latest evolution in amplifier technology, matching unprecedented performance with convenience not obtainable from most high performance audio designs. Throughout this Reference we will refer to all three of the amplifiers as KSA. All three amplifiers operate identically, while their sonic characteristics, specifications, and dimensions vary. Specific differences will be descri
Summary of the content on the page No. 3
TABLE OF CONTENTS 4 UNPACKING 5 LOCATION AND REMOTE TURN-ON 6 CABINETRY AND AC POWER CONSIDERATIONS 7 AMPLIFIER FEET AND REMOTE MASTER/SLAVE CONNECTIONS 9 INPUT AND OUTPUT CONNECTIONS 12 AMPLIFIER OPERATION 13 TURN-ON DESCRIPTION 14 SYSTEM NOISE 15 BIAS LEVEL METER 16 FRONT PANEL METER BUTTON 17 REMOTE CONTROL FUNCTIONS 18 PROTECTION CIRCUITRY AND TROUBLESHOOTING STEPS 20 QUESTIONS AND ANSWERS 22 SPECIFICATIONS 23 WARRANTY AND SERVICE INFORMATION PAGE 3
Summary of the content on the page No. 4
UNPACKING NOTE: Due to the extreme weight of the KSA amplifiers, it is strongly advised that unpacking and placement is completed by at least two individuals. 1. Open the box. 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. Pull the foam piece from the exposed end of the amplifier. 5. Roll the amplifier carefully onto its handles and remove the second piece of foam. Th
Summary of the content on the page No. 5
BASIC INSTALLATION LOCATION Place the KSA on a firm level surface away from excessive dirt or moisture. When using custom racks or cabinetry, keep in mind the weight and ventilation requirements for these amplifiers. Ideally the amplifier should be placed as close to the speakers as possible. It is preferable to run long balanced interconnect cables to the amplifier and keep speaker cable length to a minimum. Speaker cable adds impedance to the load the amplifier must drive, regardless of the ca
Summary of the content on the page No. 6
BASIC INSTALLATION CABINETRY CONSIDERATIONS High bias amplifiers dissipate much of the power they consume in heat. Because the KSA- 100S/200S/300S utilize Sustained Plateau Biasing, they remain cool when not in use. When the KSA is in use, it can become quite hot. Therefore, the KSA should be installed in a location that provides unobstructed ventilation. If you must install the unit on shelves or in a cabinet, extra ventilation may be necessary. This often can be accomplished with cabinet shelf
Summary of the content on the page No. 7
BASIC INSTALLATION AMPLIFIER FEET The feet on the KSA can be used in several different ways. They are made from machined Delrin and are supplied with separate threaded rubber bottoms. The rubber bottoms can be screwed into the feet for protection of fragile surfaces such as hardwood floors or furniture. For use on rugs, we recommend using the feet without the rubber bottoms. KSA feet can also accept the KRELL AMDs (Acoustic Mass Damper). The AMD is a type spiked foot that threads into the botto
Summary of the content on the page No. 8
BASIC INSTALLATION 4. Connect additional amplifiers as described in step 3. 5. When the cables are all in place, point the remote control at the amplifier designated as Master and press the Power button. The amplifiers will all turn on at the same time. The meter display for each amplifier may vary. Manually change the meter display via the front panel until all of the meters match. The amplifier will remember the meter setting when cycled On/Off via the remote control or front panel switch. If
Summary of the content on the page No. 9
CONNECTIONS 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 STAND-BY mode. The wiring to and from the amplifier, and all components in, general, should be arranged in a neat, organized manner. Specifically, AC wires should be separated from audio wires. This practice avoids hum or other unwanted noise from being induced into the system. 1. Connect the speaker cables to the am
Summary of the content on the page No. 10
CONNECTIONS The pin assignment for the XLR is: pin 1 = shield (ground) pin 2 = non-inverting input (hot) pin 3 = inverting input NOTE: The RCA center conductor for each channel is wired in parallel with pin 2, the non-inverted input. Only one of these inputs should be connected to a preamplifier. Do not attempt to use the single-ended and balanced inputs simultaneously. 3. Insert the AC power cord into the receptacle located on the back of the KSA. Insert the other end into the wall AC receptacl
Summary of the content on the page No. 11
CONNECTIONS LOUDSPEAKERS KSA AMPLIFIER R L PAGE 11
Summary of the content on the page No. 12
OPERATION AMPLIFIER OPERATION Understanding the ’operation of the amplifier is very easy. Equally important is an understanding of the care that should be exercised when operating the system as a whole, in relation to the enormous power output of the KSA. Simple mistakes, such as switching between active sources without muting the preamplifier output, or bumping/miscuing a cartridge, can generate large transients at low frequencies. With this type of transient the KSA can generate enough power t
Summary of the content on the page No. 13
OPERATION DESCRIPTION OF TURN-ON SEQUENCE When turning on the system, the amplifier should always be last. The KSA On/Off switch is part of a multi-level turn-on circuit that goes through several steps of protection. Upon turn-on, the amplifier’s outputs are not connected to the speakers. After the protection circuits have determined that the unit has completely stabilized, the speaker relays will engage. You will hear a click at this point. The LED’s in the bias meter will start at the highest
Summary of the content on the page No. 14
OPERATION SYSTEM NOISE CONSIDERATIONS AC grounding often becomes critical when connecting high performance audio gear. When mixing and matching audio components, each with their own ground potentials, a low frequency hum can become present in one or both speakers. This can often occur when introducing a new component into the system. If there is a low frequency hum coming from the speakers when the KSA is connected into the system, follow these simple trouble-shooting steps: 1. Check all of the
Summary of the content on the page No. 15
OPERATION BIAS LEVEL METER The KSA amplifiers utilize Sustained Plateau Biasing, a proprietary KRELL design. The Bias display meter on the front panel of the amplifier displays which level of bias the amplifier is utilizing. Unlike sliding bias designs, Sustained Plateau Bias only changes level when the demand situation relative to input and source material changes. The signal passes through a section called an Anticipator circuit. Once the level of bias is determined by the Anticipator circuit,
Summary of the content on the page No. 16
OPERATION FRONT PANEL METER BUTTON A small button beneath the Power button on the front panel controls Bias Meter display illumination. When engaged, the meter display will no longer indicate bias levels; only the Blue pilot LED will be visible. The Bias Level meter can also be turned on or off via the remote control. PAGE 16
Summary of the content on the page No. 17
OPERATION REMOTE CONTROL FUNCTIONS The KSA-100S/200S/300S are the first high performance amplifiers to utilize remote control functions. The amplifiers can be switched on or offand the meter function can be changed from your listening position via the hand- held remote control. The KSA remote control duplicates the front panel switches on the amplifi- ers. The Power button will turn the amplifier on and off, while the Meter button will choose between a full bias meter display or no bias LED illu
Summary of the content on the page No. 18
OPERATION PROTECTION CIRCUITRY There are no fuses in the KSA. The amplifier is protected by a series of non- intrusive, opto-coupled 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 speakers caused by other defective components, faulty wiring, mish
Summary of the content on the page No. 19
OPERATION Should the amplifier turn off when either output cable is connected, the problem is cable or speaker related. Check to make sure there are good mechanical connections on the speaker cabling and there are no frayed ends or wires shorting the output terminals together. Have your speaker cables checked and repaired if necessary by your dealer before proceeding. 3. If the amplifier turns on normally with only the speaker cables connected to the output, turn the amplifier off and reconnect
Summary of the content on the page No. 20
QUESTIONS AND ANSWER Q. Should I leave the KSA on at all times? A. Because of Sustained Plateau Bias, the KSA can be left on at all times without fear of damage, excessive heat or excessive power consumption. The KSA amplifier however, is designed to be turned On/Off, and can do so without degradation. The amplifier will work at full performance within minutes of turn-on. Q. When I push the power button on the front of the KSA, the amplifier doesn’t turn on. What should I do? A. Check the input
