KBL & KPA OWNERS’ MANUAL
45 ConnairRoad Orange,CT06477-0533, USA KBL & KPA OWNERS’ MANUAL INTRODUCTION Thank you for your purchase of a new KRELLpreamplifier. This Owners’ Manual covers both the KBL and KPA preamplifiers, as they have been designed to be companion pieces and can be utilized in varying combinations. For each user there will be information that does not pertain to their specific situation. Therefore, in the interest of clarity, details relating to different combinations are presented in well-defined sections.
D. Installation: 1. 2. 3. 4. 5. 6. 7. 8. Caution Connector Details Connector Termination Types Cable Requirements for Inputs and Outputs Setting of Internal Switches Unit Location Guidelines and Installation Connection of Inputs and Outputs Turn-on of the Preamplifiers E. Operation: 1. KPAFunctions 2. KBLFunctions F. ,W~rranty ~nd Service Information G. Termination A. SERIAL Drawings NUMBERS & FACTORY-SHIPPED KBL preamplifier serial factory set-up for operation.
These units are the current state-of-the-art. No compromisewas allowed in their design. Details concerning their technical performance are covered in more detail below, A second important consideration was to introduce the programmable concept employed in our current KSA/KMA amplifier line into our preamplifier line. A single KBLand KPAare used for stereo operation. A second unit of either can be added to achieve dual-mono, fully balanced operation.
Both preamplifiers have innovative operational features. The KBLhas two balanced inputs and one set of balanced outputs in addition to four singleended inputs and one set of single-ended outputs. This allows one KBLto accommodatebalanced line sources and amplifiers, which Krell believes to be the standard for high-end audio gear. Therefore, it is only necessary to purchase a second KBLto achieve dual-mono, fully balanced operation. The KBLinput labeling is a departure from the norm as well.
1 KP~without _vower supvlv preamplifier chassis DCjumper cable (KBL to KPA) "T" shaped Allen driver Owner’s Manual 1 each: 1 KPA with~owersu~pl_v 1 each: preamplifier chassis KPApower supply with ACand DCcables attached DC jumper cable (KBLto KPA)*not used when the dedicated KPAsupply is used* "T" shaped Allen driver Owner’s Manual Inspect the unit(s) and power supply(s) for damage. If any is evident, or some of the accessories are missing, contact your dealer or the factory immediately.
2. Connector Details This section, with sections 3 & 4 below, presents all details necessary to make or modify cables for use with all combinations of the KBLand KPA. After reading these sections, check all the cables you intend to use to make sure they are appropriate for your installation. a..Gener~:[ .. Information Different configurations of the KBLand KPArequire different cable terminations. The connector assignments for the KBLand KPAinputs and outputs are given. b. KBLConnector Assignments: c.
All Krell Industries and Krell Digital products use this pin-out for inputs and outputs. c. Balanced RCATerminatiom uses two-conductor coaxial cable: See Drawing1 at the rear of the Manualfor details. 1 pr. of RCAconnectors are used on each end of the cable with this termination; 4 prs. total are used if this termination is used at both ends.
Read the portions of sections a and b below that pertain to your system for the specific cable terminations required. If you are adding to your system you may need to change some cable terminations to take full advantage of dual-mono, balanced operation.
Please read this section to determine if you have the need or desire to change the internal switches. a. KBLStereo~D~al-M0n0 ~witches These switches are used to change the KBLbetween stereo and mono operation. Their most commonuse is to change an existing KBLfrom stereo to dual-mono when installing a second KBLfor dual-mono. There is one double-toggle, two-position dip switch between the input connectors for B-1 (SW6) and for B-2 (SW7); there is a third near balanced output connectors (SW8).
Four inches clearance should be allowed above the top of either the KBLor KPA. Only a small amount of clearance is needed on the sides. Four to six inches clearance should be allowed at the rear of either unit to provide for cables. 3. The units can be stacked. KPA(s) should be placed on the bottom with KBL(s)on top. KPA(s) are sensitive to induced hum from motors or power supplies. In general, they should be located at least one foot from other components (with the exception of the KBL).
d. Power Supply Installation 1. 2. 3. 4. Place the power supply(s) in location. Connect the DCcable(s) from the supply(s)to the preamp(s) Plug the DCjumper between the KBL(s) and KPA(s). Donot plug the ACconnector(s) into the mains at this time. 7. Connection of Inputs and Outputs All source componentsand amplifiers should be off at this point. Whenconnecting balanced components to the KBLvia RCAconnectors be sure to maintain proper polarity of the non-inverted and inverted inputs.
b. Connection of KBLRecord Outputs There are two Record outputs which receive the signal from the input chosen on the Select switch for sending to two tape recorders. The two outputs are wired in parallel and have no relation to any of the inputs. Makethe connections between the Record outputs and tape recorders at this time. c. Connection of the KBLMain Outputs There are two sets of Main outputs: one set single-ended on RCAs’, one set balanced on XLRs.
E. OPERATION 1. KPAFunctions Use the Select switch to choose between two different cartridges or tonearms. If the two inputs are not the same type cartridge be sure to change the gain with the Gain switch to avoid any overload conditions. See section c below. b. LQading Use the Loading switch to adjust the impedance load for the selected cartridge input. This can be adjusted while listening with the KBLor preamp volume at normal levels without causing damage to any other component.
This switch can be operated while listening to the KPAat normal levels without risk of damageto the preamplifier, amplifier(s) or speakers. Its setting is a matter of personal taste. f. RIAAAdjustment. 20 KHZ Use this switch to make subtle adjustments to the high end of the RIAA equalization curve. The LEDindicator will illuminate when the switch is in any position other than flat.
Input B-2 on the Monitor switch uses only Therefore, if you are feeding a balanced signal dB difference in level between B-2 on the Monitor switch. The level on the Select switch the non-inverted signal. into B-2, there will be a 6 Select switch and on the will be the higher one. Note: Be careful not to create a feedback loop between the KBLan tape recorder. This can happen by selecting the tape recorder output on the Select switch and having the tape recorder set on "source".
Whenthe control is turned clockwise the left channel is attenuated; when turned counterclockwise the right channel is attenuated. The LEDindicators may illuminate at high listening levels. This indicates that a level difference exists between the left and right channels at that moment. This can be disregarded unless there is an audible channel imbalance. 2.
Balanced RCA [o RCA cable wiring Drawing I, Termination (WHITE) non-inverting: diagram c. solder to white RCAcenter pin ~,. \\(BLACK) inverting:L~..., solder to red RCAcenter \\ ELD wire): solder to white non-inverting (SHIELDwire): solder to red inverting RCAcase RCAcase solder extra wires to shield for RCAground solder extra wires to shield for RCAground \... (SHIELDwire): solder to red inverting RCAcase ~ .//~ / (SHIELD wire): solder to white non-inverting RCAcase .. ...
Balanced RCALo XLR cable wiring diagram Drawing 2, Termination d. BA L A NCED R CA END (WHITE) non-inverting: ~ solder to white RCAcenter pin BLACK)inverting: solder to red RCAcenter pin ,(SHIELD wire): ,~C.
Balanced KPA cable wiring diagram Drawing 3, Termination e. B~I L A NCEDKPA END (WHITE) non-inverting: solder to RCAcenter ., \’" (,,BLACK) inverting: solder to RCAcenter pin "’~ (SHIELDwire): solder to non-inverting / : (SHIELDwire): solder to inverting RCAcase RCAcase 1/ / solder extra wires to shield for RCAground solder extra wire to shield For ground (Keep seperate from RCA case) to Turntable ground i f necessary.
