Table of contents Safety precautions page 3 Introduction page 4 Front panel view page 5 Front panel description page 6 Record page 6 Select page 6 Tape Monitor page 6 Direct Bypass page 6 Power Switch (Mute) page 6 Headphone page 6 LED page 6 Balance page 7 Volume page 7 Stereo/Mono page 7 Back panel view page 8 Back panel description page 9 Balanced Preouts page 9 Page 1
Unbalanced Preouts Tape Monitor Loop page 9 page 9 Line Level Inputs page 9 Phono Inputs page 9 Phono Ground page 10 Power Connection page 10 Phono Stage Configuration page 10 MM/MC selection page 10 Capacitive Loading page 10 Resistive Loading page 11 Tables page 12 Block diagram page 13 Making the connection page 14 Troubleshooting page 15 Specifications page 16 Warranty page 17 Accessories Included : Power cord, Power supply, Owners Manual Page 2
SAFETY PRECAUTIONS PLEASE READ BEFORE INSTALLING • Turn preamplifier ‘off’ when plugging in or unplugging input and speaker cables!!! • When plugging in or unplugging interconnect cables running from source to preamplifier, always mute the preamplifier and rotate the preamplifiers volume control to minimum first. It is recommended that you turn the amplifier ‘off’ as well for this operation. • The PRO10 is equipped with raised feet so that continuous ventilation can be maintained.
Introduction Thank you for selecting B&K Components, Ltd.’s PRO10 preamplifier. The PRO10 is designed for the discriminating audiophile. The PRO10 is a DC coupled preamplifier that has been designed using all discrete circuit topology with a switchable head amp on the phono stage. Gold-plated premium connectors have also been utilized to minimize degradation in the signal path. The PRO10 has an external power supply that should be connected to an unswitched AC source.
Front panel view 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Front panel description RECORD - Controls which one of the six input pairs is routed directly to the record output connectors (REC OUT). The selected input signal bypasses the remainder of the preamplifier’s circuitry to provide the purest possible recording source. SELECT - Controls which one of the six input pairs is routed to the processing circuitry and then to the preamplifier output connectors (PRE AMP OUT). The signal made available at these connectors is used to drive the external power amplifiers.
BALANCE - The balance control is used to adjust the relative volume of the left and right channels. This affects the PRE AMP OUT connections and the headphone output. VOLUME - STEREO MONO - Turning the volume control clockwise increases the volume level, counterclockwise decreases the volume level. The stereo/mono switch selects the mode in which the incoming signals are processed through the preamplifier.
Back panel view 1. 2. 3. 4. 5. 6. 7.
Back panel description BALANCED PREOUTS - For use with balanced output cables when your amplifier has balanced inputs. The balanced outputs will help improve the quality of sound being reproduced by the amplifier when there is a long run between the amplifier and the preamplifier. Balanced connector cable end UNBALANCED PREOUTS - Standard RCA outputs to connect patch cables to amplifiers. RCA connector cable end TAPE MONITOR LOOP For connection of your tape recorder.
PHONO GROUND - For connection of your ground wire for phono use. POWER CONNECTION - For connection of the included power supply. ** Caution must be taken when connecting the included power supply. Do not force the plug as you may damage the pins inside the preamplifier. The plug is keyed so you can only insert it in one orientation. **NOTE - USE ONLY B&K COMPONENTS POWER SUPPLY. Phono Stage Configuring Select Moving Magnet (MM) or Moving Coil (MC) 1.
selector switch. 3. Trim the leads of the capacitors (one required per channel) to approximately _ inch. 4. Insert the leads into the CLOAD pin receptacles securely. Resistive Loading NOTE: The PRO10 is shipped from the factory with a 100 Kohm resistor installed and the phono stage MM configuration selected. This resistor should not be removed unless the resistive loading is being changed in accordance with the following guidelines. 1.
NOTE: You may not be able to attain the proper value resistor to fit you application, use the closest standard value you can find. Refer to the following table for more calculated values of MM Rc desired (ohms) 5K 20 K 35 K 50 K 75 K Ri calculated (ohms) Ri standard (ohms) 5.3 K 25.0 K 53.8 K 100 K 300 K 5.36 K 24.9K 53.6 K 100 K 301 K Refer to the following table for more calculated values of MC Rc desired (ohms) 25 45 75 100 125 Ri calculated (ohms) Ri standard (ohms) 30 68 171 403 2.1K 30.1 68.
Figure 1 Block Diagram Page 13
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Making the connection The diagram below shows a typical connection between the preamplifier and a B&K amplifier using the unbalanced RCA outputs. Note: The balanced button on the amplifier must be in the off (out) position. The diagram below shows a typical connection between the preamplifier and a B&K amplifier using the balanced XLR outputs. Note: The balanced button on the amplifier must be in the on (in) position. You may use either of these options to connect your preamplifier to the main amplifier.
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PRO10 Specifications Moving Coil Sensitivity (at 1kHz) .09 mV Moving Coil Overload (at 1kHz) 17 mV Moving Coil Load Resistance Variable Moving Coil Load Capacitance Variable Moving Coil (S/N A Weighted) 70 dB Moving Magnet Sensitivity (at 1kHz) .8 mV Moving Magnet Overload (at 1kHz) 225 mV Moving Magnet Load Resistance Variable Moving Magnet Load Capacitance Variable Moving Magnet (S/N A Weighted) 82 dB THD .02 % IM Distortion (SMPTE) .
Limited Warranty B&K Components Ltd., referred to herein as B&K, warrants your B&K equipment against all defects in material and workmanship for a period of five years from the date of purchase. This warranty applies only to the original purchaser and only to equipment in normal residential use and service.
