B and K PRO-10 Owners manual

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 page 9

Tape Monitor Loop 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. They help to maintain acoustic feedback into the

amplifier at a minimum. They also provide a measure of protection

against scratching any surface the unit might be resting on. Do not

alter or remove them.

• Do not stack anything on top of the preamplifier (processor,

source...etc.).

Page 3

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. In order to obtain maximum performance from this
unit, Please read these instructions very carefully.

Features

FET loading - Maximizes linearity and minimize noise.
Wide bandwidth - Assure clear reproduction with all styles of music.
Polypropylene

film capacitors - RIAA accuracy typically within ± .2 dB through the use of polypropylene

film capacitors. This produces a transparent sound with highly accurate musical timbre.
Volume control - From a single precision attenuator. Accuracy of volume attenuation is

within .1 dB from channel to channel.
1% Metal Film resistors - Low noise resistors for better sound and a greater degree of

repeatability.
Also: Direct output capability

All discrete predriver circuitry

Premium gold-plated connectors

Separate source and record selectors

Balanced outputs standard

Page 4

Front panel view

1. Record selector knob

2. Source selector knob

3. Tape monitor button

4. Direct bypass button

5. Power switch (mute switch)

6. Headphone jack

7. Power on LED

8. Balance knob

9. Volume knob

10. Mono/Stereo selector button

Page 5

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.

TAPE
MONITOR - The tape monitor switch allows the tape deck connected to the tape monitor

inputs (TMON IN) to be routed to the processing circuitry and then to the
preamplifier’s output connectors (PRE AMP OUT) independent of the position
of SELECT. The input signal sel ected via SELECT remains valid but is
overridden while the TAPE MONITOR switch is in the ON position (switch
pushed in). Turning the TAPE MONITOR off (switch pushed out) restores the
input signal determined by the SELECT position.

DIRECT
BYPASS - The DIRECT BYPASS switch selects the active or passive mode. In the active

mode (switch out) the selected signal is processed through a 20 dB DC
coupled amplifier. The passive mode (switch in) bypasses the gain stage of
the preamplifier.

POWER
SWITCH - The power switch is actually a mute switch. This switch changes the mode of

the preamplifier. With the switch on, LED illuminated, the signal is passed
from the source to the amplifier. With the switch off, LED off, the source is
passed to the headphone jack.

HEAD­PHONE - Stereo headphones having a standard ¼ inch binaural plug can be connected

to the headphone output. The mute switch must be in the off position for the
headphone output to be enabled.

LED - Indicates which mode the preamplifier is in. When the LED is illuminated the

preamplifier passes the selected source to the outputs of the preamplifier to
the amplifiers. When the LED is off the preamplifier passes the selected
source to the headphone jack.

Page 6