Bryston l14BST Stereo Amplifier User Manual


 
Input:
The 14B ST has two inputs per channel, one
for a balanced source, and one for single
ended or unbalanced source. The BAL input
connector will accept either a 3 pin ‘XLR’ type
or a 1/4” Tip/Ring/Sleeve type. The positive (+)
terminal is pin 2 on the ‘XLR’ and tip on the
TRS. The input impedance is 15K ohms. The
input pins are gold plated. Input sensitivity is
selectable using the ‘INPUT’ slide switch. In the
BAL REG’ position 2 Volts in = 100 Watts at 8
ohms output. This is the recommended setting
when using Bryston preamplifiers or any pre-
amplifier having active balanced outputs. This
setting also produces the lowest amplifier noise
floor. The ‘BAL+6dB’ setting adds 6 dB of gain
to provide an input sensitivity of 1 Volt in = 100
Watts at 8 ohms output. This setting is primar-
ily for balanced outputs that are transformer
coupled, or other low level sources.
The UNBAL’ setting selects the gold plated
‘RCA’ type tip/sleeve connector. The input im-
pedance is 50K ohms. The output is in phase
with the input and the sensitivity is 1 Volt in for
100 Watts into 8 ohms output.
BRYSTON 14B ST MANUAL
Page 3
14B ST Rear Panel Connections:
Balanced Vs Unbalanced:
Balanced cable interconnects should be used
whenever possible, as they provide common
mode noise protection from external electrical
interference, and with active balanced out-
puts a 6 dB higher signal level flows in the ca-
ble.
The unbalanced cable interconnect is pro-
vided for preamplifiers without balanced out-
put. Unbalanced cables should be kept to 10
feet or less. Never use longer cables than
necessary, never coil excess cable length,
and run signal wires away from and never
parallel to A/C power or speaker cables.
Output:
Gold plated output binding posts provide dif-
ferent interconnect options. Stripped bare
wire up to 3 Ga. can be passed through the
hole in the binding post and held in place by
tightening the post knob. Additional tightening
pressure can be achieved using a coin in the
slots of the knob. Wire terminated with ba-
nana plugs, spade lugs, or pins are also ac-
commodated by the binding posts. Please ob-
serve correct polarity (Red/Black) when mak-
ing these connections. We recommend gold
plated connectors to prevent corrosion and
signal distortion. (Bryston has gold plated
5/16 inch spade lugs available). Speaker wire
should be kept as short as practical and
should never be terminated with connectors
that may become confused with A/C power
connectors. Speaker cables should be
dressed away from input and power cables,
and even each other when runs are long.
Remote Power Control:
You can turn the power amplifier on/off using
a 4 -12 volt A/C or D/C voltage using the 4
position screw terminal connector (see rear
panel diagram page 4). Insert the 4 -12 volt
wire into the input labeled ‘IN’ (polarity is not
important) and then place the ‘Ext
Trig’ (external trigger) switch into the
‘Rem’ (remote) position. The power amplifier
will now power on and off when the control
voltage is applied or removed.
The connector positions labeled ‘OUT’ can be
used to power another amplifier in sequence.
The 4/12 volt control voltage does not appear
at the ‘OUT’ terminals until after the 14B has
completely powered up so this allows se-
quencing of your power amps without large
turn-on surges.
WHEN THE ‘EXT TRIG’ IS IN THE ‘LOCAL’ POSITION THE 14B WILL IGNORE THE 4/12
CONTROL VOLTAGE AND WILL POWER-UP ONLY WITH THE MANUALLY ACTIVATED
FRONT PANEL ‘ST’ POWER SWITCH.