Bryston bp 1 owners manual

Page 2

BPI PREAMPLIFIER

LOW FILTER

The inflection point of the rumble filter has been set at 3 I .7Hz to correspond to the lowest signal
frequencies likely to be found on LP phonograph disks. The filter has a gradual slope of 6db per octave
below this frequency to avoid transient overshoot. ringing and phase anomalies. The warp frequencies
on LP phonograph disks are confined almost exclusively to the area of 2 to 5 Hertz and this range is
attenuated by an average of 20dB, or a power factor of IOO, to prevent overload and intermodulation
distortion effects in the low frequency drivers of your loudspeakers. The low filter is active in the IN or
depressed position.

VOLUME CONTROLS

Each channel is equipped with its own volume control and thus no balance control is provided.

PHONO INPUT CAPACITANCE LOADING SWITCH

This switch, located inside the BPI, is comprised of a six element DIP (Dual In Line) switch and six high
precision polystyrene capacitors to add the correct amount of capacitance across the phono cartridge to
ensure accurate performance. Each switch adds in one capacitor. As each capacitor is switched in the
total capacitance increases cumulatively. Switches l to 3 add capacitance to the LEFT input, and switches
4 to 6 add capacitance to the RIGHT input. Any or all of the DIP switches may be activated (placed in
dae ON or CLOSED position) at one time or, if all switches are off (open), then no capacitance is placed
across the phono inputs.

LEFT RIGHT LEFT RIGHT

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Refer to information supplied with your phono cartridge to determine the correct amount of capacitance.