Bricasti Design MC1, Руководство пользователя

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Design Overview
There are 4 basic sections to the MC1, the digital input section, and the left and right analog sections, and the front
panel:
Digital Input Section:
This is located in the center of the unit, provides 5 transformer isolated digital inputs, are selectable from
the front panel, and has its own linear power supply. This means that the digital processing section is
isolated from the analog sections, providing excellent low noise performance and eliminates digital noise
from entering the analog chain via the power supplies and ground plane. This section features an Analog
Devices Sharc DSP that is used to run the front panel and general operations of the MC1, to control and
synchronize the DDS clocking on each channel, and to provide a selection of our own over sampled anti-
aliasing filters.
Analog Output Sections, Left and Right:
These are identical and are laid out as mirror images of each other to fit with the over all symmetrical
industrial design of the MC1. Both are independently powered by their own linear power supply insuring
clean double regulated low ripple power and isolation from any digital switching noise from the digital
supply.
Each section has its own Analog Devices 1955 DAC, coupled with a dedicated DDS clocking circuit
located millimeters away from the DAC, assuring extremely low jitter and minimal trace length for the
clock signal. As both boards have their own clock, precise clock synchronization of the left and right
boards is handled by the Sharc DSP on the main digital processing board.
The next stage, at the analog out of the converter for the gain and filter sections there is a fully differential
analog design with fast high slew rate analog operational amps. This is followed by 2 transistor designed
output buffer sections, balanced and unbalanced, each separately buffered and isolated. The balanced
output level as shipped is set with a fixed resistor at +16.3 dbm or 5V RMS. For custom level matching, an
internal the jumper on the board can be moved to engage a precision adjustable potentiometer. This
adjustment is set from the rear panel screw near the XLR connector. When the potentiometer feature is
engaged the level is adjustable from +8 to +23 dbm and can be referenced to a fraction of a db to match any
setup.. The unbalanced is set to typical levels of 2V RMS (+8dbm) by precision resistor values on the
board.
Typical circuit boards in most products are made from FR4 fiber glass. But, the MC1s analog boards are
made from a ceramic substrate used in RF applications. This material has excellent very high frequency
impedance characteristics, and was chosen for use in the MC1 to yield an open and clear sound and to
allow its very high slew rate audio circuit design to perform at optimal levels.
Trigger In:
On the rear panel the MC1 has a stereo connector (Tip/Ring/Sleeve) for triggering the MC1 into standby
mode from an external device like a preamp and for optional external remote control with the MC1 remote.
Sleeve is connected to chassis ground, Tip/Ring is the input +/-. The MC1 will go into standby when it has
a positive 5V or 12V DC voltage between tip/ring.
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