Grace 801R Owner's Manual

OWNERS MANUAL

MODEL 801R

REMOTE CONTROL

MICROPHONE PREAMPLIFIER

PO Box 204 Boulder, CO 80306 303.443.7454 fax: [phone]

http://www.gracedesign.com

Revision Ax January, 2000

© Copyright 2000, Lunatec LLC

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Overview

The 801R system consists of an 8 channel preamplifier chassis, a power supply chassis
and an optional RCU . The preamplifier chassis contains 8 audio amplifier PCBs, a
micro controller PCB and a front panel LCD display. The preamplifier chassis is
equipped with two Phillips I2C Bus connectors (D-sub 9 pin) and MIDI IN and OUT
connectors. The RCU contains identical micro controller and display PCBs and has a
single Phillips I2C Bus connector.

The preamplifier can be controlled by the RCU, via MIDI, or directly from its front panel.
The RCU connects to the preamplifier via I2C which provides a bi-directional data link.

Please Note: The 9pin I2C is a proprietary interface. It is not compatible with RS­232, RS-422, or any other 9 pin based serial protocol found in the recording studio
environment. Do not connect your Grace Design 801R or remote unit to any other
equipment!

The RCU can control more than one preamplifier. By connecting the remote unit to one
preamplifier and then connecting the remaining preamplifier units together with I2C
cables in a daisy chain fashion up to 8 preamplifiers can be connected together in a
system.

Grace Design 801R Remote Control Preamplifier

Preliminary user information

Operation

Front Panel Controls

Figure 1. RCU front panel

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The front panels of the RCU and the 801R preamplifier are identical and consist of the
following controls and indicators:

+48 Volt phantom power push-button
PHASE reverse push-button
GROUP push-button
PEAK Indicator Reset push-button
DATA Variable function rotary encoder with push-button
MODE select push-button
LCD display 64x240 pixels

Preamplifier Modes

Channel mode: This is the default power on mode. In Channel mode the rotary encoder
is used to select one of the eight visible channels for adjustment. When selected, the
settings for a channel can be adjusted with the +48, PHASE, or DATA controls. Pushing
the +48V or PHASE button toggles that function on or off on that channel. Pushing the
DATA control enters the Gain Adjust mode. While in Gain Adjust Mode the Gain
numeric display characters are highlighted and the rotary encoder adjusts the gain up or
down. Pushing the DATA control again exits the Gain Adjust mode and returns to the
Channel select mode. The bar graph meter at the right edge of each channel section is
a 15 segment peak meter that indicates preamplifier output levels from –35dBu to
+25dBu. Unlike the typical log scale level meter in a tape recorder, the 801R meter
represents level in a mostly linear dB scale. This allows for a meter range of 60dB and
useful peak output level information up to 4dB of the output clip point.

Note: You will notice that the meter ballistics will at first seem sluggish but this setup
actually provides more useful information about your peak levels and headroom status.

Meter Mode: In Meter mode the LCD displays bargraph level meters for up to 24
channels at a time. The DATA control is used to highlight an individual channel. If there
are more than 24 channels present in the system then the display “scroll” as the DATA
control is rotated. Pushing the DATA control when a given channel is highlighted
“zooms” to the Channel mode for channel parameter adjustment. Note: Meter Mode is
available on the RCU only and can only be accessed if more than one preamplifier are
connected to the system.

Setup Mode: The Setup mode displays a series of menus for various user setup options.
Step through the various setup screens by pushing the MODE pushbutton.

The Preamplifier ID: This field allows one to select a unique identification for each
preamplifier in a system. The ID number also assigns channel numbers to the
preamplifier. For instance, ID 1 includes channels 1-8, ID 2 includes channels 9-16
and so on to ID 8 which includes channels 57-64. Pushing the DATA knob once
allows the ID number field to changed by rotating the DATA knob. Pushing the DATA

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