Dolby Laboratories Multichannel Audio Tool DP570 - Manual (Page 52)

36 Dolby ® DP570 Multichannel Audio Tool User’s Manual
Using the DP570 Features
4.13 Using an External Shaft Encoder to Control Master Volume
The master volume function is available on DP570s that have the Cat. No. 548 Analog
Output Card installed. The
GPI/O port has three pins that allow control of master volume
remotely by using a shaft encoder. Table 4‐5 describes the interface.
Table 4‐6 describes the electrical characteristics.
4.14 Emulator Bypass
When you enable Emulator Bypass, the front‐panel Esc button is illuminated. In this
mode, the only settings that affect the output are the router settings. Monitoring options
are limited to program selection. If you are using the
Lt/Rt Input , that signal is sent, without
decoding, to the Left and Right emulator outputs. Bass management remains active.
4.15 Solo Input Mode
The DP570 provides a two‐channel analog input that can be routed to the analog outputs.
This input is called
Solo because the feature provides a way to route a standard signal from
a mixer (such as the mixer’s solo bus output) into the monitor chain. The feature can also
be useful as a general‐purpose analog bypass.
Solo Input mode bypasses the digital audio inputs, and only the solo inputs from the
Analog I/O connector on the back panel route to the Left and Right outputs. If the Mono
speaker output is selected, the input signals are summed and fed to the Mono output.
The Solo input is available only by driving the Solo Control line on the GPI/O port. The Solo
Control line (pin 6) is level‐triggered and is active in the high state. The status of the Solo
input displays on the front‐panel Solo LED and is indicated on the Solo Tally line (pin 5)
on the GPI/O port.
4.16 Unity Gain Mode
Unity Gain mode defeats the audible effects of dialogue normalization while allowing the
dialnorm value to be used in choosing dynamic range control settings. It is valuable when
the emulator outputs of the DP570 are returned to the console for use as monitor inputs.
Table 4-5 Shaft Decoder Signal Descriptions
Signal Pin Description
Shaft 1 21 Shaft encoder input. Two square waves in a quadrature phase relationship:
Shaft 0 leads Shaft 1 by 90°: volume increases.
Shaft 0 lags Shaft 1 by 90°: volume decreases.
Shaft 0 20
Shaft Present 22 Ground this pin to activate control via shaft encoder. Pulled high internally
(10 k to +5 V).
Table 4-6 Shaft Decoder Signal Electrical Characteristics
Characteristic Min Max
VT+ Positive‐going input threshold voltage 1.2 V 2.1 V
VT– Negative‐going input threshold voltage 0.5 V 1.4 V
VH Hysteresis voltage 0.4 V 1.5 V