Bose T1 ToneMatch, Руководство по обслуживанию

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Normal Channel Processing
Each input channel is fed through a dynamic processor into a three band equalizer and another
parametric EQ section. Then the signal is filtered with a Bose
® preset or ToneMatch ® filter and
volume/mute is applied. These post-fade signals are routed into three independent effects
processor (Reverb, Modulator, and Delay). The master output signal is formed by the sum of the
post-fade channel signal and the effects processors.
Aux
The aux section is formed by a multiplexer that taps the each channel signal at three different
spots. These are
a) Directly after the input (traditional “pre fade”)
b) After the dynamics processor and the EQ section
c) After the volume/mute control (traditional “post fade”)
The chosen signals are scaled and then summed into the Aux output signal
Master section
The output of the master summer is fed through the master volume control to the digital output
to the L1 Model II powered speaker system. The source analog master output can be selected
to be pre or post the master volume control. The output of the aux summer is send directly to
the analog Aux output. All outputs have limiter/clipper to prevent hard clipping of the D/A con-
verters in cases where the system is internally overdriven.
Master Output
The master output comes from U21, is filtered by U16, then converted to a balanced signal by
U17 and fed out the Master Output jack.
Auxiliary Output
The auxiliary output comes from U21, is filtered by U16, then converted to a balanced signal by
U18 and fed out the Aux Output jack.
ToneMatch Output
The S/PDIF signal from the DSP contains digital audio to the Venice power stand, and can also
carry two-way communication for code updates.
The ethercon connector provides input and output for isolated S/PDIF – format digital signals.
Pins 1 and 2 are the signal inputs; they are fed through common-mode choke T2 for RF isola-
tion and T4 for electrical (DC) isolation. D17 clips the received signal, and it is passed through
a low pass filter (C39, C40, C47, R266, R149, and R150) to U24, which acts as a comparator
with hysteresis.
U24 is also used to square the transmit S/PDIF signal output, which is passed through trans-
formers T3 and T1 to pins 3 and 6 on the ethercon connector.
Received S/PDIF signals are passed directly to the DSP.
Theory of Operation