Ashly P70 Owners Manual
Ashly P70 Owners Manual
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out-of-phase. The channel 1 output terminal is used as the positive and the
channel 2 output terminal becomes the negative. The COMMON terminals are not
used.
CAUTION! NEVER GROUND EITHER OUTPUT TERMINAL.
In bridging mode, the output voltage is doubled from 70V to 140V.
ONLY
USE 140V STEP-DOWN TRANSFORMERS WHEN RUNNING IN BRIDGED
MONO
. If you attempt to use a 70V transformer in this mode, you will have twice
the rated current through the 70V transformer, creating a potential fire hazard. You
will also saturate the core of the transformer, adding distortion to the signal. The
amplifier will become loaded down below the desired point and run hotter than
normal, increasing the likelihood of thermal shut-down.
INPUT OPTIONS
Input option panels are available to provide built-in features such as stereo
limiting, mic and line inputs, crossover for bi-amplified systems, and input
transformers for signal isolation. Ashly P70 series amplifiers as well as all other
Ashly amps (excluding the single rack space SRA-120) will accept Ashly input
options. A brief description of currently stocked input options follows. Consult
your dealer for detailed information on the input options, or call the factory.
TRANSFORMER INPUT OPTION
The ITC-2 transformer input option may be installed in either or both
amplifier channels. The input transformer provides complete electrical isolation
from the amplifier and its signal source to eliminate any ground-induced hum noise,
as well as further reducing any common-mode noise and radio frequency interfer-
ence. The ITC-2 must be installed in the standard input panel and does not change
the operation of any switches or controls.
LIMITER INPUT OPTION
The CL-2 limiter input option provides peak signal limiting from excessive
input levels for speaker protection and overall level control. Separate recessed
limiter threshold controls, limit indicator LED’s and limit on/off switches are
provided on each channel allowing fully discrete stereo limiting operation.
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MONO OPERATION
Figure 5: Operation in Normal Mono Mode
With the MONO switch depressed, the channel 1 input is routed to both
amplifier channels. Both channels are then controlled by the channel 1 level
control. Both outputs will be identical and can be connected to separate speaker
lines. If you wish to drive both channels of the amp with one signal and yet maintain
seperate level control, simply run the amp in stereo mode and hardwire channel one
input to channel two input on the terminal strip.
CAUTION! NEVER CONNECT
THE OUTPUT TERMINALS TOGETHER!
BRIDGING OPERATION (140 Volt)
Figure 6: Operation in Bridging Mode
To operate in bridging mode, depress both the MONO switch and the BRIDGING
switch . The MONO switch depressed routes the channel 1 input to both amplifier
channels and the BRIDGING switch depressed inverts the phase of the input signal
before it is fed to the channel 2 power amp section. The two amplifiers’ outputs are
therefore 180 degrees
