Operating Manual - MFA-8000 and MFA-6000 Power Amplifier
10
7.6
Speaker Outputs - Speakon Connectors
Neutrik Speakon connectors are provided to con-
nect with the Neutrik NL4FC 4-conductor plug. For the
channel 1 and 2 Speakon connectors, the following pin
assignment is used:
Pin 1+ = speaker hot
Pin 1- = speaker ground
The third Speakon connector in the center pro-
vides a stereo connection if operating in stereo mode or a
bridged connection if operating in bridged mode. The
pin assignment for this connector is:
Stereo Mode
Bridged Mode
Pin 1+ = Ch.1 hot
Speaker hot
Pin 1- = Ch.1 ground
Pin 2+ = Ch.2 hot
Speaker return
Pin 2- = Ch.2 ground
8.
INPUT OPTIONS
Input option panels are available to provide built-
in features such as a stereo compressor-limiter, a mic and
line mixer, a crossover for bi-amplified systems, and in-
put transformers for signal isolation. In addition to the
MFA amplifiers, all FTX MOS-FET amps, the CFT-1800
convection cooled amp, and P70 series 70 volt amps will
accept Ashly input option panels. A brief description of
currently stocked input options follows. Consult your
dealer for detailed information on input options, or call
the factory.
8.1
Input Isolation Transformer
The input isolation transformer can be installed
directly into the standard input supplied with every
ASHLY amplifier (except for the single rack space SRA-
120). The input transformer provides complete electrical
isolation from the amplifier and its signal source to elimi-
nate any ground-induced hum noise. The transformer in-
put also further reduces any common-mode noise and ra-
dio frequency interference. The transformer option is in-
stalled within the standard input panel and does not change
the operation of any switches or controls.
8.2
Peak Limiter/Compressor
The limiter input option provides peak signal lim-
iting from excessive input levels for speaker protection
and overall level control. Separate limiter threshold con-
trols, limit indicator LED’s and limit on/off switches are
provided on each channel allowing fully discrete stereo
limiting operation.
8.3
Two-Way Crossover
The crossover input option provides fixed-fre-
quency 24 dB/octave high-pass and low pass filters al-
lowing the two amplifier channels to operate bi-amped,
full range with low out, both channels low out, or bridged
low out. Auxiliary low and high outputs are available for
connecting additional amplifiers. Included with the cross-
over input option are single in-line package (SIP) resis-
tor networks which allow preselection between standard
crossover frequencies of 160Hz, 500Hz, 750Hz, 1.2KHz,
and 1.6KHz. 360
°
of phase control is provided for proper
acoustical alignment of high and low frequency drivers.
Selectable constant directivity horn EQ is provided for
both small and large horn designs.
8.4
Six Input Mic-Line Mixer
The mixer input option provides four high-im-
pedance line inputs and two balanced low-impedance mi-
crophone inputs, each with its own level control. A swit-
chable 200 Hz high-pass filter is provided on the mic in-
puts to reduce unwanted low frequency noise. An inter-
nal jumper allows selection of 15 Volt phantom power
applied to the mic inputs for use with condenser mics.
The option has a master level control and selectable ste-
reo, mono and bridging modes. Insert Points are avail-
able for patching external processing into the left and right
channels.
