SHENANDOAH™ ACOUSTIC 85
OWNER’S MANUAL
(FRONT PANEL)
(REAR PANEL)
PRODUCT DESCRIPTION
– The
Shenandoah
Acoustic 85
is configured as a 2 channel – 4
input 85 acoustic instrument amplifier. Each channel is equipped with both a ¼” unbalanced line
input and an XLR balanced microphone input (with phantom power). The 2 inputs on each channel
are summed (mixed) together at a 1:1 ratio. Each channel then passes through independent 3 band
equalizers with sweep midrange frequency. Equalization centers were carefully selected for use with
acoustic instruments. Each channel also contains individual send controls to the on-board Alesis®
15 program digital effects circuit. The channel signals are then summed together, mixed with the
digital effects return and passed on to the internal 85 watt power amplifier. The back panel contains
3 direct balanced outputs with ground lift switch, 3 unbalanced line outputs, an effects loop, effects
cancel jack, and 2-1/4” speaker jacks.
INPUTS
– The Shenandoah™ Acoustic 85 is equipped with 2 types of input jacks. The ¼” input is
unbalanced and “line level” with a useable sensitivity from 100 mV to 1 volt. The input impedance is
150 k ohms. The ¼” input will also accept most active balanced line sources, automatically
unbalancing them by recognizing the tip portion of the balanced signal. Additionally, the precision
input scaling preamp contains a 50 Hz, 12 dB/octave high pass filter (more effective and less
intrusive than the more common 6 dB filters) and an “RFI” filter (radio frequency interference) to
eliminate unwanted noise. The XLR input jack is balanced and “microphone level”, with a useable
sensitivity from –60dBv to –30 dBv. It contains a precision full range differential microphone preamp
with phantom power. For use with higher level sources (such as the balanced line level output from a
keyboard), a balanced pad network will be necessary to use the balanced input. Phantom power is
13.6 volts, compatible with virtually all commonly used condenser microphones. Dynamic
microphones can be used with no ill effect.
COMBINING XLR & ¼” INPUTS
– A unique feature of the Shenandoah™ Acoustic 85 is the ability
to mix the XLR balanced and ¼” unbalanced inputs on each channel. In many situations, this
effectively makes the amplifier function as a 4 channel amplifier. The most effective way to use this
feature is to set the volume on the channel using the XLR microphone input and then adjusting the
level control on the instrument itself (assuming that it has one) to blend levels between the 2 inputs.
Equalization will be common to both inputs on the channel.
