BACK PANEL
SPEAKER OUTPUTS
- Three speaker outputs are provided that work in conjunction with the Mode switch for
fl exible power distribution to the speakers. With the Mode switch in the Mono Bridged position only the bridged
speaker jack is active. This jack delivers the full 200 watts of power from the amplifi er into a single 8 ohm load. This
is where the combo’s 8 ohm 12” speaker is plugged in from the factory. With the Mode switch in the Dual
position only, the Dual speaker jacks are active. It is possible to drive external speakers with the amp A output and
the internal speaker with the amp B output when using the Dual mode position. Driving speaker loads below the
rated minimum loads (8 ohms min. bridged mode; 4 ohms min. dual mode) will result in distortion and possibly
intermittent operation as the protection circuits are activated. We offer the Shen-200-EXT L/R speaker enclosures
that are a matched pair of Left and Right imaged extension speakers that offer a 10” woofer and compression
tweeter for use with either the Shenandoah™ Stereo Delux 200 or the Shenandoah™ Acoustic Pro.
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HIGH FREQUENCY EQ
- The corner frequency of the high frequency section is 8 kHz, shelving curve type and
provides cut or boost of 15 db. This frequency is especially useful for taming the bright harshness of some
mandolins, violins, brass and reeds. It can also be used to help acoustic guitars, cellos and fl utes cut through other
players in loud club situations, or where drums are present.
MIDRANGE EQ
- The “sweep mid” section features an independent midrange equalizer, peaking curve type, with
over 12 dB of cut or boost and a bandwidth approximately 1 octave wide. The center frequencies of these
equalization fi lters are continuously user adjustable from 250 Hz to 5kHz with the corresponding frequency control.
These fi lters are typically (but not always) used to reduce or remove offending frequencies in the instrument’s
pick-up response. Removing only the minimum amount necessary will yield the most acoustically rewarding results.
The easiest and most repeatable way to determine the offending frequency range is to boost the mid level
somewhat (but not to the point of feedback) and while playing, sweep the frequency control slowly across its range.
You may need a third hand until it becomes second nature, but soon you will fi nd out just how quick it can be. You
will hear a clear and obvious accentuation of the “ugliness” you wish to remove. Then, reduce the gain control until
the sound you desire is attained. The ear is a most sensitive and discriminating piece of test equipment when used
in this manner — another good reason to protect them! This is the way many touring sound engineers equalize,
since it is quick, accurate and repeatable. Occasionally, you will fi nd need to use the mid section in “boost” mode,
particularly common when adding higher midrange (bite) to an otherwise dull instrument, or adding low mid “body”
to an otherwise thin sound. Spend some time experimenting so that the process becomes creative as well as
corrective.
AUXILUARY INPUT LEVEL CONTROL
– The Shenandoah™ Acoustic Pro is equipped with both ¼” and dual RCA
aux. input jacks and aux. level control. These rear panel jacks are internally summed, and feed the stereo mix via
the aux. level control. Both aux. inputs are line level, for use with drum machines, CD, MP3 and tape players.
MASTER VOLUME
– The master volume control adjusts the overall volume of the mix of channel 1, channel 2, aux.
input and effects return. Typically, best results are obtained when this control is operated between the 9:00 and 3:00
positions.
MASTER STATUS LED INDICATORS
- Output status LED’s are provided to indicate Signal present and Clipping.
The green LED monitors the Pre-Master Volume output signal from the preamp before the power amp section. The
red LED indicates Clip/Limit and indicates that the maximum power threshold has been crossed and the internal
“soft-clip” limiter is active. Driving the amp 6db beyond this point will cause gradual clipping.
