Genz-Benz shen 150lt ユーザーガイド

 – The Shenandoah™ Acoustic 150LT. contains the most comprehensive direct output sec-

tion available on any acoustic instrument amplifier. Both XLR balanced and ¼” unbalanced outputs make “real world 

sense” when connecting with other equipment. The ¼” unbalanced outputs are true professional line level (+4 dBv) 

with an output impedance of 1k ohm, and can drive virtually any line level input, including power amplifiers. The XLR 

balanced output is “hot” mic level, rated at –30 dBv. This configuration allows the Shenandoah™ Acoustic 150LT to 

drive very long cable lengths (250+ feet) without problems or added noise. The XLR balanced direct outputs can be 

“ground lifted” with the global ground lift switch. This switch lifts pin 1 on all of the XLR balanced outputs to break 

ground any loops between the Shenandoah™ Acoustic 150LT and a PA system. Separate Channel 1 and Channel 2 

outputs are post channel volume/pre effects (to take advantage of the dual inputs on each channel) while the 

Channel 1+2 output is post master volume/post eq/post effects to aid in sending a “finished” mixed signal to a PA 

system or external power amplifier.

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 – The Shenandoah™ 150LT offers a 3 band (with sweepable mid) active 

equalizer for each channel. This equalizer, similar to those found on professional sound consoles, are very useful 

tools when used correctly. 

The corner frequency of the low frequency section is 125 Hz, shelving curve. This frequency is  particularly handy 

when dealing with low frequency feedback from a big dreadnaught guitar. A combination of volume reduction and 

turning down the low frequency control will generally get good results. Become familiar with the action of the controls 

since their effective gain range is quite large. The low frequency control is also handy for adding some “bottom” to a 

baritone sax and “chunk” to a mandolin or mando-cello. 

The corner frequency of the high frequency section is 8 kHz, shelving curve. 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 flutes cut through other players in loud club situations. 

The “sweepable mid” section features 12 dB of cut or boost with a bandwidth approximately 1 octave wide. The center 

frequency of this filter is continuously user adjustable from 250 Hz to 5 kHz with a single control. This filter is 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 find out just how quick it can be.  You will hear a clear and obvious accentuation of 

the ugliness you want to remove. 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 find need to use the mid section in “boost” mode, particularly 

common when adding higher mids (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.

It may be helpful to know  - The 9 O’Clock position is 350Hz, the 12 O’Clock position is 1KHz and the 3 O’Clock 
position is 2.5KHz.

 – The master volume control adjusts the overall volume of channel 1, channel 2 and the 

effects return (either on-board or digital). Typically, best results are obtained when this control is operated between the 

9:00 o’clock and 3:00 o’clock positions.