Kurzweil K2700 Musician's Manual page 362

Audio Interface
AUDIO INTERFACE Section
Hi-Z On Button
Use the Hi-Z On button to enable or disable Hi-Z. The Hi-Z On button is shorter when
Hi-Z is enabled, and taller when disabled.
When plugging an electric guitar, electric bass, or high-impedance microphone (crystal type)
directly into the AUDIO IN LEFT/RIGHT jacks using a cable with a 1/4" plug, press the
Hi-Z On button to enable Hi-Z.
When Hi-Z is enabled, both AUDIO IN LEFT/RIGHT jacks are configured to receive an
unbalanced high-impedance signal. Additional gain is applied to the signal, which is useful
for boosting low instrument signals.
When plugging a line level signal or self-powered internal preamp type microphone into the
jacks, Hi-Z should be disabled.
+48V On Button (Phantom Power On/Off)
Use the +48V On button to enable or disable 48-volt phantom power. When phantom
power is enabled, the LED next to the +48V On button is lit.
When plugging a microphone which requires phantom power into the AUDIO IN LEFT/
RIGHT XLR jacks, phantom power should be enabled.
When plugging a microphone into the AUDIO IN LEFT/RIGHT 1/4" jacks, phantom
power should be disabled.
Signal Level LEDs
The LEDs next to the INPUT 1 GAIN and INPUT 2 GAIN knobs provide a visual
indication of the signal level received by the rear panel AUDIO IN LEFT/RIGHT jacks
(signal level after being adjusted by the INPUT 1 GAIN and INPUT 2 GAIN knobs, and
Hi-Z On button).
Each signal level LED turns green when a significant input signal is present, or red when the
signal level is becoming excessive and risks being distorted. If an LED is steadily turning red,
the GAIN knob should be turned down to prevent the signal from distorting.
The signal level LEDs respond to audio waveform peaks, unlike analog "VU meters" which
respond to the short-term average. An ideal signal level will show green most of the time, and
red only very rarely during the loudest part of the performance.
LED Off: Signal is less than 5% (-20VU) of the maximum undistorted level (+6VU).
LED Green: Signal is between 5% (-20VU) and 50% (0VU) of maximum.
LED Red: Signal is more than 50% (0VU) of maximum.
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