Presonus Audio electronic Single-Channel Tube Mid, Frequencies from 900Hz to 5kHz. The outer ring

				CONTROLS & OPERATION 2
				Mid
	S	0	M	The dual concentric potentiometer labeled MID controls
		2k
			O
	S		R
L	E		E	the frequencies from 900Hz to 5kHz. The outer ring
				provides boost or cut at the frequency selected by the
				inner knob by plus or minus twelve decibels with the
		-12900	5k+12	straight-up noon position equal to zero or no boost or
				cut. The inner control knob begins at 900Hz in the left

or fully counter-clockwise position and continues to 5kHz in the right or fully clockwise position. This control behaves in the same manner as the LOW control with the frequency widths delineated by the knob’s markings becoming wider as the knob travels to the right or the clockwise direction.

				High
	S	0	O	The Equalizer dual concentric control labeled HIGH
		5k
	S		M
			R
L	E		E	operates in the same manner as the LOW and MID
				controller. The inner HIGH control knob is used to
				boost or cut frequencies ranging from 3kHz to 15kHz
	-123k		15k+12	by as much as 12dB by adjusting the outer ring of the
				controller.

80Hz Switch

The DigiTUBE equalizer section contains a switch labeled 80Hz. Engaging this switch activates an 80Hz filter (often referred to as a rumble filter). This filter is useful for eliminating extraneous low-end sounds from the signal being ampli- fied. Frequencies from 80Hz and below are cut from the incoming signal. This will eliminate low-frequency noises such as air-conditioning hum or the sounds of nearby traffic or other vibrations that may be transmitted through the micro- phone stand into the microphone. It can also be useful for reducing the effect of electrical hum that may be the result of grounding problems.

EQ In

The EQ IN switch provides the ability to audition the effect that the equalizer is having on the signal being processed. Pushing the switch to the latched position inserts the equalizer into the signal path. Releasing the switch takes the EQ out of the signal path. You can quickly judge the effect your efforts at adjusting the equalization of the incoming signal are achieving and rapidly compare it to the un-equalized signal.

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