Mic Pre / Inductor EQ

Selects between mic and line inputs.

Continuously variable +/-6 dB level trim control.

Sends the mic preamp signal directly to the EQ when engaged.

A 12-way precision rotary switch controls gain from 0 to 66 dB in 6 dB steps.

Pushing the Silk button cycles the Silk modes from Red to Blue to OFF. Silk reduces the negative feedback on the output transformer, adding harmonic content as the texture is increased. Red Silk accentuates the musical harmonic saturation from the mid and high frequencies, while Blue Silk accentuates harmonics from the low and low-mid frequencies. By manipulating the Texture control, the amount of Silk can be changed from essentially absent, to roughly 4-5% THD (mostly second order) depending on how hard the output transformer is being driven.

The high pass filter is continuously variable from 20-250Hz and engaged by the HPF switch, which illuminates when engaged. It is a valuable aid in any signal chain, but particularly so in a microphone preamplifier. Signals below the selected frequency are attenuated at a rate of 12db / octave, getting rid of proximity effect, building rumble, air handling, motor hum, etc.

12dB/octave High Pass Filter, variable from 20 - 250 Hz.

+/- 15dB, Shelf or Peak, selectable at 8 kHz to 16 kHz.

+/- 15dB with 6 center frequencies; 200 Hz, 350 Hz, 700 Hz, 1.5 kHz, 3 kHz and 6 kHz, with MID HI Q switch to narrow the bandwidth or increase the Q of the filter.

+/- 15dB, Shelf or Peak, selectable at 35 Hz, 60 Hz, 100 Hz or 220 Hz.

Engages phantom power on the microphone input

Push button inverts the polarity of the signal path, and illuminates when engaged. The symbol “Ø” is often used to denote opposite polarity.

An eight-segment LED bar-graph meter displays output level (pre-Silk). The color range proceeds from green for lower level signals, yellow for intermediate signals, and red for high levels. When the 5052 is clipped, the highest red LED will hold longer depending on how far above the clip threshold the signal was.

Un-weighted, 22 Hz - 22 kHz, source impedance 150 Ohm balanced.

Mic Pre Out @ unity gain: Better than -102 dBV

Main Out @ unity gain: Better than -103 dBV

With gain @ +66 dB: Better than -60 dBV

Equivalent Input Noise: Better than -126 dB

Gain Unity: up to +66 dB in 6 dB steps followed by a +/- 6 dB trim

Gain +/- 6 dB continuously adjustable

Un-weighted, 22 Hz - 22 kHz, source impedance 40 Ohm balanced.

No load: Via line input with 40 Ohm source impedance

Better than -102 dBV

+/- 0.1 dBu from 10 Hz to 31.5 kHz

-2.6 dB @ 120 kHz

25 dBu

@ 1 kHz, +20 dBu output level, no load: Better than 0.002%

@ 20 Hz, +20 dBu output level, no load: 0.25% Typical (2nd and 3rd harmonic)

Measured via line input.

Un-weighted, 22Hz - 22kHz, source impedance 40 Ohm balanced. 

No load: Better than -102 dBV

+/- 0.1 dBu from 10 Hz to 40 kHz

-1 dB @ 174 kHz

25 dBu

@ 1 kHz, +20 dBu output level, no load: Better than 0.002%

@ 20 Hz, +20 dBu output level, no load: 0.08% Typical (2nd and 3rd harmonic)

TEXTURE @ min.

@ 100 Hz, +20 dBu input level, no load 0.015%, mostly 3rd harmonic (typical)

TEXTURE @ max.

@ 100 Hz, +20 dBu input level, no load 1.5%, mostly 2rd harmonic (typical)

TEXTURE @ min.

@ 100 Hz, +20 dBu input level, no load 0.0075%, mostly 3rd harmonic (typical)

TEXTURE @ max.

@ 100 Hz, +20 dBu input level, no load 1%, mostly 2rd harmonic (typical)

Un-weighted, 22 Hz - 22 kHz, source impedance 40 Ohm balanced.

No Load: Noise Better than -105 dBV

+/- 0.1 dBu from 10 Hz to 40 kHz

-1 dB @ 174 kHz

26 dBu

@ 1 kHz, +20 dBu output level, hi Z: Better than 0.002%

@ 20 Hz, +20 dBu output level, hi Z: 0.006% Typical (2nd and 3rd harmonic)

Continuously variable swept frequency from 20 Hz to 250 Hz.

Slope: 12 dB/Octave

Un-weighted, 22 Hz-22 kHz, source impedance 40 Ohm balanced.

No load: Better than -95 dBV

25 dBu

Supplied by internal switching converter, switch selectable on front faceplate

From 20 Hz to 20 kHz, +25 dBu

@ +/-24VDC maximum current draw: 0.26A/0.20A