Loc phono preamp - user selectable components, Millennia – Millennia LOC Analog Legacy Phonographic / Archiving Preamplifier User Manual

Page 6

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10

LOC

Millennia

Media & Music Systems



LOC

Millennia

Media & Music Systems

(

8) BAND IN/OUT SWITCH "IN"

Pushbutton switch which places its associated EQ band in circuit or out of circuit. There are

eight bands of equalization on the LOC Analog Legacy. Four bands provide precise phono

compensation, including RIAA and an unlimited number of legacy curves. Four additional

bands (marked "FILTER") provide additional sculpting and repair tools. An EQ band is in-

circuit when its associated band switch is depressed and LED is illuminated. Band In/Out

switches are provided both for comparing a single EQ band setting versus flat-band re-

sponse, and for bypassing any band entirely, such as with flat acoustic recordings.

(9) FREQUENCY SELECT ROTARY SWITCH

Six position rotary switch (Grayhill, gold contacts, military spec) which selects fixed high and

low band frequency points. LF compensation frequencies are preset to 200, 250, 300, 400,

500/RIAA, and 700/USER (in Hz). HF compensation frequencies are preset at 10 kHz to -5.0,

-7.0, -9.5, -11.5, -13.7/RIAA, and -16.0/USER (in dB). Where a switch is marked "USER",

the user may change the value of a fixed capacitor to allow for virtually any compensation

frequencies not preset on the factory stock rotary switch points. See printed circuit board

diagram on page 12 for capacitor socket location (C14 on LF board and C8 on HF board).

The LOC compensation and filter circuits are based upon a unique shunt topology. This

topology is unlike conventional "state variable" filters in that only one signal path amplifier is

employed. Compare this with conventional filter designs employing upwards of four to seven

signal path amplifiers. Fewer amplifiers means greatly improved sonic integrity.

LF filter points are preset to 20, 35, 60, 100, 180, and 260 Hertz. High frequency filter points

are preset to 1, 2, 3, 5, 8, and 12 kHz.

(10) PEAK/SHELF SELECT SWITCH

Pushbutton switch which selects LF and HF filter curve shape. When switch is depressed

and LED is illuminated, EQ is shelving at 6 dB per octave. When switch is not depressed, EQ

is peaking with a fixed "Q" of 1.0 about the center frequency selected.

(11) BOOST/CUT CONTROL

Four conductive plastic rotary potentiometers (French Vishay) offering up to +10 dB of boost

and -10 dB of cut. Boost/Cut potentiometer has 21 detented positions for accurate repeatabil-

ity and session logging.

(12) POWER SWITCH "POWER"

Rocker switch for switching AC line power on and off.

LOC Phono Preamp - User Selectable Components

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