523 Parashelving EQ

523 Parashelving eQ
Intuitive tweaking for smooth, musical results.

The 523 Parashelving eQ is a unity-gain, dual-band fully parametric equalizer designed for everything from broad tonal shaping to precise frequency correction.

Each band offers continuously adjustable bandwidth, ranging from two octaves for wide and natural tonal changes to a narrow quarter octave for accurately targeting specific frequencies.

M.S.R.P.

$799.00

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Both parametric bands can also be switched to shelving mode for smoother tonal shaping. Unlike many equalizer designs, the 523 retains the selected frequency and gain settings when switching between parametric and shelving modes.

This makes it easy to compare both curves quickly and transparently without having to readjust the controls.

A proprietary Quagliardi permalloy-core input transformer provides generous headroom while maintaining exceptionally low levels of unwanted harmonic distortion.

When equalization alone is not enough, the selectable BLUE circuit introduces controlled second-harmonic distortion, adding depth, density, and character to the signal.

A relay-based true bypass completely removes the 523 from the signal path when disengaged.

Technical Specifications

Connections
Rear-panel input and output connections

System Gain
Unity gain, 0 dB, with both EQ bands disengaged

Center Frequency
Low-frequency band: 20 Hz to 700 Hz
High-frequency band: 500 Hz to 20 kHz

Bandwidth
Continuously adjustable from ¼ octave to 2 octaves

Band Gain
Maximum boost: +10 dB at minimum bandwidth
Maximum boost: +30 dB at maximum bandwidth

Input Impedance
1.5 kΩ with a 150 Ω source impedance
Hi-Z input: 1 MΩ

Output Impedance
Less than 70 Ω

Frequency Response
+0.45 dB at 20 Hz / −1.3 dB at 20 kHz

Total Harmonic Distortion (THD)
0.003% at +4 dBu output, unweighted
0.015% at +26 dBu output, unweighted

Equivalent Input Noise (EIN)
−130 dBu with a 160 Ω input load, unweighted

Power Requirements
±16 V DC, 100 mA

Dimensions
230 × 200 × 50 mm
9.0 × 7.8 × 2.0 in

Weight
0.410 kg
0.90 lb

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