The AD2077 mastering equalizer is an ultraistic design optimizing absolute signal integrity. Design features include 100% discrete pure class A signal amplifiers, state-of-the-art passive and active filter topologies and a DC coupled minimalist signal path. These unique designs offer the professional mastering engineer alternate tone selections in both filter domains while delivering the highest resolution and wide dynamic range with very low noise. Custom gold rotary switches give accuracy in 0.5dB, 1dB and 2dB steps. 104 switched frequencies per channel with X I0 range selectors provide frequency selections from 12Hz to 25kHz at 1/4 octave intervals. The Avalon AD2077 mastering equalizer is the most musically transparent analog EQ available today!

AD2077 EQUALIZER FEATURES
Pure Class A, 100% discrete design
Smooth musical detail and sonic excellence
Minimum audio signal path
Dual mono, fully switched controls
Transparent active and passive filter design
Very low noise -94dB
High headroom +30dB
Fully balanced inputs and outputs
DC coupled, no transformers in audio path
104 switched frequencies per channel
Mid bands use X10 frequency for extended range
Wide bandwidth -3dB 1Hz to 450kHz
Low distortion less than 0.5% THD and IMD
Switched range control 0.5dB, 1dB and 2dB steps
All signal routing with sealed silver relays
100% discrete power supplies for audio path
External 150W toroidal power supply

SONIC EXCELLENCE
The Avalon AD2077 Pure Class A mastering equalizer is the most advanced, low noise, fully switched parametric equalizer available today. Designed for absolute signal integrity and musical performance, the AD2077 combines the best active and passive filter topologies for sonic excellence unequaled by lesser designs. The AD2077 is the perfect solution for two buss music-program equalization and ultra-high performance analog mastering applications. Features include state-of-the-art, balanced 100% discrete, Pure Class A signal amplifiers, practical user features and rugged hardware designed to deliver true high performance audio for many years.

PASSIVE-ACTIVE FILTER DESIGN
Avalon equalizers feature the unique combination of both active and passive EQ filters. This special combination enables the AD2077 to deliver high speed transient detail at the operational extremes of real-world equalization demands. The passive high and low bands offer alternate musical tone range to the full function active parametric mid bands. Passive equalizers have long been a favorite with music lovers around the world . . . full bodied, powerful (up to +/-20dB, 40dB range !) and sweet frequency selections are the benefits of the passive high-low EQ bands. The full bandwidth twin mid bands provide switched frequency selection (X10 frequency multipliers for very wide range), switched Q (width) and amplitude control.

MINIMUM SIGNAL PATH DESIGN
Avalon's true symmetry design offers high-voltage, large headroom, extended bandwidth and very low noise. The use of 100% discrete, Pure Class A signal amplifiers give the serious mastering engineer unlimited sonic character and a natural harmonic detail that enhances the program material and becomes one with
the music itself.

AD2077 SPECIFICATIONS
Circuit Topology
High-voltage 100% discrete, balanced and symmetrical Class A Unity gain
Output Gain Range
Unity Gain
Maximum Input Level
+30dB balanced XLR pin 2 hot
Maximum Output Level
+32dB balanced 600 ohms, DC coupled, high-current discrete Class A
Input / Output Type
XLR type, pin 2 hot balanced
Noise 20kHz Unweighted
-94dB (EQ in)
Distortion THD, IMD
0.5% (typical 0.05% at +6dB 1kHz)
Frequency Response -3dB
1Hz to 450kHz (input band limited)
Equalizer Type
Passive high and low bands plus two fully parametric mid bands
Bypass
Hard-wire relay bypass for equalizer L-R in-out plus silent opto switch for seamless stereo bypass.
Low Band F1 Passive, switched amplitude to -20dB to +20dB in 0.5dB, 1dB or 2dB steps
F1 Frequency Range
shelf or peak-dip curve, switched 18, 25, 30, 50, 72, 100, 150, 200, 300, 400Hz
Mid Band F2
Active, switched amplitude to -10dB to +10dB in 0.5dB or 1dB steps
F2 Frequency Range
Switched 12, 15, 18, 21, 25, 30, 36, 42, 50, 60, 70, 84, 100,
120, 140, 170, 200, 240, 280, 340, 400Hz, (x10) 120, 150, 180, 210, 250, 300, 360, 420, 500, 600, 700, 840, 1k, 1k2, 1k4, 1k7, 2k, 2k4, 2k8, 3k4, 4kHz
Q (width) switched 5 positions 6, 9, 12, 15, 18dB per octave
Mid Band F3
Active, switched amplitude to -10dB to +10dB in 0.5dB or 1dB steps
F3 Frequency Range
Switched 140, 160, 180, 210, 250, 300, 350, 420, 500, 600, 700, 840, 1k, 1k2, 1k4, 1k5, 1k6, 1k8, 2k, 2k2, 2k4, (x10) 1k4, 1k6, 1k8, 2k1, 2k5, 3k, 3k5, 4k2, 5k, 6k, 7k, 8k4, 10k, 12k, 14k, 15k, 16k, 18k, 20k, 22k, 24kHz
Q (width) switched 5 positions 6, 9, 12, 15, 18dB per octave
High Band F4
Passive, switched amplitude to -20dB to +20dB in 0.5dB, 1dB or 2dB steps,
F4 Frequency Range
shelf or peak-dip curve, switched 3k, 4k, 6k, 8k, 10k, 12k, 15k, 17k, 20k, 25kHz
AC-DC Power
External AC supply, 150w toroidal transformer, 4 pin cable 90v ac isolated
(B2T Power Supply Included)
100-240v selectable 50/60Hz, 150w max
Dimensions
19 x 7 x 15 in (482 x 178 x 380mm)
Shipping weight
40lbs (13.6 kg)