Avalon Design

Avalon AD2055 Dual Mono, Pure Class A Parametric Music Equalizer

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  • Regular price R 88,594.16


Avalon AD2055 Dual Mono, Pure Class A Parametric Music Equalizer

The AD2055 combines 100% discrete, pure class A signal amplifiers with state-of- the-art passive and active filter topologies. The AD2055's unique circuitry delivers very high resolution transient detail at the operational extremes of real world equalization demands. The AD2055 auto-bias DC servo loop control eliminates the need for all interstage capacitor coupling. The AD2055 breathes life into all musical performances!


The Avalon AD2055 Pure Class A music equalizer is the most powerful, low noise parametric equalizer available today. Designed to optimize absolute signal integrity and musical performance, the AD2055 combines the best of active and passive filter topologies with sonic excellence unequaled by lesser designs. The AD2055 is the perfect solution for two buss music-program equalization, special instrument EQ and FX applications and ultra high performance mastering studio's.

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. 


Avalon equalizers feature the unique combination of both active and passive filter EQ designs. This special combination enables the AD2055 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 +/-32dB, 64dB range !) and sweet frequency selections are the benefits of the passive high-low EQ bands. The full bandwidth twin mid bands provide variable frequency selection (X10 frequency multipliers for very wide range), variable Q (width) and amplitude control. 


Avalon's advanced 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 music professional unlimited sonic character and a natural harmonic detail that enhances the program material and becomes one with the music itself. The Avalon AD2055 breathes life!


Circuit Topology

High-voltage 100% discrete, balanced and symmetrical Class A

Output Gain Range

Unity Gain

Maximum Input Level

+30dB balanced XLR pin 2 hot

Maximum OutputLevel

+32dB balanced 600 ohms, DC coupled, high-current discrete Class A

Input / Output Type

XLR type, pin 2 hot balanced

Noise 20kHzUnweighted

-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


Hard-wire relay bypass for equalizer in-out

Low Band F1

Passive, amplitude to -32dB to +32dB shelf or peak-dip curve

F1 Frequency Range

Switched 10 position 18Hz, 25, 30, 50, 72, 100, 150, 215, 300, 450Hz

Mid Band F2

Active, amplitude to -16dB to +16dB peak-dip curve

F2 Frequency Range

Variable 35Hz to 450Hz (x10) 350Hz to 4k5Hz, Q (width) 0.3 to 3.0

Mid Band F3

Active, amplitude to -16dB to +16dB peak-dip curve

F3 Frequency Range

Variable 160Hz to 2k0Hz (x10) 1k6Hz to 20kHz, Q (width) 0.3 to 3.0

High Band F4

Passive, amplitude to -26dB to +26dB shelf or peak-dip curve

F4 Frequency Range

Switched 10 position 1k5Hz, 2k5, 3k5, 5k, 7k2, 10k, 12k5, 15k, 20k, 25kHz

AC-DC Power

External AC supply, 150w toroidal transformer, 4 pin cable 90v isolated,

(B2T Power Supply Included)

100-240v selectable 50/60Hz, 150w max


19 x 3.5 x 12 in (482 x 88 x 305mm)

Shipping weight

30lbs (13.6 kg)