Aurorasound EQ-100 Phono Preamp Equalizer Adaptive Multi-curve

Aurorasound EQ-100 Phono Equalizer

The Aurorasound EQ-100 is a state-of-the-art phono equalizer preamplifier designed for vinyl enthusiasts and collectors of analogue and vintage records. Built as an adaptive multi-curve phono stage, it allows precise optimisation of playback for a wide range of historical recording standards.

Key features:

• monaural phono equalizer (two units required for stereo)
• compatible with SP (78rpm) and monaural LP (33⅓rpm) records
• 10 turnover (low frequency) settings
• 10 roll-off (high frequency) settings
• 100 possible EQ curve combinations
• preset EQ curves: RIAA, AES, DECCA, Columbia, NAB
• dedicated 78rpm EQ presets (US and European variations)
• built-in bass limiter for DECCA, Columbia, and RIAA
• MC and MM cartridge compatibility
• optimised load settings for modern MC and variable reluctance cartridges
• dual inputs and dual outputs
• standard 2Vrms output level
• large front-panel mute button
• instant EQ comparison switching (Variable/RIAA)
• wooden case with fold-away tilting stands

Design and performance:

The EQ-100 is designed to accurately reproduce a wide range of historical recording curves, making it ideal for collectors of pre-RIAA vinyl and shellac records. Independent control of turnover and roll-off allows precise tuning without interaction between settings, giving a high level of flexibility.

Preset curves simplify setup for common standards, while fine adjustment enables more exact matching to specific pressings. The inclusion of dedicated bass limiters for certain labels ensures controlled low-frequency response and more accurate playback.

When using a stereo cartridge, the internal circuit cancels vertical signal components, extracting only the horizontal (R+L) signal. This reduces noise and improves clarity when playing mono records.

Materials and construction:

• precision resistor and capacitor switching via rotary controls
• Burr Brown OPA627 and Linear Technology LT1028 op-amps
• German WIMA and Japanese polypropylene capacitors
• TAKMAN resistors
• toroidal transformer power supply
• low-noise Schottky diodes
• high-quality switches from ALPS, OMRON, and NKK

The EQ-100 avoids the use of potentiometers for EQ adjustment, instead using fixed component switching for greater accuracy, repeatability, and long-term reliability.

Sound characteristics:

• highly accurate reproduction of vintage EQ curves
• low noise with excellent signal clarity
• controlled low-frequency response
• detailed and natural midrange presentation
• improved separation and reduced surface noise on mono records

Build and usability:

The EQ-100 is designed for both dedicated collectors and enthusiasts exploring vintage recordings. The large mute button allows silent cueing and record changes, particularly useful with older records that may produce noise at the end of playback.

The wooden chassis is styled to complement vintage equipment, while the fold-away tilting stands improve visibility and ease of use during operation.

Note:

The EQ-100 is a mono device. For stereo playback, two units are required to operate as independent left and right channel phono equalizers.