• Brand: PreSonus
  • Product Code: Eureka
  • Availability: In Stock

The name “Eureka” derives from a Greek word meaning “I have found it!” It was made famous by the ancient Greek scholar Archimedes, indicating exultation at a great discovery. Try the sweet-sounding, super-versatile Eureka preamp and signal processor, and you’ll discover the answer to a variety of sonic needs.

One of our best-selling products, the Eureka is equally at home in the studio or at the gig. With separate mic, line, and instrument inputs, you can employ it on almost any sound source.

Sweetening starts with a high-headroom Class A solid-state mic preamplifier with +22 dBu of headroom, providing wide dynamic range and excellent transient-response characteristics.

↓ Read more about Class A designs.


The preamp’s variable mic-input impedance enables you to vary the “color” of your sound and get the best performance from any type of microphone.

↓ Read more about variable microphone-input impedance.


A Saturate control simulates the effects of tape saturation and tube warmth so you can go from crystal-clear to warm and rich.

↓ Read more about the Saturate control.


Go with the Flow

The Eureka’s versatility stems in part from its malleable signal flow. With both XLR and ¼” line outputs, you can connect the Eureka to almost any recording interface, amp, or P.A. system. The EQ can be pre- or post-compressor, and you can bypass each independently. Balanced send and return jacks enable you to insert your favorite outboard processor before the compressor and EQ.

The backlit VU meter can display gain reduction or output gain.

Compression, EQ, and More

The channel strip’s fast, fully variable compressor provides Attack, Release, and Ratio controls and can be switched between hard and soft knee.

↓ Read more about soft versus hard knee.


The compressor includes an internal sidechain with variable (10 Hz to 10 kHz) high-pass filter, so it can achieve anything from hard pumping to transparent compression.

↓ Read more about sidechains.


The Eureka’s three-band, fully parametric EQ has overlapping frequency selection on each band. It can be used pre- or post-compressor and can be bypassed.

↓ Read more about the EQ section.


Of course the Eureka provides all of the secondary features you need in a preamp/channel strip.  A 20 dB pad lets you tame hot input signals, and a high-pass filter attenuates all frequencies below 80 Hz by 12 dB. Polarity reverse enables you to deal with phase problems when using open mics.

Try the Eureka. Like the great Archimedes, you’ll be shouting, “I have found the solution!”



  • Input/Output
  • 1 unbalanced ¼” instrument input (front panel)
  • 1 balanced ¼” line input
  • 1 balanced XLR mic input
  • 1 balanced ¼” line output
  • 1 balanced XLR line output
  • 1 balanced ¼” insert send (output)
  • 1 balanced ¼” insert return (input)
  • Fast, fully variable compressor
  • Attack, Release, Ratio, Threshold, and (makeup) Gain
  • Soft/Hard Knee switch
  • Bypass switch
  • Internal sidechain with variable (10 Hz to 10 kHz) high-pass filter
  • 3-band parametric equalizer
  • Gain, Frequency, and Q controls
  • Switchable pre-/post-compressor
  • Bypass switch
  • Meters, Controls, and Features
  • Gain control with +52 dB of gain for the mic input and +44 dB of gain for the instrument input
  • 48V phantom power
  • 80 Hz high-pass filter
  • -20 dB pad
  • Polarity-reverse switch
  • Variable microphone input impedance (50, 150, 600, 1,500, 2,500 Hz)
  • Variable preamp Saturate control (simulates tape saturation and tube warmth)
  • Line-input select button
  • Input clip indicator (LED)
  • Master level control
  • Backlit VU meter
    • Meter Output Gain or Gain Reduction
  • Digitalia
  • 1 digital expansion-card slot for optional AD192 24-bit/192 kHz AES/EBU and S/PDIF digital output card (discontinued)
  • Physical
  • 1U 19” rack-mountable, rugged steel chassis
  • Sealed, detented, metal rotary controls
  • Internal power supply with standard IEC connector
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