Electronic Audio Experiments Surveyor V2.5

The Electronic Audio Experiments Surveyor is a compact re-interpretation of the Instrument Voicing Preamp (aka IVP), a cult classic and long discontinued rackmount preamplifier. The IVP is best known for its distinctively clangy tone and harsh attack at high treble settings—especially in conjunction with an aluminum neck guitar, single coil pickups, and full range speakers—but its unique solid-state voice transcends genre labels.

The Surveyor features a unique, transformer-loaded “Tube Voice” distortion generator that is highly responsive to the frequency content of the input signal. This is achieved by placing a two-band shelving EQ before distortion is applied—the complete opposite of most drive pedals. Using this method, gain may be selectively applied to a specific frequency band: boost the treble for that signature clang, or maximize the bass for fuzz overload. This variety of saturated textures isn’t just for guitar, either! The Surveyor is equally at home on bass, synthesizers, drum machines, even vocals.

CONTROLS

• Level: overall volume, with more than enough range for line level output or to overdrive the next thing in your signal path

• Gain: amount of overdrive/saturation equally applied to all frequencies; highly interactive with the Bass and Treble settings

• Bass: pre-clipping low shelf boost/cut, +/-12dB @ 100Hz

• Treble: pre-clipping high shelf boost/cut, +/-12dB @ 3KHz

• Hi/Lo (switch): sets the range of the gain control, +0dB in the Lo position and +14dB in the Hi position

SPECIFICATIONS

Size/Weight:121mm x 66mm x 40mm, 0.4kg

Bypass:Relay switching with true bypass

Input impedance @ 1 Khz: 1MΩ

Output impedance @ 1 Khz: <1kΩ

Power: 9V DC, 2.1 mm center negative barrel. The current draw is 70 mA.

We recommend a regulated, isolated power supply rated for 100 mA minimum. The PSU input is protected against reverse polarity and over-voltage up to 24V. Our pedals do not accept batteries.

CHANGELOG

• V2.5 (Spring 2024)
  - Minor electrical adjustments
  - Simplified bypass circuitry to remove microcontroller
  - Minor artwork/print adjustments

• V2-V2.4 (2021-2022, incremental changes)
  - New mechanical format (changed enclosure shape, knob spacing, jacks, etc)
  - Added power supply over-voltage shutdown circuit and ESD protection
  - Added Hi/Lo toggle to increase gain range

• V1
  - Original release