Eventide H3000

Thirteen pounds of 16-bit silicon that turned a mono pitch-shifter into a fully MIDI-programmable stereo studio workhorse.

Overview

The H3000 is a software-based digital signal processor in a 3.5-inch-tall, 19-inch-wide rack chassis. It weighs 13 lbs net, 18 lbs in the shipping carton. Eventide built it around electronically balanced stereo inputs and outputs and a sophisticated MIDI implementation. According to the service documentation, it runs full 16-bit resolution at a 44.1 kHz sampling rate. Frequency response is specified at 5 Hz to 20 kHz ±1 dB, and ±0.5 dB typical. Dynamic range is greater than 92 dB A-weighted. Distortion is 0.01 percent (0.007 percent typical) at 1 kHz, measured 1 dB below clipping in pitch-change mode with zero shift and all levels at 0 dB. Delay runs up to 1.5 seconds, and pitch variation covers one octave up and two octaves down. Eventide's own advertising billed the unit as a "reinvention" of the Harmonizer, and the copy leaned hard on the numbers: typical 5 Hz - 20 kHz ±0.5 dB response, >92 dB A-weighted signal-to-noise, and full 16-bit resolution at 44.1 kHz.

The headline claim was that this was the first stereo Harmonizer. It was not two independent pitch shifters bolted together, but fully deglitched, in-sync stereo pitch change, pitched at broadcast work. Eventide's marketing also made much of a Diatonic Pitch Change program that generates musically correct harmony lines at any interval. The user specifies the key, and a single input becomes the correct triad chord. Beyond pitch, the box carried dozens of factory programs covering reverb, multitap, Digiplex, and chorus effects, plus the program Eventide named Death Flange. Mix (February 1988, p.43) described the H3000 as a reinvention of the Harmonizer with full MIDI programmability, including complete performance MIDI control of all parameters, usable with most any MIDI-controlling sequencer.

MIDI control is complete, not token. It covers program change plus performance control of all parameters, usable with most any MIDI-controlling sequencer. The service manual describes the whole machine as a software-based digital audio signal processor whose effects range from simple time delay to pitch shifting, and it treats the MIDI section as part of the architecture, not an add-on.

Inputs, Outputs, and Installation

The audio path is stereo, true differential balanced on the input side and differential, transformerless on the output side. Input levels ship set for pro audio at +4 dBm. The unit can be reconfigured for -10 dBm nominal operation by removing the top cover and moving small jumper blocks from the +4 pins to the -10 pins. The manual treats that as a routine job, not a service-bench affair. Power draw is modest for a rack processor: 75 watts, with the supply available in 110-130 V or 200-240 V versions, AC 50/60 Hz. The chassis measures 3.5 inches high by 19 inches wide by 13.5 inches deep (8.9 × 48 × 34.3 cm).

The manual is blunt about heat. The H3000 will get very hot if the top and bottom vent slots are blocked by other gear or if it lives in a sealed road case. Overheating in that condition can crash the audio in time or lock up the front panel. That is not a design flaw so much as a warning about rack hygiene. The entire machine rides on two main address and data busses, and if any digital chip in the system fails, the whole thing can crash or at minimum turn the audio to noise and distortion. When a basic delay or non-shifted Harmonizer program produces output that bears no resemblance to the input, the manual's diagnosis is that the audio has "crashed" - random noise from bus contention, wrong timing, or no timing at all. The manual also notes that the character of that noise will change with different programs, which is at least a useful diagnostic tell.

Serviceability and Diagnostics

Eventide's service literature is candid about the repair side. Hardware modifications and software changes are not difficult, but troubleshooting the digital electronics can be tough. The recommended bench kit is modest: a 100 MHz dual-trace oscilloscope, an audio oscillator/analyzer test set (the Amber model 3501 or equivalent), and a 100 MHz frequency counter. The most useful tool, per the manual, is the diagnostic SELFTEST EPROM available from Eventide. It drops into an EFFECT ROM slot and automatically tests and logs errors for the digital circuitry. Loop the audio outputs back to the inputs and MIDI OUT to MIDI IN, and the unit will check its own audio specs over time and exercise its MIDI section. Additional routines target very specific hardware areas and pair with a scope for deeper fault-finding.

The manual is equally direct about confirming a problem before opening the case. With a device this complex, operator error, wiring mistakes, or faulty installation account for plenty of what gets reported as a breakdown. If the unit passes processed audio, displays correct information on the front panel, and responds to the buttons and knob, it is in most cases working properly. A working understanding of differentially balanced inputs and outputs eliminates most wiring mistakes. Heat and static electricity are called out as the usual killers of boards and chips, and repairs are meant to go to a qualified service person whenever possible.

Variants and Context

The H3000-B is documented separately as carrying an AutoTime Squeeze time compression/expansion interface, which lets any frequency-controllable variable-speed tape machine be driven by the unit to shorten or lengthen an audio source. The same documentation lists a Function Generator for sound effects such as siren, helicopter, windstorm, and thunderbolt, assignable sweeps for flanges and chorus, and autopanning, along with 90 factory programs, 50 user-storable presets, and full MIDI implementation. The SE variant shows up in a July 1990 lab-test column in EQ-Magazine (July 1990, p.75), which noted that current S models could be updated to SE performance via a $600 factory upgrade and referenced a true stereo sampling option.

Eventide's own advertising pitched the H3000 at almost half the price of the company's previous top-of-the-line mono Harmonizer. That claim is the manufacturer's, not an independent verdict, and should be read as marketing copy.

Market Value

┌──────────────────────────────────────────────────────────────────────────┐
│ EVENTIDE H3000                                                  Nov 2026 │
├──────────────────────────────────────────────────────────────────────────┤
│ High      $2,857                                  Latest          $2,400 │
│ Median    $2,358                                  Trend                — │
│ Low       $119                                    Volume           ~4/mo │
├──────────────────────────────────────────────────────────────────────────┤
│ $3,000 ┤                                                                 │
│        │         .                                       .               │
│        │   .                          .                                 .│
│ $1,757 ┤.                                                                │
│        │                                                                 │
│        │                                                                 │
│        │                                                                 │
│   $100 ┤                                                      .          │
│        ├─────────────────────────────────────────────────────────────────│
│    vol │█  █     █                    █                  █    █         █│
│        └─────────────────────────────────────────────────────────────────│
│         2026-06                      2026-07                      2026-08│
└──────────────────────────────────────────────────────────────────────────┘

eBay completed sales. Excludes accessories, parts, and non-working units. Hover points for details.

eBay Listings

Search Eventide H3000 on eBay

As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.