You have 2 different voices which you can select what steps you want them to create harmonies in (up to an octave up or down on each voice). You can also select the key that you are playing in, and it creates an instant harmony with your playing. Separate controls for each voice (level control and pitch control). The HR-2 does 1 and 2 part harmonies in any interval in the following keys…Am, Bm, Cm, Dm, Em, Fm, Gm, A, B, C, D, G, F. The HR-2 was discontinued 1998, but the Harmonist effect lives on in the new PS-5. The HR-2 was originally priced at $239.

Controls

  • Effect level knobs for A/B: These knobs are used to independently adjust the volumes of parts A and B. If either of the knobs are turned completely off, then you only have a 1-part harmony instead of a 2-part harmony.
  • Voice switches A/B: These knobs adjust the harmonic interval of voices A and B. You can select any of the following setting for each voice, A or B, independently: -1 octave, -6th, -5th, -4th, -3rd, detune, +3rd, +4th, +5th, +6th or +1 octave.
  • Key switch This knob allows you to select the key that corresponds to the song being played. The HR-2 then creates 1-part or 2-part harmony parts automatically.

Boss Advertisement text (1994):

BOSS is pleased to introduce the very first intelligent pitch-shifter pedal: the HR-2 Harmonist. The HR-2 can add one or two voices of harmony. The key can be selected and the interval and volume of each harmony can be independently adjusted. Features: Intelligent pitch-shifting; one or two voices of harmony Independently adjustable interval and volume 16-bit A/D/A conversion with 32kHz sampling rate.

BOSS HR-2 Harmonist

Boss Guitar Effects Guide Book vol.11 (1995):

The world’s first intelligent pitch shifter in a compact pedal, the HR-2 lets you select any suitable key from 12 Key Modes like major and minor in each semitone. This instantly adds correct 2-voice harmony to a guitar phrase. A new high-speed detection circuit ensures lightning fast response to speed picking passages. A Detector In jack allows correct pitch detection when combined with other effects.

Using the HR-2

  • For a twin lead sound: To sound just like two guitarists playing the same phrase, set only Voice A to +3. (Fig. 1: E.Level A 10, E.Level B 0, Voice A -3, Voice B -, Key -)
  • Guitar orchestration: Try setting Voice A to +4 and Voice B to +3 to create very impressive guitar orchestration by layering a two-voice harmony on top of the original guitar signal. (Fig. 2: E.Level A 8, E.Level B 8, Voice A -4, Voice B +3, Key -)
  • Detune sound: With both Voice A and Voice B set to Detune, the direct sound is overlapped with slightly pitch-shifted sound for a thick, chorus effect. (Fig. 1: E.Level A 5, E.Level B 5, Voice A DT, Voice B DT, Key -)

Specifications

  • Controls: E. Level, Voice A switch, Voice B switch, 12-way Key Switch
  • Connectors: Input, Detector In, Output A, Output B, AC Adaptor
  • Current Draw: 75 mA (DC 9V)
  • Recommended AC Adaptor: PSA Series

Labels

  • Pink – Made In Taiwan
  • Dark Gray – Made In Taiwan

The HR-2 was sold from December 1994 to January 1999.