The Boss PH-1 Phaser is a compact four-stage phaser, released in 1977 as part of the debut "traffic light" trio of Boss compact pedals alongside the OD-1 OverDrive and SP-11. Boss describes it as producing "a mild phaser sound with a full low-end response" on a simple two-knob interface2. It was made in Japan from 1977 to 1981 and is no longer in production3.
What it does
Like the first phaser effects generally, the PH-1's design traces back to the goal of emulating the swirling sounds of rotating speaker systems3. Its circuit uses JFET-based phase shifting, the same approach found in early classics like the MXR Phase 45 and Phase 905. TONEHOME's history of the pedal says it "allowed musicians to get some very unique phasing tones beyond anything that had come before it," and notes that quiet operation and reliability made it a very popular effect3.
Boss's own retrospective calls the circuit out directly:
"A genuine four-stage phaser, the PH-1 was notable for its clarity and depth"
Four stages means four phase-shifting stages in the signal path, which shapes how pronounced the sweeping effect is. The PH-1 sits at the gentler end: Boss characterizes its sound as mild, with the low end left intact rather than thinned out2.
PH-1 versus PH-1R and PH-2
The PH-1 was followed in Boss's range by the PH-2 Super Phaser and the PH-1R, which added a Resonance control. Guitar Pedal X's Stefan Karlsson, reviewing Boss's early pedals, was blunt about the difference6:
"I have always favoured the PH-1R and PH-2 over the PH-1 - that additional Resonance control makes a huge difference!"
Players who want more sweep intensity from a Boss phaser have that control in mind; the PH-1's two-knob layout keeps things simpler. Boss's current PH-3 Phase Shifter carries the phaser line forward in the modern compact range, and phasers as a type are covered on the Phaser Pedals page278.
The 2017 reissue
The PH-1 returned once, in the Compact Pedal 40th Anniversary Box Set announced in December 2017, a limited edition of one-time-only reissues of the original three Boss compact pedal models4. Guitar World's Paul Riario reported that the reissue versions included a PSA-compatible power supply section with a protection circuit and noise filter, a reinforced battery snap, and an LED showing effect on/off status4. The reissues were hand-built in Japan4.
The PH-1 has not been reissued since the 2017 box set, and the original was discontinued in 198134. Units on the used market are vintage pedals.
Videos
Boss Pedal Workbench
Gear Confessions
MSMWorkshop
Questions
Is the Boss PH-1 still made?
No. The PH-1 was made in Japan from 1977 to 1981 and is no longer in production, so surviving units are vintage pedals. Boss did bring the model back once, as a one-time-only reissue in the Compact Pedal 40th Anniversary Box Set announced in 2017, alongside reissues of the OD-1 and SP-1. That box set was a limited edition, so the PH-1 remains out of the current lineup.
Where was the Boss PH-1 made?
The original PH-1 was made in Japan between 1977 and 1981. The 2017 anniversary reissues were also hand-built in Japan, according to Guitar World's report on the box set.
What is the difference between the Boss PH-1 and PH-2?
The PH-2 Super Phaser added a Resonance control on top of the PH-1's simpler two-knob layout. Guitar Pedal X's Stefan Karlsson wrote that he always favoured the PH-1R and PH-2 over the PH-1, saying the additional Resonance control makes a huge difference. The PH-1's own character is milder, with a full low-end response.
Was the Boss PH-1 ever reissued?
Once. Boss reissued the PH-1 as part of the Compact Pedal 40th Anniversary Box Set, announced in December 2017, which gathered one-time-only reissues of the original three Boss compact pedal models. The reissue version added a PSA-compatible power supply section with a protection circuit and noise filter, a reinforced battery snap, and an LED showing effect on/off status.
What does a four-stage phaser mean?
A four-stage phaser uses four phase-shifting stages in its circuit, which sets how many notches the effect sweeps through and how deep the swirl sounds. Boss's own article calls the PH-1 a genuine four-stage phaser, notable for its clarity and depth. Early phaser designs, including the PH-1's JFET-based approach, were aimed at the swirling sound of rotating speaker systems.
Sources (8)
- The PX-1 Plugout FX: Timeless BOSS Pedals Reborn, BOSS (articles.boss.info), 2025-06-06
- BOSS - PX-1 | Plugout FX, BOSS (www.boss.info)
- TONEHOME, TONEHOME
- New and Cool: Boss Compact Pedal 40th Anniversary Box Set, Guitar World, 2017-12-04
- Guitar Phaser Pedal Types: JFET, Optical, OTA, and Others, Function f(x), 2022-03-18
- Guitar Pedal X, Guitar Pedal X, 2025-08-28
- BOSS - PX-1 | Plugout FX, BOSS (boss.info)
- BOSS - PX-1 | Plugout FX, BOSS (boss.info)
