The Subdecay Quasar Phase Modulator V.4 is an all-analog multi-mode phaser from Subdecay, the Oregon pedal maker. Where a conventional phaser gives you one sweep shape and a speed knob, the Quasar packs eleven modes into one pedal, covering everything from traditional phasing to envelope-driven sweeps, step sequencing and synchronized tremolo. Subdecay describes it as offering "pure analog tone with modern features" and a "wide range of traditional and experimental sounds"1.
Eleven modes in one phaser
The Quasar V.4 is the fourth version of Subdecay's multi-mode phase pedal line, a design the company has been building since 200512. The pedal's control surface is deliberately simple: a Mode knob that selects any of the eleven modes, plus Depth and Offset knobs. Depth controls modulation depth, while Offset is mode dependent. As Subdecay puts it, "The offset knob is mode dependent. It sets anything from the phaser sweep center point to synchronized modulation ratios"1.
The eleven modes break down into four families:
| Modes | Family | What it covers |
|---|---|---|
| 1 to 4 | Cross modulation (X-MOD) | Includes mode 4, "Synchronized phaser and tremolo"1 |
| 5 to 6 | Step Sequencing (STEP) | Sequenced modulation patterns1 |
| 7 to 8 | Envelope (ENV) | Envelope-driven phasing1 |
| 9 to 11 | Traditional | Conventional phaser modes1 |
What the Offset knob does changes with the mode you are in. In mode 8, Envelope Phaser, Offset controls the phaser's resting point. In mode 9, Rotary / Vibrato, it controls tremolo depth. In mode 10, Slow Triangle LFO, it controls the center point of modulation1. That single knob doing different jobs per mode is the core of the Quasar's design: a small control surface that reaches a wide range of sounds depending on where Mode is set.
The Quasar Phaser v4 is listed by Subdecay as out of production and sits in the discontinued category on its site1. The line has taken several forms over the years, including the Quasar DLX, the Quasar Quantum and the Quasar DLX Deluxe Phaser.
Where it came from
Subdecay's Quasar phaser has gone through several versions, and the V.4 was shown at NAMM 2018, where Delicious Audio's Paolo De Gregorio reported that the company had "unveiled a new take on it called Quasar," the fourth version of its multi-mode phase pedal2. Delicious Audio states it was the first to publish a demo video of the pedal, filmed at its Stompbox Booth at the show with Brian Marshall, Subdecay's company owner and circuit designer2.
For a player deciding whether to hunt one down secondhand, the short version is this: it is an analog phaser that also functions as an envelope phaser, a step-sequenced modulator and a synchronized phaser-plus-tremolo, all selected from one Mode knob. If you are comparing it against other approaches to the effect, the phaser pedals page covers the type more broadly1.
Videos
Subdecay
Brett Kingman
Michael Fowler
Questions
How many modes does the Subdecay Quasar Phase Modulator V.4 have?
Eleven. Modes 1 through 4 are Cross modulation (X-MOD), modes 5 and 6 are Step Sequencing (STEP), modes 7 and 8 are Envelope (ENV), and modes 9 through 11 are Traditional. The Mode knob selects any of the eleven, paired with a simple control surface of Depth and Offset knobs.
Who designed the Subdecay Quasar?
Company owner and circuit designer Brian Marshall, according to Delicious Audio's coverage of the pedal. Subdecay says it has been designing and building Quasar phasers since 2005, and the V.4 is the fourth version of the line.
Is the Subdecay Quasar V.4 still in production?
No. Subdecay's product page lists the Quasar Phaser v4 as out of production and places it in the discontinued category on its site.
What does the Offset control do in Envelope Phaser mode?
In mode 8, Envelope Phaser, the Offset knob controls the phaser's resting point. The Offset control is mode dependent across the pedal: in mode 9 it controls tremolo depth, in mode 10 it controls the center point of modulation, and Subdecay describes it as setting anything from the phaser sweep center point to synchronized modulation ratios.
Can the Subdecay Quasar do tremolo?
Yes. Mode 4 is described by Subdecay as synchronized phaser and tremolo, combining the two effects together in one mode.
When was the Quasar V.4 unveiled?
At NAMM 2018. Delicious Audio reported from the show that Subdecay had unveiled a new take on its multi-mode phase pedal called the Quasar, and filmed what it describes as the first demo video of the pedal there.
Sources (2)
- Quasar Phaser v4, Subdecay, 2026-10-06
- Subdecay Quasar Phase Modulator V.4, Delicious Audio, 2019-06-06
