Dual-voice pitch shifter & delay

PurlShift

A few cents.
A lot more space.

Two separately tuned voices, from subtle doubling to harmonies and pitch-shifting echoes. The character of an ’80s digital rack processor, rebuilt from the ground up.

Explore features

Coming soonmacOS · Apple Silicon

Layered / DualEnlarge

Two voices. More width. New harmonies.

Combine pitch, delay and feedback.

DETUNE

Stereo width

Waveforms above and below the dry signal: the left voice is slightly higher and the right slightly lower. L +9 c · 12 ms Dry R –9 c · 24 ms

Small differences in left and right pitch and delay add stereo width to vocals and instruments.

Dry / ProcessedComing soon
HARMONY

Three-part harmony

A piano roll with a four-note melody, a voice a perfect fifth above and another an octave below. +7 semitones Dry −12 semitones

Tune the two voices to different intervals. In Layered mode, blend in the dry signal for three-part harmony.

Dry / ProcessedComing soon
FEEDBACK

A new pitch with every repeat

Raise feedback to send each returning sound through both pitch voices again. In Layered mode, the voices share a feedback input, so their pitch intervals combine over successive repeats. The diagram shows equal, opposite pitch intervals and matching delays.

Dry / ProcessedComing soon

Layered & Dual

The difference is in the input and feedback routing.

Layered

One input, two voices
Layered routing: left and right inputs combine and split into two voices; both feedback paths return to the same summing point. LPitch · delayRPitch · delay Input LInput ROutput LOutput RFeedback LFeedback R

Create two pitches from a combined input. Both voices feed back into that same input, layering more pitches with each repeat.

Delay per voice Up to 1,000 ms

Dual

Two independent channels
Dual routing: left and right inputs each have their own summing point, pitch and delay processing, and feedback path. LPitch · delayRPitch · delay Input LInput ROutput LOutput RFeedback LFeedback R

Process left and right separately. Feedback stays within each channel, so each repeat rises or falls by the selected interval.

Delay per channel Up to 1,000 ms · Feedback stays within each channel

Actual interface · LFO → L PitchEnlarge

LFO

Modulation connections,
at a glance.

Drag a cable to the knob you want to modulate. Here, the LFO controls left pitch. Each cycle moves pitch up and down by as much as 400 c, with the knob’s indicator and value following along.

Waveforms
38 shapes (19 CLASSIC · 19 EXTENDED), from sine waves to ramps and random patterns.
Rate
In Hz or note values synced to your DAW tempo.
Range
Depth and phase. Bipolar or unipolar, with retriggering.

PARAMETER BIND

One knob,
from doubling to echoes.

One Bind knob moves several parameters together over defined ranges. Here, Bind 1 controls right-channel pitch, delay and feedback in Dual mode. At one end is 24 ms doubling; at the other, echoes descending in perfect fifths. Everything between them fits within one turn of the knob—and you only need to automate that one knob in your DAW.

Pitch
R 0 → –700 c
Delay
R 24 → 324 ms
Feedback
R 0 → 55 %
Actual interface · Dual · Bind 1 → three parametersEnlarge

PurlShift
User manual

From initial setup to LFO and Bind connections and saving presets. Find the operation you need in the manual.

Read the manual

Specifications

Audio plug-in for macOS

Operating system
macOS 11 or later · Apple Silicon Tested on macOS 15
Formats
Audio Unit · VST® 3 VST Compatible
Channels
Mono · stereo I/O
Pitch
−2 to +1 octaves
Delay
0–1,000 ms in both modes Independent left/right settings · tempo sync
Presets
53 factory presets · save your own presets
Parameter ranges and features
ParameterRangeDefault
L / R Pitch–2400 ~ +1200 c+9 / –9 c
L / R Delay0 ~ 1000 ms12 / 24 ms
L / R Feedback0 ~ 100 %0 %
L / R Mix0 ~ 100 %100 %
Low Freq · High Freq0 ~ 47 · 0 ~ 412 · 2
Source0 ~ 10094
SustainOff / OnOff
Bind 1–40 ~ 100 %0 %
LFO38 waveforms · Depth · Rate · PhaseTurned Off · 1.00 Hz
LevelsIN · OUT L/R ±48 dB · Trim ±24 dB0 dB
MasterMix 0 ~ 100 % · Out –24 ~ +12 dB100 % · 0 dB
  • Settings saved in DAW projects · parameter automation
  • LFO phase · bipolar/unipolar · clock sync · retriggering
  • Master Mix for dry/processed blending · output and I/O trim
Latency by sample rate
Latency By host sample rate
Project sample rateSamples
44.1 kHz0
48 kHz112
88.2 kHz205
96 kHz224
176.4 kHz411
192 kHz448

Compensation reported to the DAW. Does not include the delay inherent in pitch processing.

CatSiesta · PurlShift

Coming soon

$34 Introductory price

Regular price $49

Enlarged view · drag to pan

Enlarged PurlShift interface

Enlarged view · drag to pan

Cables connecting the LFO and Bind to parameters.

Enlarged view · drag to pan

Cables connecting Bind 1 to right Pitch, Delay and Feedback.