The Surgeon Delay is a fully featured, mono, multi-mode compact delay pedal from Matthews Effects, running eight algorithms organized in four groups of two: EQ, Modulation, Auto-Filter and Dual1. It is a digital design, which the maker says delivers "a clean and precise sound that can be fine-tuned to your taste"2. As of late October 2026 the maker's product page lists it as sold out2.
The Surgeon Delay line has carried its medical theme across versions, and the 2022 Surgeon V2 is the eight-algorithm, MIDI-equipped version covered here3. Matthews Effects kept the operating concept consistent across the line: the DOSE knob sets the Dry/Wet blend, and a Tails/Bypass switch chooses whether repeats hard cut when the pedal turns off or continue based on the regen knob setting1.
The controls
The front panel keeps the knob count low, with one knob, MUTATION, changing its job depending on the selected mode1.
| Knob | What it does |
|---|---|
| MODE | Selects the delay algorithm1 |
| PULSE | Sets delay time1 |
| MUTATION | Controls different parameters depending on the mode1 |
| REGEN | Sets the number of delay repeats1 |
| DOSE | Dry/wet blend1 |
| DIV | Tempo subdivisions: 1/2, dotted 1/4, 1/4, dotted 1/8, 1/81 |
The original 2016 Surgeon used the same core names: Pulse controlled delay time up to 1000ms, Dose the mix, Regen the repeats, and a Mode switch moved between the three delay types4.
Two footswitches handle the rest. The Preset/Tap footswitch deals with tap tempo, or, if double pressed and held, scrolls through the first four presets1. A tails/bypass choice sets how the pedal behaves when switched off: Bypass mode hard cuts the repeats, while Tails mode lets them ring out according to the regen setting1.
The eight modes
The eight algorithms sit in four pairs, each pair being two variations on one idea1.
- EQ: an EQ is placed in the feedback loop so repeats continually change character. In LP mode repeats get progressively darker; in HP mode they get brighter1.
- Modulation: Depth mode runs a fixed-speed modulation LFO with depth set by the MUTATION knob; Rate mode fixes the depth and makes the LFO rate adjustable1.
- Auto-Filter: a filter placed after the delay, working like the Mod mode with its own Rate and Synch modes1.
- Dual: two delay taps, with delay 1 in the feedback loop and delay 2 triggered by delay 1. In Free mode delay 2 is independent of delay 1 and unaffected by tap; in Sync mode delay 2 can be set as a division of delay 11.
The 2016 original's three modes map onto the same territory in simpler form. Premier Guitar's announcement described Vicodin as "a dark tape like delay with control over the warble," Morphine as "a standard delay with a wide range of eq going from a dark warm analog voicing to a bright digital delay," and Oxygen as "get experimental with 'Oxygen' by mixing in a auto filter sweep into your delay"4.
MIDI, USB and expression
The Surgeon V2 was announced on 4 June 2022 with an expression jack, MIDI, 127 presets and a computer editor3. It receives MIDI over 3.5mm TRS or via USB, and MIDI controls all of its features and parameters1. It accepts PC and CC messages, so a MIDI controller can switch bypass, jump to any of the 127 presets and drive knobs and features remotely1.
An expression pedal can be assigned to control any or all parameters, with settable start and end points so each sweep has its own toe and heel positions1.
USB does more than carry MIDI. It connects the pedal to the computer editor, and it can power the Surgeon V2 on its own while the editor is in use, though that power is not enough for playing guitar through the pedal1.
USB power is only for editing. For playing, the Surgeon needs its normal power supply; the USB connection cannot run the pedal in a signal chain1.
The Surgeon V2 and its editor
Launching alongside the Surgeon V2 is a computer editor for Mac and Windows. It gives full control for creating presets, editing global settings, adjusting controls in real time and installing firmware updates, and it is not required to use the pedal: everything can be done from the pedal itself1. Guitar.com's coverage of the announcement described the editor as allowing users "to install firmware updates and create and organise presets" over USB3.
The Surgeon sits in a small family of Matthews Effects delay and reverb pedals. The original Surgeon of 2016 covered the three-mode design, and the Cosmonaut V2 reverb/delay carries three cascading algorithms of its own. Matthews Effects later expanded further with The Technician, a dual-channel multi-effects pedal launched in November 2024.
Videos
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Eirik Stordrange
Questions
How many presets does the Matthews Effects Surgeon hold?
The Surgeon V2 holds 127 presets in total. Four of them can be reached from the onboard Preset switch, and the full set is accessible over MIDI, where program change messages jump straight to any preset. The Mac and Windows editor can also be used to create and organize them.
Does the Surgeon have tap tempo?
Yes. The pedal has tap tempo and a tap division control, with subdivisions of 1/2, dotted 1/4, 1/4, dotted 1/8 and 1/8 set on the DIV knob. The Preset/Tap footswitch handles tapping, or scrolls through the first four presets if you double press and hold it.
Can the Surgeon be controlled over MIDI?
Yes. It receives MIDI over a 3.5mm TRS jack or via USB, and MIDI controls all of its features and parameters. It accepts program change and continuous controller messages for things like switching bypass, jumping to any of the 127 presets and turning knobs remotely.
Is the Matthews Effects Surgeon still available?
As of late October 2026 the maker's product page lists the Surgeon as sold out, so new units are not currently on sale direct from Matthews Effects. The original 2016 three-mode Surgeon was an earlier, simpler version of the pedal.
Does the Surgeon work with an expression pedal?
Yes. An expression pedal can be assigned to control any or all of the pedal's parameters, with settable start and end points so each sweep can be shaped to taste. The Surgeon V2 added this expression jack when it was announced in June 2022.
Can USB power the Surgeon?
Partly. When the Surgeon V2 is connected to a computer for the editor, the USB connection can power the pedal on its own. That power is not enough for playing guitar through it, so a normal power supply is still needed for regular use.
Sources (4)
- Matthews Effects The Surgeon Delay, Delicious Audio, 2022-06-18
- The Surgeon, Matthews Effects
- Matthews Effects Surgeon V2 delay has an expression jack and a full computer editor, guitar.com, 2022-06-04
- Matthews Effects Unveils the Surgeon Anatomical Delay, Premier Guitar, 2016-12-28
