Mattoverse Electronics Warble Swell Deluxe Delay

The Warble Swell Deluxe Delay is a delay pedal from Mattoverse Electronics, hand-made in Wisconsin. Pedal of the Day describes it as an "analog-sounding digital delay" that produces "extremely warm, vintage-ish delay tones," with a modulated, tape echo-emulating character. It is the deluxe version of the regular Mattoverse Electronics Swell Delay, which Pedal of the Day had reviewed a few years earlier.¹

What it does

The pedal sits in the delay family but leans into modulation. Alongside the usual Time, Repeats and Mix controls found on many delay pedals, it adds warble and swell functions that reshape the repeats.¹

The warble side is controlled by a latching footswitch. Pedal of the Day describes the range it opens up: "you can conjure up a wide range of tones, from pseudo-chorus to wild pitch-shifting."¹ Premier Guitar, reviewing the later MkII version of the design, describes the same family of pedals as "a delay circuit with controllable modulation and footswitch-enabled oscillating feedback," with warble controls adding modulation to the delay signal via rate, depth, and waveform knobs.³

Delicious Audio's Paolo De Gregorio sums up the design this way: "It's a vintage-voiced echo/delay with a dynamic foot-controllable Swell feature and gooey tape-like modulation."⁴ On the MkII, he notes the delay times "range from short clean slapbacks to long (up to 800ms) warm analog-esque repeats."⁴

Who it suits

Pedal of the Day's verdict points at a particular kind of player: "Creatives and experimenters will love this one," with the reviewer adding that the real appeal is in the modulated aspects overall.¹ Players after a straightforward, clean delay have plenty of plainer options; this is a pedal built around movement and texture in the repeats.

The MkII version

Mattoverse later refined the design as the Warble Swell Echo MkII, which Premier Guitar reviewed in 2022, calling it "just a delay pedal that warbles and swells."³ The MkII is covered on its own page, and as of October 2026 the maker's product page lists it as sold out.²

Videos

Click to load

Click to load

Click to load