The Big Review: Line 6 DL4 MkII – the classic multi-mode delay machine gets more than just a refresh

After an incredible 23 years, Line 6’s legendary delay modeller is making way for an updated version that promises to dazzle us with a host of new tricks.


A solid update that goes big on reverb to keep the godfather of multi-mode delays relevant for the 2020s.
Line 6 DL4 MkII

Isn’t digital tech supposed to go obsolete after a couple of years? Clearly the Line 6 DL4 delay modeller and looper, a staple of pro pedalboards across the world since way back in 1999, didn’t bother reading that part of its job description.

But retirement has come at last for the hugely influential green chunk, replaced by a leaner, more powerful model that aims to take on the new generation by doubling up its delay algorithms and adding a whole bunch of reverbs. So can the DL4 MkII live up to its extraordinary pedigree?

Line 6 DL4 MKII

Well, it’s still green for a start. In fact, in design terms it’s clear Line 6 has been careful not to upset the fans by straying too far from the format of the original pedal.

The slightly daft ‘future retro’ stylings have gone, as has the space at the front for four massive torch batteries (it’s mains only), while the control panel is black instead of silver. But the knobs and footswitches are just as they were in the olden days, including the ‘tweak’ and ‘tweez’ dials that change different parameters depending on the model selected.

Line 6 DL4 MKII

There is, however, one crucial addition to that panel: a little button marked ‘alt/legacy’, which allows you to flip between two banks of delay types on the rotary switch. This means that, as well as the original DL4 sounds – plus looper – you’re getting 15 new ones drawn from Line 6’s HX processors.

Perhaps even more importantly, you’re also getting the unexpected bonus of 15 reverb algorithms, accessed by holding down the legacy button while you rotate the main switch. Line 6 calls these ‘secret reverbs’ but, let’s be honest, that’s just because they couldn’t find room to list them on the panel. Anyway, clearly this is a major addition to the DL4 offering.

Line 6 DL4 MKII

On the subject of additions, the maximum loop time has been bumped up from 28 seconds to four minutes, or two minutes in stereo, which can be expanded pretty much infinitely via the microSD card slot on the back. There’s also an XLR microphone input with its own preamp gain control, plus full MIDI connectivity and, as before, an input for an expression pedal.

We’re itching to get stuck in but there are other features to mention first, courtesy of some global settings accessed by holding down the legacy button and tap footswitch together. Highlights here include a one-switch looper mode (no doubt inspired by the TC Electronic Ditto) and the ability to turn that tap switch into a ‘squeal’ button that momentarily maxes out the repeats. There’s lots more, including comprehensive bypass and dry-through options – you might want to check the online manual for the full list.

Line 6 DL4 MKII

If, on the other hand, you’re a hardened manual-dodger, don’t worry: the DL4 MkII ships with a cheat sheet that goes through the basic controls on one side and lists all the delays and reverbs on the other, along with the ‘tweak’ and ‘tweez’ functions for each of them. It’s a handy little reference tool.

Line 6 DL4 MKII

In use

No record or gig was ever ruined by a bit of background hiss, but that doesn’t stop some of us fretting over the noisefloor in our signal chain. So it’s worth pointing out that, while the DL4 MkII isn’t obnoxiously hissy, it does create a touch more operating noise than the Walrus Audio D1 – and a lot more than Boss’s virtually silent new Space Echo pedals.

Beyond that, our first issue is deciding where to start: reverbs and looper aside, 30 delay algorithms is one hell of a menu. Maybe we should begin by reassuring long-time DL4 devotees that the legacy sounds are all there and sounding the same as they ever did – or possibly a tiny bit better, thanks to updated analogue/digital converters and op amps.

Line 6 DL4 MKII

Actually there is one omission: the less-than-essential Rhythmic Delay model has been replaced by the Binson-inspired Echo Platter from Line 6’s old Echo Pro rackmount processor. But everything else, from the ducking Dynamic mode to the strangely unfriendly Reverse option, remains on board.

A few of the new models are just modified versions of the old ones – there’s a second Memory Man emulation that’s “more authentically matched” to the original Electro-Harmonix pedal, and another Boss DM-2 type with added modulation – and the differences between the various faux-analogue algorithms sometimes feel less than huge.

Line 6 DL4 MKII

But it’s the more ambitious added sounds that really pay the DL4 MkII’s way – especially if you’re using it in stereo. Euclidean mode brings trippy multi-tap textures, Multipass gives extra dynamism to the tone-filtering of the old Sweep effect, and best of all is the randomised octave-hopping of Glitch. Sounding like a defector from the Chase Bliss Habit, this one can get properly riotous with an expression pedal – just note that you’ll need one with a TS output, not TRS.

There’s also a mode called Heliosphere that adds cathedral-like stereo ambience to the repeats – and that brings us nicely to those extra reverbs. They cover all bases, from tasteful plates and rooms to shimmery modulated dreamscapes, and you can route your reverb to go before, after or parallel with the delay. Crucially, the audio quality is excellent, making this a genuine two-in-one stompbox.

Line 6 DL4 MKII

Or should that be three-in-one? Yes, we haven’t mentioned the looper yet. The boosted memory makes this a much more useful performance and composition tool than the one in the old DL4, but in all other respects it’s the same deal – including the ability to halve a loop’s speed or send it into reverse using the fourth footswitch.

Line 6 DL4 MKII

With no screen and no added knobs, the new DL4 remains essentially old-school: like its predecessor, it keeps everything as simple and intuitive as possible for the user. Add some bold new algorithms, a fine reverb section and instant access to three presets – six if you assign the tap footswitch as a bank-flipper – and you have a package whose appeal is obvious.

If your bottom line is pure tone, it has to be said there’s nothing in here that can quite match the hallowed Walrus D1 for sheer prettiness. But if you were already enamoured with the original green giant, you’re going to absolutely love this one.

Line 6 DL4 MKII

Key Features

  • PRICE £279
  • DESCRIPTION Multi-mode stereo digital delay with reverb and looper, made in China
  • CONTROLS 16-way mode switch with ‘alt/legacy’ button for 15 original sounds; time/subdivision, repeats, tweak, tweez, mix; four footswitches for bypass, presets and tap-tempo
  • FEATURES Mono/stereo inputs and outputs, XLR mic input with level control, expression pedal (or dual footswitch) input, MIDI in and out/thru, USB-C for updates and MIDI control, microSD for looper memory expansion; 15 reverbs, 6 presets plus 122 via MIDI, max loop time 240 seconds (mono); switchable true, DSP or buffered bypass, switchable analogue/digital dry path, switchable trails; powered by 9-volt mains supply (included)
  • DIMENSIONS 234 x 114 x 50mm

Like this? Try these