You are here

Line 6 DL4 MkII

Line 6 DL4 MkII

Modelling pioneers Line 6 have breathed new life into their ageing delay unit — but they’ve also retained everything that made the original a classic.

I bought the original Line 6 DL4 delay pedal when it first came out — unbelievably, it was some 23 years ago! I used it for several years, both on stage and in my studio, and it remains a popular device, with DL4s routinely changing hands for surprising amounts of money. But a lot has happened in the land of delays since 1999! Notably, IK Multimedia, Strymon, Boss and various others now offer convincing emulations of bygone devices, and there’s been plenty of movement on the looper front too. So it’s probably no great surprise that Line 6 have finally developed a new version of the DL4, or that they’ve included some substantial updates and additions.

In With The New

Cosmetically, the new DL4 Mk pedal looks like an update of the original but with a slightly more compact shape and lighter weight. The distinctive metallic green finish has been retained but the option to run it from batteries has not. It adds several models based on Line 6’s HX effects technology: there are now 30 different delay types in total, comprising 15 ‘legacy’ ones and 15 new, along with looping of up to four minutes in mono or two minutes in stereo. The DL4 MkII also includes 15 so‑called ‘secret’ reverb algorithms, which can be used together with the delays. Why secret? Well... they’re not shown on the front panel.

A new one‑switch looper option joins the classic mode, and for longer loops the maximum loop time can be extended to longer than a typical gig if you plug in a microSD card. I don’t know about you, but I find it hard enough to keep a steady beat for the duration of a 30‑second loop, but greater capacity than you need is no bad thing! Of more practical interest is that while loops stored to internal memory are lost when the unit is powered down, loops stored to an SD card are retained. They’re stored in a proprietary format, though, and if you want to transfer the loop to your DAW you must play it back in real time and record the audio output from the pedal.

There are generous connectivity options: in addition to being able to plug in your guitar there’s a balanced XLR input with a rear‑panel gain control, for use with mics that don’t require phantom power (the Alt button lights up red if the gain is set so high as to cause clipping). Stereo ins and outs are available on quarter‑inch TS jacks, though any combination of mono and stereo ins and outs can be used. The pedal ‘talks MIDI’ for real‑time parameter control, MIDI Clock sync and preset selection: there are MIDI in and out/thru connectors on traditional 5‑pin DIN sockets and USB C, and the latter is also used for firmware updates. A further TRS Exp Pedal jack caters for an external expression pedal, a combined expression pedal and footswitch, or a dual footswitch. These can be set up to change presets, adjust parameters or adjust the looper effects during performance. Note that the expression pedal can be configured to adjust several parameters relating to the current model at the same time. The 9V DC input requires 300mA, and a suitable PSU is included.

The four footswitches are now fitted with Helix‑style coloured halo rings, and the one around the Tap Tempo switch flashes at the current rate. Presets can be saved on board, with six being accessible directly via footswitches in two banks of three, and a further 122 via MIDI. (The factory patches may be overwritten but there’s a process available to restore them, if necessary.) There’s no dedicated bank change button, so the Tap Tempo button has to be redeployed for this purpose via global settings if you haven’t arranged an external means of changing banks or selecting presets.

As is becoming increasingly common in delay and reverb pedals, you can opt for a true bypass which takes the electronics out of the circuit but cuts the delays dead, or a buffered bypass that allows the effect tails to decay naturally.

Set The Controls

On the left is the familiar Model Selector, a rotary switch for selecting the delay type or activating the looper. The addition of an Alt/Legacy button next to this model selector dial essentially switches between the original DL4 settings (shown in green) and the new ones (white), but pressing and holding the Alt/Legacy button while turning the dial gets you into reverb selection mode. Unfortunately, you’ll need to look in the manual or cheat sheet to find out what the various reverb types are, but I suppose there’s only so much you can put on the panel without it becoming too cluttered!

The DL4 MkII caters for mono and stereo I/O, and has an XLR input with gain knob for dynamic mics.The DL4 MkII caters for mono and stereo I/O, and has an XLR input with gain knob for dynamic mics.The rotary controls for Time/Subdivision, Repeats and Mix do as you’d expect but if you haven’t used the original, Tweak and Tweez may not be familiar. These adjust further parameters, but as the parameters vary from one model to another you need to consult the manual to discover what they do. Holding Alt/Legacy and then turning Tweez selects the signal routing for the delay and reverb effects, which can be placed in series in either order or used in parallel. In looper mode, Tweez adjusts the volume of the looper’s echo effect.

Classic looper mode uses all the footswitches to provide dedicated Record/Overdub, Play/Stop, Play Once, Half Speed, and Reverse functions. This mode includes a basic echo effect controlled via the rotary selectors, while the One Switch mode is essentially just record and playback, but still provides full access to the current delay preset and its adjustable parameters. One Switch mode uses the Tap switch, which needs to be reconfigured in the global settings.

The legacy delay models include a lot of familiar favourites based on pretty much every type of analogue, digital, tape and magnetic drum delay, some valve, some solid‑state, as well as adding filter sweep effects, reverse delay and ping‑pong. When it comes to the new delay models, there are several Line 6 originals that variously include pitch shifting, harmony, doubling and step sequencing, but there are also new ‘inspired by’ models, informed by the likes of the TC Electronic TC2290, the Maestro Echoplex EP‑3, Roland’s Space Echoes, the Boss DM‑2 analogue delay and the EHX Deluxe Memory Man. The least conventional is called Glitch, and this one seems to be a type of granular delay with pitch shifting — I had a lot of fun with this one!

The reverb types are generously varied, and cover all the classic spring/plate/spaces bases as well as a few special ones, such as Searchlights, which includes modulation, and Particle Verb, which incorporates some pitch elements. With Alt/Legacy held down, the main controls are used for adjusting the reverb decay, mix, and key parameters such as reverb type and reverb routing.

Worth The Wait?

If you just want a single type of echo, then there are lots of smaller and cheaper pedals that will do the job. The same is true if you only need a looper. Having got that out of the way, though, the DL4 MkII offers an exceptional range of delay types and has the added bonus of some very capable built‑in reverbs. If you’re into ambient music, like me, you can build huge soundscapes by combining some of the less ordinary delay types with long reverbs, and if you like slow‑attack sounds, the Auto Vol setting in the Legacy menu works very smoothly. The emulations of classic echo machines are impressive, and I’ve yet to hear a better reverse delay effect.

I’ve yet to hear a better reverse delay effect.

There’s a great deal to explore here, even before delving into the looper, so for the more experimental musician looking to access a variety of delay and reverb combinations, the DL4 MkII really won’t disappoint. As to the looper, Classic mode — one of the reasons the original DL4 was so highly thought of — works much as before. But now there’s the option of the simpler One Switch mode and, by adding a microSD card, more looping time in either mode than you could shake a forest full of sticks at. It’s great that loops recorded to SD card are saved, too — whether your aim is to trigger them when you next boot up the device, or to transfer them into your DAW.

Any niggles I’ve experienced are pretty trivial in the grand scheme of things: I’d perhaps have liked to see a press‑and‑hold function for the Tap Tempo switch to change banks, and having to refer to the manual or cheat sheet to see what reverb types are arranged around the Model Selector dial isn’t convenient. Other than that, it’s smooth sailing all the way, even when you venture into the murky waters of MIDI.

I was a huge fan of the original and I’m pleased to say that the original Legacy models still stand the test of time, so it was well worth resurrecting those alongside the newer offerings. Both as a studio tool and as a pedal for live performance, the DL4 MkII has a great deal to offer, whether you’re working with guitars and keyboards, mics or whatever. And solo ambient guitar players in particular might find that it is the only pedal they need! This may indeed be a good time to go green...


  • Wide range of delay types.
  • Easy to control.
  • Optional switch/pedal and MIDI connectivity.
  • Looper with an optional microSD card offering huge loop times.
  • Stereo ins and outs.
  • 15 reverb types are available to use with the delays.


  • Reverb types not listed on the hardware.
  • In standalone mode, access to the second bank of presets means reconfiguring the Tap Tempo switch.


Not only do you get some fabulous delay types but there are also esoteric treatments that rival the capabilities of some dedicated granular effects processors. Add in the reverbs and the looper and the DL4 MkII covers a lot of ground, from emulations of classic delay hardware to lush ambient soundscapes.


£334.80 including VAT.

Yamaha Music Europe +44 (0)1908 366 700