TC Electronic Flashback X4 Delay vs. Line 6 DL4 Delay Modeler

It speaks volumes that the venerable Line 6 DL4 Delay Modeler, introduced in 2000, is still in production.
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IT SPEAKS VOLUMES THAT THE venerable Line 6 DL4 Delay Modeler, introduced in 2000, is still in production. Although there have been significant advances in digital modeling technology throughout the new millennium, and lots of potentially competitive products introduced, the DL4 remains the delay pedal of choice for thousands of musicians. After all, it sports 24-bit processing, true stereo I/O, true bypass switching, 16 delay models, a 14-second looper with reverse and half-speed capabilities, three presets, and a jack for an (optional) expression pedal to enable morphing between settings. The DL4 is also simultaneously versatile and user friendly, and may be powered by either four C batteries or any 9-volt/1200mA source, such as the optional PX-2G adaptor.

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Enter the Flashback X4

TC appears to have had the DL4 in its sights when designing the Flashback X4, as a quick glance at the layout and labeling of the control panel and footswitches will attest (both pedals are also competitively priced at $249 street). Of course, it’s not as if TC is a stranger to delay technology, having engineered the iconic 2290 Dynamic Digital Delay more than a quarter-century ago, and numerous products incorporating delay effects throughout the intervening years—including the compact but featurepacked Flashback pedal from which the Flashback X4 evolved.

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Like the DL4, the Flashback X4 has stereo inputs and outputs that automatically sense whether the pedal is connected in mono or stereo and optimize the sounds accordingly, a choice of bypass types, a choice of 16 delay options, an onboard looper with “play once” footswitch, tap tempo and programmable expression pedal capabilities, and three user presets.

An important difference is that four of the Flashback X4’s 16 delay type options are slots for artist-created TonePrint presets (at press time there were more than 70 free TonePrints available from guitarists such as Joe Perry, Steve Morse, Steve Stevens, Lee Ranaldo, and Bumblefoot). There’s also a USB jack for updating the unit and loading Tone- Prints—though they may also be “beamed in” via a smartphone app—and MIDI In and Thru jacks are provided for selecting presets using an external MIDI controller and/ or syncing to a sequencer or other device via MIDI clock sync.

Additional differences include a rhythmic Subdivision Selector switch that lets you choose either quarter- or dotted-eighth-notes and combine the two using any delay model (the DL4 offers six rhythmic values within the Rhythmic Delay model), an internal Kill- Dry switch that configures the pedal for use in an amp’s parallel effects loop, and 7 seconds of delay as compared to the DL4’s 2.5. The Flashback X4 also comes with a small, lightweight power supply.

Blow by Blow

For the first test, I recorded a short loop of a strummed first-position Gmaj chord onto a DigiTech JamMan looper connected to a Fractal Audio Axe-Fx II set to an ultra-clean preset, and recorded 60 seconds of playback onto a track in Pro Tools 10. Next, I connected the DL4 between the JamMan and the DAW, and recorded the results with the delay both bypassed and engaged (and the Mix control at 50/50%) onto an adjacent track. Then, I did the same with the Flashback X4 (with Delay Level set to 50%). Comparing all three tracks at unity gain, both delay pedals increased the overall level slightly when engaged and when bypassed, and neither compromised the tone perceptibly. Some DL4 users have reported both tone sucking and noticeable level drops when the pedal is engaged, but those weren’t issues with this particular unit.

The second test also involved Pro Tools. Given that several of the presets on both pedals were of roughly the same type (Tube, Tape, Analog, Digital, Space/Multihead, etc.), I recorded about 30 seconds of playing through those presets onto individual tracks for each pedal, and then compared the results. The first thing I noticed was how quiet both pedals were, and how good the delays sounded. The Flashback X4’s dry sound was bigger and fuller, however, and its delays generally more robust and harmonically complex.

Beyond the basic sound, determining which pedal is “better” involves more subjective judgments, and really comes down to individual preferences. For example, the DL4’s Tweek and Tweez controls let you adjust additional parameters within each delay type, which besides enhancing overall flexibility gives you more real-time tactile control. But the Flashback X4’s global Subdivision Selector switch also offers useful real-time tweaking capabilities, especially in the way that it interacts with the other controls, and being able to combine Reverse delay with the Looper provides a cool creative option not available on the DL4.

And speaking of the looping, while both pedals function similarly and offer simultaneous delays and looping, there are important differences. The DL4’s looper includes the now pretty much standard half-speed and reverse functions that are important to many loopists. (They share the same footswitch— tap once for half-speed, twice for reverse—however, which can be problematic. For example, if you are in half-speed mode and press the switch twice for reverse, you hear the loop change back to normal speed for a moment before changing to half-speed in reverse.) The Flashback X4 does not offer either of these functions, but it does allow you to undo/redo overdubs, a highly desirable feature not included on the DL4. Also, the Flashback X4 provides up to 40 seconds of looping time, as opposed to the DL4’s comparatively limited 14 seconds (28 seconds at half-speed).

And the Winner Is …

The Flashback X4 is a fresh, young contender up against a champion 12-year veteran. Both pedals sound great and offer lots of useful features—but the Flashback X4’s overall audio quality advantage, longer delay and looping times, updating (through USB) and TonePrint capabilities, and MIDI functions put it over the top. They also qualify it for an Editors’ Pick Award, which the DL4 received, as well, when it was first released.