Line 6 Echo Pro

One of three units in Line 6's new Studio Modeler line, the Echo Pro incorporates technologies from the company's DL4 Delay Modeler stompbox and Echo

One of three units in Line 6's new Studio Modeler line, the Echo Pro incorporates technologies from the company's DL4 Delay Modeler stompbox and Echo Farm vintage echo plug-in, adds several new algorithms and performance features, and fits it all into a 1U-rackmount box. The Echo Pro covers a lot of ground: in addition to its seven vintage echo-unit simulations, the Echo Pro provides eight Line 6 original echo algorithms, a versatile loop sampler with as much as one minute of loop time, and a bevy of controls for tweaking — and “tweezing” — sounds to taste.


Not exactly known for subtle design, Line 6 stayed the course with the Echo Pro, outfitting the unit with a lime green faceplate and a florid array of lights that includes two bright-red LCDs, a pair of five-segment LED-display level meters, and eight clear-plastic buttons that glow orange when engaged. In addition, three of the Echo Pro's nine knobs are flanked by a host of LEDs that light to show the currently selected setting for their respective knobs. When you power up the Echo Pro, the whole system temporarily goes into Las Vegas mode, creating quite a light show. The overall look is pleasing and fun.

More important than lights, the Echo Pro provides a generous number of controls. Just about every parameter that is likely to be used in everyday operation has an assigned knob or button. That makes the system intuitive and lightning fast to work with. As a result, the Echo Pro is suitable both for studio duties and for real-time performance.

On the left side of the Line 6 Echo Pro are input- and output-level trim knobs and, above them, the aforementioned pair of five-segment input-level meters. To the right of those are three buttons labeled (from top to bottom) Save, MIDI/Sys, and Bypass. (There is also a user-selectable, buffered, all-analog bypass path that is convenient for those using the Echo Pro in front of a guitar amp.) Next up is the Program Select section, which comprises a round LED display and a large knob. The Echo Pro's Program Select section also controls MIDI and system functions. You can save and recall 99 programs and specify particular programs as being the default settings when a particular delay algorithm is chosen — that's a nice feature.

Next is the Model Select knob, which is surrounded by 16 indicator LEDs. Choosing a new algorithm changes the program instantly, without glitching or hiccuping.

To the right of the Model Select knob is the Time/Note window. This display typically shows the delay time in seconds or the tempo in bpm. When you turn other knobs, it changes momentarily to reflect the selected knob's value and then, after a few seconds, returns to showing delay time.

Beneath the Echo Pro 's Time/Note window are three buttons labeled Seconds, Note, and BPM, which are used to control display of time or tempo as well as to select note division of the tempo. That means you can quickly dial in, say, a tempo of 118 bpm and then set the delay to eighth-note triplets. (These three buttons also perform additional roles as record and playback controls for the loop sampler.)

The Echo Pro 's next knob, labeled Time, sets the decay time in seconds or bpm (depending on which you selected in the previous section). To the right of that is the Tap tempo button. I am accustomed to tap-tempo buttons that derive a tempo by averaging the time between the last three or four taps. The Echo Pro's Tap button, however, feels as though it derives a tempo from only the last two taps. That makes it more difficult to set a tempo accurately on the fly.

Beneath the Tap button is a button labeled Global. Pressing this button overrides the time/tempo that is stored within each program with the current time/tempo. (The Global button also doubles as the Half/Speed Reverse button for the unit's Loop Sampler.)

The Echo Pro's next knob, labeled Repeats, controls the number of echo repeats (also known as feedback). The Echo Pro's Repeats are measured on a scale ranging from -90 to +2, which corresponds to the feedback-loop gain expressed in decibels (delay feedback is typically measured as a percentage). Values greater than 0 drive the system into a feedback loop.

Next up are two groovy knobs labeled Tweak and Tweez. These affect parameters of the delay algorithm based on the model selected. One parameter is available to each button per model; when you select a model, the corresponding parameter-indicator LED within the an arcing vertical row of LEDs to the left of each knob lights. In the Tube Echo model, for example, Tweak controls the amount of tape wow and flutter that is being modeled and Tweez controls the amount of tube overdrive. In the Digital Delay algorithm, Tweak and Tweez control bass and treble, respectively. The combination of the various delay algorithms and these two controls allows a wide range of interesting effects to be dialed in quickly.

Finally, a Mix knob provides control of the wet/dry mix, and the Power button turns the unit on and off. A minor quibble: the throw of the power button is shallow, making it possible to inadvertently switch the unit off while adjusting the mix level.


A glance at the Echo Pro's rear panel (see Fig. 1) makes it clear that Line 6 is serious about positioning this unit for the professional market — the unit provides stereo ins and outs on balanced +4 dBu XLR jacks and unbalanced -10 dBV ¼-inch TRS jacks. Plugging TRS cables in to the left side alone lets the unit work as a stereo effects send for other Line 6 products such as the Pod Pro and the Flextone II.

The rear panel also provides an IEC power jack (no wall wart here), MIDI In and Out, and a ¼-inch expression-pedal control-voltage input, allowing more real-time control from a pedal. My biggest gripe about the Echo Pro is the conspicuous absence of digital I/O. AES/EBU in and out would have sealed the deal on this unit as a high-end studio piece, but even S/PDIF would have been welcome.


The Echo Pro provides 15 delay algorithms, including models of 7 vintage devices (see the table “Seven Deadly Simulations”) and 8 Line 6 originals. In ordinary delay applications, each of the Echo Pro's models is very musical. Rather than perfect replicas, however, the simulations can more accurately be described as reminiscent of the real things; they capture the general vibe of the originals, but they tend to be cleaner sounding and more mannered. They are devoid of the messy, noisy, unruly qualities that characterize some vintage units — for instance, the Electro-Harmonix Deluxe Memory Man and Maestro EP-1 Echoplex (qualities that are particularly noticeable when you push those units' parameters to their limits, causing circles of feedback with screaming, grungy modulations). Then again, by never quite letting the system go completely haywire, the Echo Pro kind of saves you from yourself.

The Tube Echo simulation sounds like an early tape-loop delay unit. The echoes round off the high end and get distorted somewhat quickly. As mentioned, you can adjust the amount of tape wow and flutter as well as the amount of tube distortion.

The Multi-Head model simulates a 4-head Roland RE-101 Space Echo, creating warm multitap delays. The Lo Res delay model allows you to simulate an early, low-resolution digital delay. However, it is not gritty or harsh enough for my tastes. The Ping-Pong delay model, on the other hand, creates a beautiful, wide delay with the images bouncing back and forth across the stereo soundscape.

Interestingly, one of my favorite Echo Pro patches is Sweep Echo, an original from Line 6. This algorithm, which adds resonant filter sweeps to the EP-1 emulation, is sure to be a hit with the techno crowd.

The Echo Platter is yet another cool model, based on a strange magnetic-platter echo unit called the Binson Echorec. It creates wobbly, grungy echoes that can get pretty bizarre with all the controls turned up full. The Reverse model grabs a snippet of audio and plays it backward — perfect for psychedelic guitar solos.


Loop Sampler mode, the 16th setting on the Model Select knob, transforms the Echo Pro into a flexible and full-featured performance looper with 60 seconds of loop time (or a full two minutes when Half Speed is selected). It takes a bit of practice to get the hang of, but once you do, the Loop Sampler is a great deal of fun.

Four of the buttons previously mentioned do double duty as controls for the loop sampler; these are labeled Record/Overdub, Play/Stop, Play Once, and Half Speed/Reverse. You start a loop by pressing the Record/Overdub button. When you are finished recording, you can do one of three things: push Play/Stop, which promptly plays back the loop repeatedly without adding to or changing it; push Play Once, which plays the loop back a single time and then stops; or push Record/Overdub a second time, which puts you in overdub mode, allowing you to layer additional material into the loop.

The fourth dual-function button is labeled Half Speed/Reverse. Tapping it once causes the loop to play back at half speed (and thus an octave down). A double tap causes the loop to play backward. You can even use both functions at the same time. Moreover, you can overdub material while the loop is playing backward (or at half speed) and then play it forward again with the new material now playing backward (or twice as fast).

An 800 ms delay is also available while you are in the looper. This delay affects only the layer that is currently being recorded. Therefore, you can record, for example, a backing rhythm with a bit of slapback and then overdub a lead line with a long delay, followed by a percussive element with no delay whatsoever. Great stuff!

Naturally, getting the Loop Sampler to work well requires good timing on the part of the user. This is a device that makes music in the moment — there are no edit buttons, no undos, and no way to trim the edges of the loop. However, all looper controls can be assigned to Program Change commands, MIDI continuous controllers, or MIDI note values, which means they can be triggered from a keyboard instead of from the front panel.


The Echo Pro features comprehensive MIDI implementation, allowing the unit to be controlled through sequencers or external MIDI controllers. A MIDI mapper permits translation of any Program Change number to the 99 programs available on the Echo Pro. In addition, virtually every delay parameter can be controlled through continuous-controller commands. Cooler still, all the knobs on the Echo Pro send out those same controller values. That means you can record delay performances into your sequencer from the front panel of the Echo Pro, tweak them in the sequencer, and have the delays respond accordingly on MIDI playback. Echo Pro also responds to MIDI Clock, letting your delay tempos be set directly from the sequence.

The expression pedal is a real-time delay-morphing control. It allows you to shift between various parameter settings within a given delay model. To set the pedal, you must first move it to the heel position and adjust the settings on Echo Pro. Then you have to move it to the toe position and change the parameters again. Afterward, as you rock the pedal back and forth, it changes the parameters in real time, morphing from the first set to the second. That can make for interesting timbral shifts.


Although I tend to view vintage simulations with a skeptical eye, Line 6 has made me see the light. The Echo Pro has just about everything I could ask for in a digital delay: excellent sound quality, a robust and wide-ranging feature set, and a great, easy-to-grok, real-time, performance-oriented user interface. The loop sampler is easy to use and provides a full minute of sampling time. Dialing in an interesting delay sound is quick and easy. The unit even looks cool.

My only complaints are the lack of digital I/O and the fact that the delay algorithms are not perfect reproductions of the analog effects they are based on (although, admittedly, not all of them claim to be). Just the same, the algorithms all sound very musical, and ultimately, that's what counts. Surely, this terrific-sounding, easy-to-use unit will find its way into many studios and performance rigs. Line 6 has hit one out of the park with the Echo Pro.

Echo Pro Specifications

Analog Inputs(2) balanced +4 dBu XLR; (2) unbalanced -10 dBV ¼"Analog Outputs(2) balanced +4 dBu XLR; (2) unbalanced -10 dBV ¼"Digital I/OnoneAdditional PortsMIDI In and Out; (1)¼" expression pedal; IEC power jackFrequency Response20 Hz-20 kHz (± 0.5 dB; XLR connectors, digital bypass enabled); 20 Hz-20 kHz (± 0.03 dB; XLR connectors, analog bypass enabled)Signal-to-Noise Ratio105 dBAPrograms100 + loop samplerDelay Algorithms15A/D/A Conversion24 bitSampling Rate46.8 kHzInternal Digital Signal Processing24 bitDelay Memory24 bit × 64 megabitsDelay Length2.57 sec. in stereo delay programsLoop Sampler Length59.94 sec. with 800 ms echoDimensions1U × 5.375" (D)Weight3.44 lb.


Line 6
Echo Pro
sampling delay


PROS: Superb audio quality. Intuitive, easy-to-understand user interface. Comprehensive analog I/O. Fifteen algorithms. One minute of loop sample memory.

CONS: No digital I/O. Can be difficult to set tempos accurately using Tap tempo button. Simulations are close, but not completely accurate.


Line 6
tel. (818) 575-3600

Seven Deadly Simulations

Analog EchoBoss DM-2Analog Echo with ModElectro-Harmonix Deluxe Memory ManDynamic DelayTC Electronic 2290 Dynamic Digital DelayEcho PlatterBinson EchorecMulti-HeadRoland RE-101 Space EchoTape EchoMaestro EP-3Tube EchoMaestro EP-1