backline engineering

The ZenTone 7 packs a number of tones into its 7 watts, alternating between an EL84 and a 6V6

Download Example 1
ZenTone 7 6V6, 1/4" direct out: Bass 5, Mid 5, Treb 7, bright switch on, Master 6, Gain 4 - single stage, then low-drive dual stage, then high-drive dual; Fender Contemporary Telecaster, bridge S/C;
Download Example 2
ZenTone 7 EL84 1/4" direct out: Bass 3, Mid 3, Treb 5, Bright switch, Gain 4 - first single stage, then low-drive dual; Duesenberg MC Signature, first bridge humbucker, then neck P-90.
Download Example 3
ZenTone7 EL34, 1/4" direct out: Bass, Mid, Treb 9/10; Master 8; Gain 10, high-drive dual stage gain; Gibson LP Studio, bridge pickup;
Recorded in Sound Studio on a MacBook Pro using Digidesign MBox.
Quite often, the phrase “feature rich” (especially when applied to amplifiers) is code for “complicated.” Happily, the ZenTone 7 from Backline Engineering, which sports an impressively long list of features for a small, 7-watt, single-ended Class A design, doesn’t fit in that category—at least not completely, anyway. I was able to get a number of useful tones from it right out of the box. All it took was inserting a supplied set of JJ tubes—two 12AX7s, an EL84 and a 6V6— and it was up and running.

Ideally suited as a studio tool that can also serve as a practice amp with a low-power mode (for tube tone and a nice overdrive at bedroom volumes), the amp is essentially a digitally-controlled device with an all-tube signal path, and offers a great deal of flexibility in terms of applications. Very clever. In addition to a 4- or 8-ohm speaker out, it offers both unbalanced 1/4” and balanced XLR direct outs with an internal speaker load and speaker emulation, so you if you don’t want to hook up a cab and mic it, you can run it right into your interface. If you want to use it on stage, you can send the XLR direct to the board and use the speaker out for an onstage monitor, or use the unbalanced direct out into a clean power amp for a high-volume rig. Talk about flexibility.

In addition to any of the several types of preamp tubes (12AX7, 12AT7, 12AU7, and so on), the octal tube socket also accepts 6V6, 6L6, EL34 and KT77 output tubes without the need for rebiasing. This makes tube substitution is as easy as it could be—a hefty bonus that makes it useful for yet another application, as a convenient tone-testing platform for various members of your tube collection.

At first glance, the front control panel presents a traditional layout, with On/Off and Standby switches, Gain and Master volume controls, and 3-band tone stack of Bass, Mid, and Treble— the Preset control being the only unusual element. The controls are digital, supplying the first twist on traditional here: rather than rolling free through their ranges, each knob has discrete settings as you turn, and an LED readout to let you know where you are in the rotation. There are 16 possible settings for both gain and volume, and 8 each for the tone controls. This design choice offers very precise tone shaping potential, even if it is an unusual way to operate an amp of this type. The second twist on traditional control panels lies in the fact that each knob also functions as a push-button switch for an additional feature: the Master volume control knob doubles as a switch for triode/ pentode operation; pushing in the Treble control knob selects between EL84 or octal tube output; the Mid knob is also bright switch; the Bass, a low-power switch; and the Gain knob controls switching between a single stage preamp, and “low drive” or “high drive” dual-stage preamp.

This is where the clever design of the amp really shows itself. It keeps the visual presentation of options to a minimum, while laying out all the possibilities in one place, leaving the ears and fingers to wander easily through the tonal territory. While it isn’t perfectly intuitive, it is logical and well designed; you don’t have to memorize a manual, or negotiate a mess of switches and gizmos.

Plugging In
As I mentioned, the amp did require some time, and fiddling, to get the hang of—and to find the tones best suited to each of the different guitars I plugged into it: a Fender Contemporary Tele, a Nash S-63, a Duesenberg MC Signature, and an all-mahogany Gibson LP Studio. The good news is that all that fiddling need not be repeated. Once you’ve dialed a tone you find especially likeable, you need only to push the Preset button twice to assign it to any of the 64 available preset locations.

Running through a single 12” FluxTone speaker cabinet, the amp puts out plenty of sound for practice or rehearsal. With the Tele, it served up bright, warm cleans using the 6V6, and the 3-band EQ allowed a solid range of control over the thickness of single notes and strummed chords. With single-coil pickups, I found myself gravitating toward the dual-stage preamp settings, as they were a little meatier, less anemic. Notched Strat-tones were particularly gratifying in the “low drive” stage with the EL84 output selected—just the right mixture of grit and chime for a terrific blues tone that went from thick and kind of jangly to a fat grind with warm, sweet sustain by using nothing but the guitar’s volume knob.

The single-state preamp setting did turn out to be very useful for smooth, mellow clean tones from the Gibson’s BurstBuckers and the Deusenberg’s P-90 and Grand Vintage humbucker. And, after switching out the 6V6 output tube with an EL34, setting the “low drive” Gain about halfway and cranking the Master, the ZenTone did a pretty decent imitation of a much bigger, British-style amp—albeit at much lower volume. I did find myself wishing for just a bit more of the richness and harmonic complexity that a great Class A amp can deliver, but I was nevertheless quite impressed with the ZenTone’s tonal range and precise tone shaping ability.

Recording the amp is a breeze—I ran the unbalanced line out directly into an Mbox, and was immediately rewarded with same tonal range and quality I’d heard through the external speaker. The addition of a line level control to the tone-shaping resources of the front panel made it perfectly easy to dial in just the right amount for any mix. We didn’t have the opportunity to test the balanced XLR output (which is hot) to a mixing board; the Mbox was unable to handle it without experiencing harsh clipping of the line-level input, even on low settings. That said, if you have concerns about the ZenTone 7’s compatibility with your setup or your interface, it’s probably worth contacting Backline Engineering to check with them.

The Final Mojo
The ZenTone 7 is not your ordinary low-power tube amp. While it’s not going to give you exactly the same level of touch sensitivity and tonal vividness as a high-end, handwired EL84 amp, it’s as good at what it does as anything I’ve played recently. If you’re looking to outfit a small home studio, want to avoid creating noise problems for the neighbors, and prefer a range of very useful functions over the perfect solution for one, specific application, the ZenTone 7 provides a great deal of them in a small, well-designed package.
Buy if...
You want a flexible studio tool that's packed with tones and easily adapted to practice, recording and performance applications.
Skip if...
You need the best boutique amp tone money can buy.

MSRP $995 - Backline Engineering -