News & Reviews
> Genz Benz ShuttleMax 12, 410T-UB, GB212T-UB
> Genz Benz Shenandoah Compak 300 Combo
> Acoustic Guitar Shen Pro LT Review
> Bass Player Shuttle Series Review
> Guitar Edge Shenandoah 150LT Review
> Shen Pro Wins 'Platinum Award' from Guitar World Acoustic
> Shenendoah Stereo 60 Review
> Guitar One El Diablo 60-TS Review
> Music Maker El Diablo 100 & GBE 600 Reviews
> Guitar One El Diablo 100 Review
> Bass Player NEOX400-112T
> Guitar Player El Diablo Review
> Guitar Player Shenendoah 200 Review
> Bass Player GBE 600 Review

March 01, 2004
Guitar Player El Diablo Review

Reprinted by permission from Guitar Player magazine, March, 2004 issue

Tested By Terry Budding

Genz Benz was a noted maker of speaker cabinets and equipment racks before introducing its first amplifier in 1997 - a modestly powered bass combo. Soon, the company’s bass amps became bigger and more powerful, and the product range expanded to include amps for keyboards and acoustic instruments. Curiously, though, guitar amps remained conspicuously absent from the line. That void has now been filled in a big way with the introduction of the fire-breathing, 100-watt El Diablo—a dramatic entry into the high-power guitar amp arena that’s brimming with cool features and innovative circuitry.


With its gleaming metal faceplate, industrial-strength Edge-Lift handles, and eerily illuminated tubes, the aggressively styled El Diablo casts a menacing visual presence upon a darkened stage. But don’t be deceived by its sinister appearance. Yes, the amp’s Hot channel is optimized for wickedly scooped nu-metal tones, but its Warm channel can produce heavenly vintage-vibed tones, as well.

The El Diablo’s Warm channel features Gain and Volume controls, plus a footswitchable Clean/Vintage gain-boost function. Clean mode offers the most headroom, and Vintage mode provides a moderate gain boost for more overdriven textures. The Warm channel also has a dedicated Reverb control.

Now here’s where things get interesting. Instead of a traditional passive tone-control circuit, the El Diablo features active tone controls that can provide as much as 15dB of boost or cut. This fresh approach to preamp design combines the compelling distortion, dynamic, and textural characteristics of tubes with the broader tone-shaping range available from active EQ circuitry. Props to Genz Benz for cleverly combining the strengths of both technologies.

Optimized for high-gain tones, the Hot channel has one more tube gain-stage than the Warm channel. As with the Warm channel, it also features independent Gain, Volume, Reverb, and active tone controls. But the Hot channel has a few more tricks up its sleeve. For starters, it sports two footswitchable options. For maximum overdrive, the Classic/High Gain switch provides extra boost in High mode, and the Texture switch engages a unique, high-voltage zener-diode asymmetrical clipping circuit in Compressed mode. Besides enhancing sustain (as you’d expect from a compressor), the Texture circuit also adds an aggressive bite to the tone - something more akin to the grind from a distortion pedal.

The Hot channel is also equipped with an unusual control labeled Tube Contour. This single-knob passive circuit is similar to a vintage-style tone control network, except its special dual-ganged pot controls bass and treble frequencies simultaneously. Turning the knob clockwise increases the bass and treble content (with an accompanying midrange dip), and counterclockwise rotation reduces the bass and treble and adds a midrange emphasis. The organic-sounding Tube Contour control can provide an extra dimension of cool tone shaping possibilities as it interacts with different Gain and Texture switch settings. Unfortunately, it’s not footswitchable.

The El Diablo’s two preamp channels share a footswitchable global Attack control. This active boost circuit is voiced lower than a conventional presence control to enhance bite, edge, and cutting power. It uses a solidstate op amp to boost the upper-mids and lower-treble, and, unlike the Gain and Texture functions, the Attack control is equipped with a knob that lets you dial in the precise amount of narrow-band boost.


I began my sound tests by exploring the Warm channel in search of some sweet clean Strat tones. I was immediately rewarded with some crackling-crisp bridge-pickup country tones that cut like a finely honed blade as I tweezed in some bite with the Attack knob. The headroom seemed almost limitless, and the dynamic response was firm and controlled without feeling stiff or stubborn. The reverb produced an expansive ambiance that sounded more like a tightly damped studio plate reverb than a sloppy surfsoaked tank. Switching from Clean to Vintage mode, I was able to extract some mildly overdriven lead tones that responded well to picking attack and guitar-volume changes.

Switching to a PRS McCarty to test the Hot channel’s heavier tones—and with the Gain and Texture switches set to Classic and Dynamic—the El Diablo served up a heaping helping of impressively firm and focused low-end chunk that sounded especially deep and powerful through its companion G-Flex cabs (see sidebar). Even sadistically low alternate tunings rendered chugging, forceful rhythms that retained a deep, percussive tautness. And yes, the active tone controls have more-than-sufficient range to elicit savagely scooped nu metal tones. Maximum heaviness ensued when the High Gain and Compressed switches were engaged—both chords and single-line riffs burned with limitless sustain while I tweaked the Tube Contour control to manipulate the amp’s harmonic balance.


Considering its impressive abundance of powerful and useful tone-shaping features, it’s obvious that a lot of R&D time was spent making sure the first Genz Benz guitar amp would be a success. El Diablo’s synergistic blend of tube and active-filter technologies could be an inspiring bellwether for future amp developments. It’s amazing to realize that after decades of innovative guitar amp designs, there are still plenty of possibilities remaining to be explored.


The Genz Benz GB 412 G-Flex ($1,100 retail/$880 street) and GB 212 G-Flex ($687 retail/$550 street) cabinets feature four tuned ducts below their angled baffles. This type of ported design extends the cabinet’s low-frequency response to provide the massive low-end desired by today’s rock and nu-metal players. Both cabinets are loaded with the same 75-watt GenzBenz GBE 1240-V75 speakers (made by Eminence). The cabinets are constructed of birch plywood—except for the MDF baffle board, which is angled or “flexed” nine-degrees to increase the cabinet’s horizontal dispersion and reduce tone-robbing internal standing waves. The cabinets can be operated in mono or stereo, depending on which input jack you choose. They also come with hip, removable casters.

If you thrive on tones with huge low-end, these cabs are for you. Not surprisingly, the 4x12 sounds significantly louder than the 2x12, with more room-filling presence. But the smaller 2x12 is not without its own brand of charm. It possesses a stouter voice with a thicker midrange bark, and thanks to its less efficient nature, can be pushed harder to produce more raging tones at lower volume levels—just the ticket for small club gigs. Either cab can produce a powerful low-end thump that can make a conventional sealed cabinet sound pitifully weak in comparison. Make no mistake, these cabs aren’t for sensitive wine sippers. They’re rude and mean and ready to rumble.

2019 © KMC Music Inc., All Rights Reserved
As part of our commitment to improve design and quality of our instruments,
Genz Benz reserves the right to change pricing and specifications without notice.
Terms of Use | Privacy Policy