An integrated 100-watt power amp and overflowing features and effects, make up a potentially perfect do-it-all recording solution.
Excellent sounds. Switchable ohmage. Superb build quality. Good audio interface. Excellent editing software. Extensive MIDI functions. Dual-band impedance selector. Bestows new superpowers on simple, vintage-style amps.
Skimpy documentation. The priciest option.
Boss WAZA Tube Amp Expander Amplifier Attenuator
Boss's WAZA Tube Amp Expander Amplifier Attenuator is a fascinating and ambitious device. It's clearly influenced by Universal Audio's earlier OX Amp Top Box. (See "OX Me Again" sidebar.) But it adds several features not found on the OX—or anywhere else, as far as I know. But first, some basics. (We evaluated the Tube Amp Expander—TAE for short—with its improved version 2 software.)
The TAE is a hefty piece of hardware weighing 15 pounds and measuring roughly 15" x 12"x 4.5". The build quality is superb, with an ultra-rugged enclosure and high-quality pots, switches, and jacks. There's a classy built-in power supply. This a heavy-duty piece of kit—Boss isn't screwing around.
What’s an “Amp Expander?”
Like the OX, the TAE is a rectangular box raised on rubber feet that can perch atop many combo and head-only amps. (It's also rack-mountable.) It, too, is a load box, speaker attenuator, direct-recording preamp, and IR player/loader. We'll cover those functions in a moment, but first, let's zoom in on the TAE's unique and useful "amp expander" role.
All the products covered here let you generate big-amp sounds at low volume. But TAE can also flip the equation, delivering small-amp sounds at high volume, thanks to an integrated 100-watt solid-state power amp. Let's say your favorite amp is a tiny Fender Champ. It's great for recording, but it lacks the muscle for stage use. You can route your Champ's speaker out to the TAE and crank the onboard amp for stage levels that rival a 100-watt stack. (Important: You'll need a speaker cabinet that can handle such levels, which can easily demolish a Champ's humble 8" speaker.)
Like the OX, the TAE includes an effects section offering EQ, compression, reverb, and delay. This provides a virtual effects loop for amps that lack one. If you add Boss's $133 GA-FC foot controller (not reviewed), you can toggle effects on and off and enter delay times by tap. (Most of these functions are accessible via front-panel switches, so a controller pedal isn't strictly necessary.)
So now that simple two-knob Champ includes a high-quality effects loop, a solo boost, footswitch remote control, preset storage, compatibility with many MIDI switchers and controller pedals, and enough onstage volume to compete with macho stacks and heavy-handed drummers. If that's not "amp expansion," I don't know what it is.
Refining Your Rigs
The TAE can store 32 IRs onboard, with more IRs accessible via an attractive, lucid software interface for Mac or Windows. (There aren't yet any editors for mobile devices.) The included IRs are a well-rounded collection of Marshall, Mesa, Fender, Vox, and Freidman cabs in configurations ranging from 1x8 to 4x12. Like the OX, the TAE refers to saved IR/effect combinations as rigs. You can store eight rigs onboard and switch between them without connecting to a computer. You can load your own IRs via a dedicated IR loader app.
The TAE's audio editor boasts a lucid interface with an intuitive signal-flow graphic.
The five microphone models are a Neumann U 87, a Shure SM57, an AKG C451 B, a Royer R-121, a Sennheiser MD 421, plus several combined settings, all with adjustable virtual positions. Additionally, there are four room-mic settings of varied sizes. Sound quality is excellent.
The rear-panel functions are formidable. In addition to stereo XLR output jacks, there's a mono XLR out for feeding the front-of-house mixing desk. The effect loop can be configured as series or parallel. There are full-sized MIDI I/O ports—the TAE not only responds to control messages, but can also transit them to external gear. There's a channel-switching output for multi-channel amps, a stereo headphone jack, and a 4-ohm/8-ohm/16-ohm selector
Another unique feature is a sophisticated impedance selector with independent controls for bass and treble frequencies. This lets you fine-tune the response to suit individual amps. (For example, a low bass-impedance setting can nix unwanted oscillation from ultra-high-gain amps.)
Boss'sWAZA Tube Amp Expander Amplifier Attenuator performs an astonishing number of tasks and sounds great while doing so. The build quality is superb. It boasts unique features, such as its integrated 100-watt power amp and dual-band impedance controls. At $1,338, it's the costliest item in this roundup, and you may not need all its features. But for many gigging and recording guitarists, it could be a perfect do-it-all solution.
Making your amp work for you in any situation.
So you've found your dream amp—kind of. It sounds like a million bucks when it's cranked to its sweet spot, but everyone always tells you to turn it down. And you really want to capture your amp's glorious tone when recording, but you don't want to invest in microphones and preamps, and you don't have an acoustically perfect space to track either. It's an old problem: Guitar amps can be unruly beasts, hard to tame and difficult to mic live and in the studio. Luckily for guitarists, there's a bevy of devices designed to control, capture, and sculpt the tone of any amp.
Load boxes. When using a tube amp, a speaker is usually connected. The speaker dissipates energy from the amp as sound. But what if you want to use your tube amp with no speaker(s) connected, perhaps for late-night silent recording or practice?
You must always have a load of some sort connected to your speaker-out jack, or you can severely damage the amp. This is where load boxes come in: They safely load your guitar amp and allow you to use it in numerous ways with no speakers. Examples of load boxes include the Suhr Reactive Load, Koch Dummybox Studio/PA, and the Two Notes Torpedo Live.
Think of a load box as the most basic form of attenuator, one that lowers your amp's output to line level. Also called “dummy loads," such devices let you take that line out into a computer-recording interface so you can capture and process your amp's sound.
Because guitar speakers are an important component of guitar tone, you usually want to add speaker simulation. Some load boxes have onboard speaker simulations, but if not, you can use an analog speaker simulator like the Palmer PDI09, or a software plug-in that hosts impulse responses. (Such impulse responses digitally mimic the sounds various speaker/microphone combinations.) There are large libraries of IRs on the market, and you can find many more free online. Good IRs sound startlingly close to the real miked cabs.
A load box can also send the loaded-down line-level amp signal to a second power amp, giving you total control over your tone and volume. Crank your amp to the sweet spot, knock it down to line level, add effects if desired, and then “reamp" the whole thing to any volume through a power amp and cab of your choice.
Reamp devices. Some devices let you load down an amp and then reamp it with a second power amp—all in one unit. The Bad Cat Unleash, Fryette Power Station, and Two Notes Torpedo Reload are all good examples. The Unleash and Torpedo Reload perform the reamp function via solid-state power amps, while the Fryette unit features 50 watts of all-tube power. All three units are designed for sonic purity and tonal integrity. But anytime you such introduce devices into your signal chain, tone and feel changes can occur, so try before you buy.
Attenuators. Attenuators passively reduce your amp's volume by absorbing some of the amp's output and passing the rest on to the speaker cabinet. Some attenuators also function as load boxes and feature a output that sends a line-level signal to a recording interface or another power amp for reamping. Examples include the THD Hotplate, the Jim Kelley Power Attenuator, and the Rivera RockCrusher. The RockCrusher load box/attenuator even has a sophisticated analog speaker-simulator with line out, and a graphic EQ to fine-tune the simulated speaker's tonal response.
Reactive versus resistive. When a speaker—let's say in an open-back 1x12 cab—is connected to a tube amp, it has a unique relationship with the amp. Think of it as a back-and-forth conversation between the amp and speaker/cab. Your particular amp, cab, speaker, and what you play influence this dialog. This is called the impedance curve, and it's a measurable variable. Take the same speaker and load it into a closed-back 4x12 cab, and that impedance curve changes. The amp reacts differently than it did with the 1x12. So multiple things affect the tone and feel: amp, cabinet, speakers, and impedance curve.
A reactive load or reactive attenuator lowers or completely loads down an amp's output while maintaining the impedance curve, making the amp feel, sound, and respond similarly to when it's connected directly to a cabinet. Resistive attenuators and loads eliminate that impedance curve. As a result, the tone and feel of the whole rig changes. Most players find that as attenuation increases on a resistive attenuator, the tone is affected, usually becoming more compressed and dark. Transparency is a big plus for me, so I'm a fan of reactive attenuators.
I hope I've helped clarify some of the uses for and differences between load boxes, attenuators, and reamp boxes. Until next month, I wish you good tone!
Record or gig with your favorite amp—minus the cabinet and mic.
Passive speaker-load boxes let you run your amp into a PA or recording input without miking a cabinet. They’re a great way to capture analog amp sounds without hassle—or broken eardrums.
Mesa Boogie’s new CabClone is a particularly nice load box/compensated D.I. at an equally nice price. It’s solidly built in a tabletop format. You can use it with or without a speaker connected to your amp. A wide-ranging level control provides appropriate output for most recording and PA gear. There are phase and ground-lift toggles, and both XLR and 1/4" output jacks. A specialized EQ stage with three voicing options mimics closed-back, open-back, and vintage-style cabinets. There’s also a headphone out for silent practicing or monitoring.
As with many products in this category, CabClone’s cabinet simulations are more like paintings than hi-res photos. They don’t convey the idiosyncratic resonant peaks and phase-cancelled dips of various miked speakers the way that, say, a good set of speaker impulse responses can. But CabClone’s solid, full-frequency tones work well in many contexts, and they respond well to downstream EQ.
CabClone requires no external power. It comes in 4-, 8-, and 16-ohm models, so be sure to get the one that matches your amp’s speaker-out specs.
Test Gear: ’63 Fender Stratocaster, “parts” guitar with P-90s, Ceriatone blackface Champ clone.