by Craig Anderton
You love the sound of tubes, but you don’t like being limited to specific cabinets. Or you really like amp sims, but you’re not totally sold on the preamp sounds. Or you love your guitar amp, but you wish it could do more...like split off into other cabinets, or do stereo imaging.
You can resolve all these issues—and more—by combining the best of the physical world (in the form of tubes) with guitar amp sim cabinets. Virtually all amp sims let you bypass the preamps and power amps, leaving you with only the cabinet emulations.
So what do you feed the cabinets? Glad you asked! I have an Orange TH30 combo amp here on loan, with a tube-driven effects loop that features a post-preamp send jack (the entire signal path is all-tube). So, it’s a simple matter to pull out the post-preamp/post-EQ signal (Fig. 1), feed it into an audio interface, and run it through an amp sim cab.
Fig. 1: Like many other amps, the Orange TH30 has a post-preamp effects send jack that you can use to send a tube preamp signal into an amp sim’s cabinet.
As with most effects loops, plugging into the send doesn’t interrupt the signal flow; that happens only if you also plug into the loop receive jack too. Therefore, you can mic the TH30 cabinet at the same time you’re feeding the amp sim. Just note that there may be some subtle timing issues, where the miked sound is a little delayed compared to the direct sound because the mic is a finite distance from the speaker. Nudging the sim sound a bit later in time can solve this; delay it in tiny increments until it sounds "right."
Now let’s take that signal, feed it through a bunch of cabinet simulations, and listen to the results. If you compare them to the original miked sound, it’s obvious the sim versions would be great to layer with the “real” sound, either to beef up the overall timbre, or provide options (like cool stereo imaging) you couldn’t get simply by miking a cabinet. So yes—now I can hear the sound of a TH30 through its 12” Celestion speaker, as well as through a virtual 4 x 12”...or 1 x 10”...or...
|IK Multimedia AmpliTube 3|
Let’s start off with IK Multimedia’s AmpliTube 3 (Fig. 2). AT3 has pretty evolved virtual miking options, as each cabinet can have two mics, two room mics (with variable width), panning, mixing, and the like. You can move the mics closer in or further away to change the sound. Also note that you can put two signal chains in parallel, each with its own cab and miking.
Fig. 2: With AmpliTube 3, you can bypass the preamp/power amp and listen to only the cab.
|Waves GTR 3|
Now let’s turn our attention to Waves’ GTR (Fig. 3). Among other amp options it has a stereo module with two independent amps/cabs, and again, you can bypass the amps to hear only the cab sound. In addition to pan and level controls, each amp also has a delay control and a phase switch. Note that the "HD" switch is enabled in the upper right to give a smoother tone, with the tradeoff being more CPU drain.
Fig. 3: GTR combines two different amps and cabs in a single module, along with miking options.
|Native Instruments Guitar Rig 4 Pro|
Native Instruments’ Guitar Rig 4 (Fig. 4) has several different cabinet options. If you load an amp, it appears along with a matched cabinet. But you can also load a separate cabinet module if you don’t want to use the matched cabinet, or want more flexibility in miking. The matched cabinet offers tone, pan, and "air" controls. Finally, there’s a Control Room module which features a lesser number of cabinets, but adds extensive virtual miking options.
Fig. 4: In this Guitar Rig 4 patch, the signal from the TH30 has been split into two paths, with each one feeding a separate cabinet.
|Line 6 POD Farm 2|
POD Farm 2 (Fig. 5) from Line 6 doesn’t let you separate the power amp from the cabinet, but if you choose cabinet only, the power amp is a clean power amp that has no significant effect on the sound. POD Farm 2 has a dual mode that allows for two independent signal chains. Each amp can have its own miking and amount of “air.”
Fig 5: Here’s an example of Dual Mode in POD Farm 2, using two different amps.
|Studio Devil Virtual Guitar Amp Plus|
Studio Devil’s Virtual Guitar Amp Plus (Fig. 6) has a variety of cabinets. Although you can’t bypass the preamp section, setting it to Classic Clean essentially gives you the cab sound only.
Fig. 6: Virtual Guitar Amp Plus is set to the Green 4 x 12” cabinet.
|Peavey ReValver MkIII|
And last but certainly not least, we have Peavey’s ReValver Mk III (Fig. 7). This sim is unique in that it offers two different cabinet emulation technologies: Speaker Construction Set, and Convolution.
Fig. 7: Speaker Construction Set literally lets you create your speaker cabinet - choose the size, type and number of speakers, mic type, and so on.
I really like the Speaker Construction Set approach, as it’s virtually unlimited. It’s a little annoying that you can’t hear tweaks you make in real time; you have to make the tweak, apply, listen, tweak, apply, listen, and so on. But when you find something good, just save it for next time and you won't have to go through those tweaks again.
The Convolution-based speaker cabinet gives highly realistic sounds, and you can load your own impulses if you want to go totally nuts. While not as flexible as the Speaker Construction Set in some ways, it’s easy to load up different speaker mode impulses so you can decide which one you like best.
This technique is a great way to combine tubes and code, and of course, for live performance it’s a lot easier to carry a small tube amp and a laptop to do your various cabinet sounds. In the studio, this technique lets you multiply one amp sound into many...very cool.
So which cabinet emulations are best? Well, that’s a tough call because each one has standout models, along with other ones I don’t like as much. But, if I change pickups or guitars, sometimes the ones I don’t like come into their own. Also, making one small change with the miking can turn a loser into a winner – or vice-versa.
In any event, this is a fun approach to getting a lot more options – check it out! Also, for additional techniques, check out the article How to Make Amp Sims Sound More "Analog" as this can help create a creamy, warm amp sim tone, and applies to using only cabinets as well as complete amp sims.
Craig Anderton is Editor Emeritus of Harmony Central. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.