TECH TIP: Re-Amping Basics for Guitar
By Craig Anderton
Recording your guitar part used to set its sound in stone. Although you could add processors like EQ, reverb, decay, and the like while mixing, they altered the basic sound, but couldn’t provide an entirely different sound.
However, re-amping is a way around this. Maybe you wish you’d recorded through a Vox AC30 instead of a Fender Twin – no problem. There are two main options for changing your sound after the fact: standard re-amping, and using software plug-ins to do re-amping.
Standard re-amping is the more low-tech solution. While recording, you split your direct guitar signal and send one split to a multitrack recorder track (usually through a preamp or other buffer to prevent loading down your pickups), and the other to a guitar amp for monitoring. Monitoring through an amp is important, because the direct signal won’t have any distortion, sustain, or other characteristics that you may need for the right "feel" when playing.
To change the amp sound while mixing, you pad the direct (straight) track down to a lower level suitable for feeding a guitar amp, play back the track through the amp, and re-record the amp sound to a separate track. Another use for re-amping is to add ambience to a direct-recorded guitar part by re-recording through an amp in a particular acoustical space.
Plug-ins (software programs that work with a computer-based host program) are inherently useful for re-amping if you send your straight guitar sound directly into the computer, then get your tone by using the plug-in. But note that recording through a plug-in requires a computer-based host and interface with low latency (delay through the system), otherwise you’ll hear a delay as you listen to the program’s output. Although some guitarists can tolerate a reasonable amount of delay, if it’s much more than 10 ms it’s very distracting. You also need an audio interface with an input designed specifically to accommodate a straight guitar signal, or a preamp if your interface offers only a line level input.
When you record into the computer, the host program records the dry guitar signal, then applies the plug-in to alter the sound. As a result, you can change the plug-in sound at any time, or even use a different plug-in altogether. This means you can make your decisions about guitar tone at any time, even right up to the final mixdown.
Re-amping or using plug-ins does have some limitations. If feedback is part of your sound, there’s no way to create a feedback loop from an amp to a direct-recorded track. This is one reason for monitoring through a real amp, as it can create feedback that vibrates your strings, and the effect on your strings will get recorded in the direct track. Still, this isn’t as interactive as feeding back with the amp that creates your final sound. Plug-ins also have their own limitations; although digital technology does a remarkable job of modeling different amp sounds, purists will always find some subtleties that may not translate well.
Nonetheless, in situations where you anticipate having to make radical changes to your guitar sound while mixing, re-amping is a powerful technique – and now there are more ways to do this than ever before.
