Q. Can I plug my guitar into the computer?

Guitar Audio Interfaces

You could plug an electric guitar jack directly into the microphone or line input jack of a computer and it may record a sound.  But it will probably be a really awful sound, not at all what you expected.  There are three reasons:

First, most guitars do not output a strong enough signal for a line input, so the input would require extreme volume boosting – which also boosts all the noise, static and hum that is present.

Second, an electric guitar pickup is a dynamic electromagnetic system, it reacts to the magnetic pull of the vibrating strings in combination with the load of the input that it is plugged into. A guitar amp input has a certain impedance (resistive load) that it contributes to the circuit formed between the amp and the coils of the pickups. High-impedance guitar inputs on amps and effects are typically between 250 K Ohms and 1,000 K Ohms. If the guitar is plugged into a line input (typically 10 K Ohms impedance) or a mixer mic input (typically 1.5 K Ohms), the impedance is way too low and this changes the sound being produced by the pickups into a thin, tweezy, 90 lb weakling of a guitar sound.

Finally, the characteristic sound of an electric guitar is not just the string sound coming off the pickups, it is the coloration that the preamplifier and amplifier circuits add (including distortion, EQ and compression), the sound of the speakers and the speaker cabinet, the sound of the room and the microphone(s) used to record, and the sound of any other effects that the guitarist adds.

The classic way to record an electric guitar, if you have a microphone and a recorder or audio interface is to set up a ‘live’ performance rig, with amp and effects as you would normally play them, and a microphone or two in front of the speaker. Make sure the amplified sound in the room in what you want, and then move the microphone around in front of the speaker cabinet until it picks up the sound that you want.  A typical position for the mic is 4 – 12 inches away from the speaker, slightly off center from the speaker cone. Moving the mic as little as an inch will make a difference in the tone, so experiment until you get the optimum sound.  The drawback of the classic approach of course is that you have to play at performance volumes to get the best tone out of the amplifier.  This is not an option for apartment dwellers and those who don’t want to get evicted for cranking up the Marshall at 2 in the morning.

In order to record a convincing electric guitar sound, we need to treat the input signal correctly, and replace the various steps in the process that make up the sound.

One of the tools in our bag of tricks is the software amp simulation, software that mimics or models the characteristics of the preamp, amplifier and speaker cabinet. When the raw guitar sound is fed into the simulation software, the output should be a convincing replica of the guitar through an amplifier.

Here are some alternatives that go for recording the tone, without the ear-shattering volume.

Guitar USB interfaces are the simplest recording solutions, a jack that plugs into the guitar, with a USB connector on the other end to plug into a computer. This eliminates the need for a separate digital audio interface, and is available at a low cost.

Alesis

• GuitarLink as simple as it comes, a cable that hooks a 1/4″ guitar plug to a USB jack to record into a computer. GuitarLink $55
• GuitarLink Plus – The GuitarLink hardware with a starter edition of Native Instruments GuitarRig LE simulation software GuitarLink Plus $92

Apogee

• GIO A floor based ‘pedalboard’ style controller with footswitches and USB comnputer interface, together with simulation software.  This is on the expensive side of the dedicated guitar interfaces. Macintosh only, OSX 10.5.7 and later.
• Jam – an inexpensive guitar USB interface for Mac and iPhone/iPad Macintosh OSX 10.6 and iOS 4.3 and later only. No software included, it is designed to work with GarageBand’s guitar amp simulations.

IK Multimedia

• Amplitube iRig This outrageous little hardware/software combo uses your iPhone or iPad as the processing engine to generate amp and effect simulation for guitar and bass  Amplitube iRig $45
• StealthPlug one of the first plug and play guitar recording setups, 1/4″ plug to USB for guitar and bass. Comes with a starter version of IK’s Amplitube simulation software.
• StealthPlug Fender Studio The Stealth plug interface with a software package of licensed Fender amp simulations. StealthPlug Fender Studio $157

Line6

• GuitarPort XT a ‘stomp box’ style box with a 1/4″ jack and a USB connection, with Line6 amp simulation software. The XT version adds GearBox additional models and Mac OSX support to the original GuitarPort.

Miditech

• GuitarFace USB interface box with one guitar and one mic/line input, bundled with Amplitube software. Windows only

Native Instruments

• GuitarRig Mobile portable USB interface box with up to 24 bit /192 KHz audio conversion and GuitarRig 4 Essential simulation software
• GuitarRig Kontrol Edition Pedalboard controller with volume/control pedal, audio interface, and GuitarRig 4 simulation software $499

Peavey

• AmpKit Link Another amp simulator that uses an iPhone for running the simulation software

Vox

• JamVOX USB interface with 2 3 inch speakers built in, and Vox simulation software

Guitar software amp and effect simulations – Computer modeling software for use with already-recorded tracks in a Digital Audio Workstation (DAW) program, or for use with guitar that is being input through an audio interface.  Some of the software can run stand-alone, but most are plug-ins for DAW software, so they need the DAW program, or a plug in ‘shell’ program to act as a host.  Check the compatibility with your DAW first before you buy. Plug-ins come in several formats – VST (Cubase and many others), RTAS (Digidesign ProTools n0n-HD versions) and Audio Units (AU, Apple Logic and GarageBand).

Avid/Digidesign

• Eleven and Eleven LE RTAS plug-in for use with ProTools LE and ProTools M-Powered

IK Multimedia

• Amplitube 3 well respected amp and effect simulator, there are optional model packs available for Fender and SVT amp simulations.  AU, VST and RTAS formats, Mac intel only, OS X 10.5 or later or Windows XP, Vista and Windows 7, 32 and 64-bit  $349

Line6

• PodFarm 2 Plug in AU, RTAS and VST, Mac G5 or Intel, OS X 10.4.6, Windows XP (SP3) and Vista, 32 and 64-bit (Windows 7 compatibility not stated)

Magix/Samplitude

• Vandal VST/AU amp simulation plug in Vandal $264

Native Instruments

• GuitarRig 4 Pro Perhaps the most comprehensive of software guitar modeling systems. Available as a component of Native Instruments software bundle Komplete Komplete 7 $599
  Mac intel only OS X 10.5 or 10.6, Windows XP (SP3, 32-bit only) Vista and Windows 7 (32 and 64-bit)  Stand-alone, VST, AU, RTAS (Pro Tools® 8 and higher), ASIO, Core Audio, DirectSound, WASAPI
• GuitarRig 4 Kontrol Edition Pedalboard controller with volume/control pedal, 24 bit / 192 KHz audio interface, bundled with GuitarRig 4 Pro software Guitar Rig Kontrol Edition $499

Peavey

• Revalver II Revalver has many fans and positive reviews, especially for its tube amp simulation of blues guitar tones.

Studio Devil

• AmpModeler Pro VST, AU and RTAS plug in

Waves

• GTR3

There is an online forum dedicated to guitar amp modeling

Guitar hardware amp simulations

There is a wide variety of stand-alone guitar hardware effects boxes that have amp and distortion simulation (along with dozens of other effects). Some of these are also USB audio interfaces. But all of them would be suitable for treating the guitar signal before inputting to an analog line level recording interface or a mixer. This takes care of potential impedance and level mismatches because the hardware effect gives the guitar a high impedance input, and outputs a low impedance line level signal to the recording input.

Avid/Digidesign

• Eleven Rack High-end rackmounted hardware modeling system with two 1/4″ and one XLR microphone input. USB audio and MIDI interface compatible with ProTools (Comes with ProTools 8 LE) Digidesign Eleven Rack $871

Boss/Roland

• GS-10 compact modeling pedal with USB output for recording
• Roland VG99 Guitar System – a very comprehensive guitar modeling system

Digitech

• RP155 Compact modeling pedal with USB output for recording
• RP255 modeling pedal with USB, adds volume/control pedal
• BP355 designed for bass, with volume/control pedal and USB
• RP1000 high end pedalboard style hardware modeling and recording system

Korg

• Korg’s AX series and Pandora series modeling pedals don’t offer USB audio interfaces

Line6

• M5 Stompbox Modeller
• M9 Stompbox Modeller
• M13 Stompbox Modeller
• The Pod HD 200, 300 , 500 series pedalboard style modelers the FloorPod Plus, Pod 2.0 and PocketPod do not have USB recording interfaces, where they have USB ports they are for MIDI or software updates only
• Pod HD, PodX3 Pro and PodX3 The latest editions of the Line6 Pod, the granddaddy of desktop amp simulation hardware, these model have USB audio interfaces.

TC Electronics

• The G-Sysem and Nova floor pedalboard style modelers don’t have USB audio interface capability

Vox

• ToneLab EX and ToneLab ST pedalboard modelers with tube preamp, volume/controller pedal and USB audio interface

Samson / Zoom

• G2.1umodeling pedal with volume / control pedal and USB interface
• G3modeling pedal with USB interface and 3 LCD displays
• G9.2tt Pedalboard style modeler with two volume / control pedals

See companion article on Recording software

See companion article on Audio interfaces