Line 6 Farm

You might almost be tempted to buy Amp Farm just for the way in which it graphically models the front panels of all these classic amplifiers!

Pro Tools owners can now reap the benefits of a stack of vintage guitar amps thanks to a new plug‑in from the masters of physical modelling. Paul White tunes up, plugs in and starts cranking up the virtual knobs.

Line 6 are the company who brought physical modelling to mainstream guitar amplifiers, and they're also behind the POD recording guitar preamp reviewed in SOS February '99. Those fortunate enough to run Digidesign TDM Pro Tools hardware can also access this technology in the form of this new Amp Farm plug‑in. One advantage of a software‑based version over the hardware equivalent is that the guitar part may be recorded totally clean, allowing the sound to be changed at the playback stage.

Amp Farm installs from a CD‑ROM with security provided by a floppy disk containing the install key. Users who register their purchase with Line 6 receive an additional key disk. Hardware requirements are a PCI TDM Pro Tools system installed in a suitable Macintosh computer with at least 3Mb of RAM over and above what is needed to run the existing Pro Tools system. The bad news is that Amp Farm can't run on older Nubus Pro Tools systems, though version 1.5 will run on both standard Pro Tools PCI systems and the new Pro Tools Mix 24 package (though not the Windows NT version as yet).

Passive guitar pickups need to run into a high‑impedance input, so you'll need a good DI box to feed the guitar into the Pro Tools interface. Amp Farm may then be set up to emulate any of several amplifier and loudspeaker cabinet types, and, as its effects may be monitored in real time with no appreciable latency, the guitar player is able to choose any amp type for recording without making a commitment as to what amp type will be used when the track is mixed.

The Line 6 approach to physical modelling is based on a very detailed analysis of both individual valve stages and complete valve amplifiers under real operating conditions. Their software then allows the DSP chips on a Pro Tools card to recreate the EQ and overdrive characteristics of any of the modelled amplifiers as well as the frequency response of a number of popular guitar speaker cabinets (miked on and off axis), ranging from a single‑speaker, open‑backed combo to a 4x12 cab. As Amp Farm has no effects other than tremolo and overdrive, some reverb or ambience needs to be added to give the sound a sense of space.

In common with most other TDM plug‑ins, the Amp Farm can be automated, and though there may seem to be little need to automate guitar amp controls, it can sometimes be useful to adjust parameters such as the drive level during a track.

The Models

Because the Line 6 algorithms are modelled after specific amplifiers, these are listed by name in the manual and have grown in number since version 1.0 of the software. The list originally comprised a 1959 Fender Bassman, a 1964 Fender Blackface Deluxe, a 1965 Fender Blackface Twin, a 1960 Vox AC30, a 1964 Marshall JTM45, a 1968 Marshall Plexi and a 1990 JCM800. Now, with version 1.5, there are additional models based on a 1994 Mesa Boogie Dual Rectifier Tremoverb combo, a 1995 Mesa Boogie Dual Rectifier head, a 1989 Soldano Super Lead Overdrive head, a 1987 Soldano X88R Preamp, and a 1996 Matchless Chieftain combo. Of course the trademarks for all these amps are acknowledged and Line 6 are careful to point out that there is no affiliation between the companies mentioned and themselves. These amp models may then be teamed up with any of the speaker cabinet models to provide wide tonal diversity.

Unlike most plug‑ins, which have fairly dull graphics, Line 6 have included representations of the control panels of the amps being modelled, right down to the control knob styles. This takes a little more memory, so it may be advisable to allocate more RAM to the DAE and to run in 256‑colour mode rather than millions of colours.

Using the Amp Farm is just like using a real amp, except the levels and switches are controlled by a mouse. Amp Farm may be patched into any of the usual plug‑in locations, though it's simplest just to use it in a channel insert. As with other TDM plug‑ins, the results are heard while recording, but the audio recorded to disk is unprocessed, so if you want to make the result permanent, you have to record the processed sound to another track. Two menu windows are used to select the amp model and speaker cabinet model after which you just optimise the input level, tweak the controls and play. There is a software input trim control, but for best results, this should be left at its unity gain position and the signal level adjusted at source. A virtual clip LED warns if you overcook the input.

The Line 6 Amp Farm is the most authentic sounding amp‑emulation software I've heard to date — it's extremely close to the real thing in terms of sound and is very responsive to playing dynamics.

When automating the plug‑in, all the controls are available, but to save overcomplicating matters, you can choose just the controls you need from a list and ignore anything you won't want to twiddle. Once the system is set to record automation data, moving the onscreen controls records the moves in the same way as for any other TDM plug‑in. Even fairly fast moves play back smoothly with no obvious zipper noise — you can even bypass the tremolo supplied and emulate a tremolo using the volume control and a very fast mouse hand!

Opinion

The Line 6 Amp Farm is the most authentic sounding amp‑emulation software I've heard to date — it's extremely close to the real thing in terms of sound and is very responsive to playing dynamics. It's probably of most use to those who want to record two or more guitar tracks, then juggle with the sounds retrospectively, because if you're happy to stick with the sound you record with, you could use the Line 6 POD hardware, which is cheaper, has more amp models and leaves your DSP free to do something else. POD also includes effects. Nevertheless, if you need the flexibility of software, including the ability to automate, then Amp Farm is well ahead of the competition.