This online bonus material supplements the Waves GTR3 review in the April 2008 issue of Electronic Musician.

The Waves/PRS Guitar Interface

Previous versions of Waves GTR always included the Waves/PRS Guitar Interface (WPGI), but GTR3 lets you choose a package with or without the interface (see Fig. A). The WPGI is a DI/preamp (and not an audio interface) that connects directly to your computer. It is designed to convert your low-output, high-impedance guitar-pickup signal into a low-impedance, high-output balanced signal ready for a balanced mixer or an audio-interface input. The device gets its power from two 9V batteries (included) or a 12 VDC adapter (not included).

FIG. A: The Waves/PRS Guitar Interface converts your passive guitar-pickup signal to a low-impedance, high-output signal optimized for your mixer or audio interface. The interface is available either by itself or bundled with the Waves GTR3 software.

The WPGI''s 1 MΩ 1/4-inch unbalanced input is impedance matched for passive guitar pickups. The output can be either a balanced XLR or an unbalanced 1/4-inch signal. You can set the XLR output to either line or mic level. The WPGI offers a ground-lift switch for defeating ground-loop noise; my guitars have humbucker or FilterTron (hum-canceling) pickups, but I''m sure this feature will be quite useful with single coils. I''m a firm believer in meters on hardware devices. Sadly, the WPGI''s Gain knob doesn''t offer gain-scale or any other indicators. The three level-indicator LEDs tell you if a signal is present, if that signal is at a nominal level, or if the signal is overloading. I would have preferred at least six-LED metering calibrated in decibels and a dB scale around the Gain knob.

I also wish that the WPGI offered a direct USB connection to the computer, like on the DI that Line 6 includes with its software. This would have made the WPGI far more useful in live situations. And I was disappointed by the lack of a 1/4-inch TRS balanced output. Waves recommends sending a balanced line-level signal via its XLR output, but the line-level inputs on most audio interfaces have TRS jacks.

Sonically, the WPGI held its own against high-end hardware DI boxes, emitting a strong, clean signal. If you''re going to buy a Waves GTR3 package and don''t already have a high-quality DI, you might want to get the WPGI with your software. But be aware that you''ll still need an audio interface and perhaps some conversion cables.