At the end of the '90s, many guitar players decided to use traditional tube amplifiers and analog pedals refusing the digital processors, racks and MIDI programmable pedalboards used during the '80 and '90 years. The majority of the guitar players wasn't probably looking for a wide range of tonal possibilities: a good amplifier connected to an high quality pedal could provide few but great sounds not available in a digital system. When this trend seemed to be consolidated, new guitar digital systems have been introduced, providing a wide range of realistic sounds generated by the physical modeling technology. In fact, the sounds, generated by mathematic algorithms, were reproducing a realistic tube tone and the built-in knobs (very similar to an amplifier controls) allow a real-time and familiar sound shaping. Yamaha has been one the first manufacturers that introduced in the market the amplifiers simulation based on the ECM (Electric Circuit Modeling) technology. The know-how developed in digital mixing consoles applications and the physical modeling technology built in the early 90's VL series synthesizers have been the first important step in this direction. After the introduction of the DG pre-amplifier and amplifier series (a real breakthrough in matching guitars and digital processors), Yamaha now manufactures a versatile pre-amplifier providing overcoming features: the DG-Stomp.

Functions and Controls
Rear Panel
DG Amplifiers
Technical Details

Convenience. An intuitive operativity and an immediate sound control are the DG -Stomp more significant features: all parameters can be selected thru dedicated knobs or buttons. No motorized controls are available as in the Yamaha amplifiers DG series. Nevertheless, the DG-Stomp clearly displays all parameters available for user-friendly editing. The Manual mode provides quick operativity and programming, including an easy way to save data into the selected memories.

Flexibility. The DG-Stomp is a very flexible unit. A wide range of knobs is available, for effective studio applications. On the other hand, the sturdy structure and the pedals suggest a live use, during performances in which a compact size, easy-to-carry and fully-equipped unit is required. The speaker simulator allows global or individual Program settings, depending from the possible path of the output signal (direct connection to the mixer or to power unit and speakers). Moreover , the preamplifier section can be switched off in order to use the DG-Stomp as an effect processor, connected to external amplifiers or pedals.

Memories and MIDI control. The DG-Stomp provides two areas: Preset and User. Each area includes 10 Groups, each one providing 3 Banks. Each Bank includes 3 Patches. Consequently, the unit provides a total of 90 Preset + 90 User Programs. The User area is dedicated to the user's settings storage. In addition to the parameter settings, a Patch can store also the assignment of external controllers to a maximum of 8 internal parameters. A controller can act via MIDI (or expression pedal input) as a volume pedal (pre or  post preamp, for drive control), a wha pedal (featuring frequency, resonance and on/off switch) or as a parameter remote control (tune and effects).

Sound Quality. Just eight amplifier models can be selected. This could mean a reduced sonic flexibility in comparison with other similar units. On the other hand, the EQ control provides signal processing features that largely overtakes the timbral response of a typical guitar amplifier. There is no clear references to specific amplifier models and brands: the DG-Stomp has been designed to simulate the tube amplifiers characteristics and doesn't provide preset amplifiers tones. The player that likes to program his original sound working on the available parameters will really appreciate this feature (the user interface is really intuitive and user-friendly). The effect section also doesn't reproduce specific models, but provides a versatile array of fully programmable effects. The sound is warmth and realistic, but, sometimes, the attack is too clean and aggressive compared with the sound provided by the real tube amplifiers. Depending on the needs, this feature can also be an useful advantage. The "speaker simulation" section provides many choices. A strong point is the good interaction of the simulator with the guitar speakers, avoiding the risk to radically change the timbral characteristics of the sound. In addition, the DG-Stomp simulations can be successfully used to reduce the noise of the most powerful and bright guitar speakers. This way avoids to choose between line amplification (direct connection) and guitar amplifiers.

Editing. Basically, the unit is user-friendly: the first step is to select an amplifier model, in order to achieve the raw tonal elements. Then, it' time to turn the knobs. Rotating the knobs, the display shows a level range between 0 and 10. When the parameter is modified the orginal value is displayed: rotating the relevant knob doesn't edit the sound until the stored setting has been reached. This safety mode avoids unneeded parameters editing and output signal bounces.

Pedalboard. The built-in pedalboard selects the Bank memories. It enables also the tuner function and allows a direct setting of the delay time thru the "tap" facility, without acting on the front panel. An optional pedal can simultaneously control up to eight parameters, depending on the program settings. Finally, the wah on/off point can be conveniently set along the pedal range for an instinctively familiar approach.

CONCLUSIONS