Senior Design Team sdmay18-39 • Sound Effect Devices for Musicians

Project Description

In the audio amplification world, particularly with respect to electric guitar signal amplification, musicians have historically chosen to use amplifiers driven by vacuum tube technology. Up until around the 1970s, vacuum tubes dominated the audio market, and many of the ‘classic’ rock albums listeners hold in high esteem, are recordings of vacuum-tube drive amplifiers. The sonic footprint these albums left on the modern musician is considerable - many guitarists refuse to play with amplifiers driven by tube alternatives – the dominant alternative is the BJT solid state amplifier – solely because of the ‘classic’ tones associated with vacuum tubes.

There are significant advantages to utilizing solid state technology for guitar amplification. Solid state devices are significantly more power efficient than vacuum tubes, and the physical footprint of BJTs in magnitudes or order less than that of vacuum tubes. Additionally, solid state technology is far more resilient to abuse – both physical and electrical – than tubes. Perhaps most importantly, BJTs are significantly less expensive than vacuum tubes.

Despite the leaps and bounds made in BJT technology (in efforts to model the tube amp), and despite the considerable financial benefit to producing solid state amplifiers on a commercial scale, solid state technology still, for the most part, plays second fiddle to vacuum tubes among professional musicians. We believe this is large due to a failure to properly address the sonic aesthetics surrounding vacuum tube amplifiers.

We believe that, if the key musical parameters around the tube amplifier are quantitatively observed, a tube ‘effect’ can be digitally or analog-ly generated and superimposed onto the signal entering any run-of-the-mill amplifier (solid state, or otherwise). This effects module, along with generating the tube tone, could incorporate other desirable effects such as overdrive, reverb, tremolo, etc. In our proposed solution, we have a small form factor effects module that can superimpose desired effects onto the incoming signal, and then overlay the tube sonic qualities onto the signal prior to output into any amplifier-speaker system. This solution offers an all-in-one module that addresses the tone demands of guitarists, while maintaining a comparatively less convoluted and expensive package compared to a boutique vacuum tube amplifier and effects pedalboard rig.