IS IT BOLLOCKS?

Is it really possible for a man to McFly?

In Back To The Future, Marty McFly turns up his guitar amp so high that it blows him across the room. Can you really rock loud enough to be knocked off your feet?

PAUL RIARIO, TECH EDITOR, GUITAR WORLD

WHAT? CAN YOU REPEAT THE QUESTION? Oh! Got it. Well, the simple answer is there is no commercially available guitar amplifier that can be pushed loud enough to even come close to physically knocking you off your feet. Indeed, Back To The Future’s CRM-114 amp is fictional. Generally, the loudest valve-powered amps are rated at 100 watts – they’re mostly engineered for cleaner headroom and tighter bass response, as opposed to sheer volume, even when pushed to overdrive.

You could make a case for greater power when bands needed amps to compete with drums and crowds back in the ’60s and early ’70s, when PA systems weren’t as sophisticated as they are now. Ritchie Blackmore, for example, was known to crank a 200-watt Marshall Major for his sound (rather than to blow back Deep Purple fans).

But when does loudness actually start to have a physical effect? At 120dB, according to the Decibel Equivalent Table, you’re front row at a blaring rock concert. Permanent hearing loss begins at 127dB, glass shatters around 163dB, and if you want to really go flying off your feet, a 183dB sound wave should do the trick, acting like a 289km/hr blast of wind. Any volume higher will result in eardrums rupturing. Fortunately for Marty, his amp couldn’t reach the more intense decibel levels, because if it did, there’d be no going back to the future.