The effect treble frequencies have on the tone of guitar amplifiers
How’s it going? This month we’re going to look at the effect that treble frequencies have on guitar amps and just why they’re so important to the overall tone you’re seeking in an amplifier, to begin with. The desire for more treble in guitar amps started way back in the infancy of tube amplifiers designed for electric guitars. In the beginning, and throughout the evolution of his amp line, Leo Fender was always asking working musicians what they thought of the amps he manufactured. It turned out that most of them wanted a brighter, snappier tone to suit the musical styles of the day (e.g. the type of popular “country and western” music heard back in the late ‘40s). The first Fender amps were voiced directly from the opinions of the musicians who played them. Eventually, Fender amps found favor as the perfect match for the Fender Broadcaster (and many other brands of electric guitars). This increase in brightness worked well for country and jazz styles alike, where there was a need for more definition of tone.
As American music evolved and rock and roll was invented, ears all over the globe heard and embraced this exciting new form of musical sound. You could say that our ears had become “biased” toward what we were hearing over the airwaves, and this was certainly the case in the United Kingdom and Europe as well. Listeners the world over were hearing for the first time that pleasingly bright tone from the imported American records they bought from their local record shops. But there was a slight problem with amplifiers made in Britain—they were too dark sounding when compared to the American sound that was being spun on the turntables across the Atlantic. In Britain, and Europe too, it’s very conceivable that the first guitar “effects” units were the treble boosters made by a few companies in Britain, like Dallas Arbiter and Hornby Skewes, to name only two such manufacturers. The reigning king of the treble boosters is most likely the Dallas Rangemaster unit. However, there are some others that are equally engaging in tonal quality.
There is also quite a list of top British guitarists who used treble boosters in conjunction with a variety of English amplifiers, such as Eric Clapton’s Marshall 2x12 combo (recorded using a 1960 Gibson Les Paul during his seminal stint with John Mayall and The Bluesbreakers on the Beano record from 1966) and Ritchie Blackmore’s vintage dot-neck ES-335, which was plugged into a Hornby Skewes treble booster seen sitting on top of his VOX AC30 during the “Double Concerto” footage from Royal Albert Hall. I believe that Ritchie’s solo on Deep Purple’s first hit single, “Hush,” used this same rig. It sure has the same tone and attitude! This rest of the list includes everyone from The Shadows’ Hank B. Marvin to Ireland’s Rory Gallagher, from Black Sabbath’s Tony Iommi to Queen’s Brian May, and pretty much everyone in between.
I’ve found that the vast majority of players who favored original Vox AC30s actually plugged into the Normal channel rather than the brilliant, but louder, “Top Boost” channel. What could be the reason? If you’ve ever had a chance to plug into the Normal channel of an original AC30, one of the first things you noticed is that the sound is indeed darker, and yet it has much more girth than the brighter “Top Boost” channel. In order to bring out that girthy tone you have to add just a bit of optimized high end from a treble booster— to give it a bit of clarity and definition. The Normal channel is dark sounding because in the actual layout of an original AC30 the drive tube (V4) is split between the two channels, and the Normal channel side doesn’t include the treble and bass controls. Instead, only the “Top Boost” channel inputs have full control over these two tone controls—and the “Cut” control as well. By the way, the “Cut” control does work with the Normal channel, but even so, it’s best to use a treble booster here and set the “Cut” control where it sounds good to your ear and simply leave it there. Your choice of instrument will also guide where you set the “Cut” control.
Okay, so now you can really listen to those old classic records and know why they sounded so great to start with. There are so many tones you can pull off from those old records with some careful tweaking of the proper instrument and amplifier, along with a few well-chosen stompboxes. And, you can get very close to the original if you choose the right stuff. Remember, this stuff doesn’t have to cost an arm and a leg. I get a pretty convincing VOX tone from my old beloved Peavey Classic 30 combo. Next month, I’ll tell you how you can nail this great old sound with a wonderful pedal that I’ve recently discovered. See you next time.
Dean Farley
Dean is the chief designer of "Snake Oil Brand Strings" (sobstrings.net) and has had a profound influence on the trends in the strings of today.
