Ibanez Tube Screamer

The Ibanez Tube Screamer is an overdrive effect pedal produced by Ibanez which is named for the fact that its light distortion is similar to the sound given by overdriven tube amps. The pedal's sound is different from most distortion pedals as the waveform is compressed with little loss of the original signal, creating a full bluesy tone.

Description

The pedal has an overdrive knob, a tone knob, and a level knob. The drive knob controls the level of distortion, the tone knob adjusts the amount of treble in the sound, and the level knob controls the output volume of the pedal. The pedal can be used on a solid-state amp to try to mimic the sound of a vintage tube amp, although many guitarists prefer to use it to push a tube amp's preamp tubes into an overdriven state. The classic Tube Screamer sound includes a "mid-hump," which means that the circuit accentuates freqencies between the bass and treble ranges (mid-frequencies). Many guitarists prefer this sort of equalization, as it helps to keep their sound from getting lost in the overall mix of the band.

The pedal was produced with many variants. The early incarnations of the TS-808 and TS-9 are the most sought after by collectors, due in part to the fact that Stevie Ray Vaughan is known to have used them as part of his signature sound. Other variants, including the TS-10, TS-7, and TS-5 are less collectible, but contain a nearly identical underlying circuit. The TS-9 and TS-808 pedals have been reissued, but not all of these reissues are using the same parts (chips) that helped to shape the famous tubescreamer sound. Some musicians are having a technician perform modifications to the circuit to improve the sound. In addition, a number of other effects manufacturers make versions of the Tube Screamer circuit, including Maxon (who produced the original Tubescreamer pedals for the Ibanez brand in the seventies and early eighties). In addition, many of the most highly-regarded overdrive pedals, both mass-manufactured and boutique, owe their heritage to the Tube Screamer circuit.

Design

Mr. S. Tamura, the designer of the Tube Screamer, used a subtle clipping circuit to create the pedal's sound. He mixed the input signal with the output signal of the clipping circuit, which "preserves the original dynamics of the input signal which otherwise would get lost at the threshold of clipping.": In this fashion, it preserves the "...original dynamics of the input signal [and] avoids muddiness and vastly improves clarity and responsiveness." As well, Tamura added a "Post-clipping equalization circuit" with a "first-order high-pass shelving filter" that "is linearly dependent on its gain", an approach called "progressivity." [1]