The power of screamer- The Ibanez Tube Screamer!


I wanna talk a bit about voodoo child... yea, like the hundredth time! But this time I am not talking about Jimi Hendrix’s voodoo child but its cover by the legend Stevie Ray Vaughan; a genius musician, singer, songwriter, and record producer. In spite of a short-lived mainstream career spanning seven years, he is widely considered one of the most influential electric guitarists in the history of music, and one of the most important figures in the revival of blues in the 1980s.

About that song again; you know what? You may know to sing its lyrics throw the feel and shred the tabs; but I am kinda sure you don’t know how to sound like it! Ha? Gotcha! Anyways enough of show off, Let me tell you how you get that classic sound used by Trey Anastasio (Phish), Gary Clark Jr., The Edge (U2), Noel Gallagher (Oasis), Kim Gordon (Sonic Youth), Buddy Guy, Kirk Hammett (Metallica)... I know it’s pretty long list... Greg Howe, Joan Jett, John Mayer... You still want me to continue?  I better tell you the grand solution instead; Its Ibanez tube screamer; better known as Ibanez TS9.

Tube Screamer is an overdrive/distortion pedal that is mild compared to many, but allows the true sound of the guitar and player's technique to come through. The most popular use of a tube screamer is to push a tube amp to make it overdrive more, but they sound good through almost anything.

The first Tube Screamer was the green TS-808 overdrive pro in the late '70s. It was preceded by the Orange "Overdrive" and green "Overdrive-II" which came in narrower boxes without the battery cover, and the reddish "Overdrive-II" which had a box very similar to the TS-808. The lighter green OD-855 Overdrive-II is also in the TS-808 style box and has a circuit which is similar to the 808 - the board part numbers only differ by one digit. The overdrive and OD-II had a different, much more distorted, fuzzy circuit close to a Big Muff.

Around 1982 until 1985 the Ibanez pedals were repackaged and the 9-series of effects were made. The most popular was the TS-9 tube screamer, which is almost the same as the TS-808 internally. Externally the on/off switch grew to fill about 1/3 of the effect. The main change in the TS-9 circuit is in the output section. This caused the tube screamer to be a bit brighter and less "smooth". The Edge from U2 uses a TS9 for most of his overdrive tones, as do countless other famous rock and blues players. In later years the TS-9s were put together with other op-amp chips, instead of the JRC-4558 which is called for in the schematics. Some of these sound BAD, especially the JRC 2043DD chips. Many used the Toshiba TA75558 which was continued on the reissue. If you have an original TS9 with the 2043 chip, our 808 mods will make a huge difference in tone. 

In about 1993, Ibanez started to make the TS-9 again due to popular demand. This "reissue" is just about identical to the last "original" TS-9s in sound, circuitry, and appearance. They even used the old manual dated 1981 to confuse us more! The IC chip they use in the reissue is the same as some later original TS-9s, the Toshiba TA75558. They are a higher tech chip that will work well in higher tech equipment (where you want a low noise op amp) but are not the best for a tube screamer.

In late 2002 the largest change to the TS9 ever took place. Maxon (actually Nisshin Onpa, the manufacturer or Maxon pedals) is no longer making the TS9 and TS9DX pedals for Ibanez. Ibanez is now having another company make them. The new TS9s are now easy to distinguish. The new circuit board is of slightly cheaper construction, and no longer says MAXON, now it says Ibanez. You will also see IBANEZ cast into the case if you pull back the foam a bit near the battery, the older ones said MAXON there. The battery covers also have IBANEZ on them instead of Maxon. The battery covers had never been changed since the original TS-808. 

You can tell an early TS9 by the green coated resistors inside. But 1980 TS808 that has mostly tan coated resistors and a few green ones so they were not consistent. Some late originals used the brown coated resistors also, so check the date codes on the electrolytic can capacitors.

In late summer of 1998 the TS9DX Turbo Tube Screamer was made available for those who want more volume, distortion, and low end. It is the same as the TS9 but has an added knob which has four MODE positions. Each position adds low end, increases volume, and actually decreases distortion.

Here is something for the pedal geeks like me. (IQ level 9000 required)

Although the circuit design details of the legendary Tube Screamer® overdrive pedal have been extensively analyzed and documented in the past, the key aspect of its design, which is primarily responsible for the signature overdrive sound, has remained unrevealed. This key aspect consists of a subtlety in the clipping circuit employed by the legend.

Operational Amplifier based inverting amplifiers with back-to-back diodes in the negative feedback path are common clipping circuits which are regularly utilized in overdrive and distortion effect designs. When the output voltage exceeds the forward-voltage drop of the diodes (about 0.3 V for germanium diodes and 0.5 V for silicon diodes), the diodes turn on gradually and softly clip the output waveform symmetrically as shown in Figure 2. This is exactly what is expected from this circuit.

However, when the same circuit is modified so that the input voltage is applied to the noninverting input of the operational amplifier (i.e. the circuit is converted to operational amplifier based noninverting amplifier) something strange happens. It turned out that the output waveform of the noninverting clipper consists of two components: (1) the amplified and clipped version of the input waveform.  (2) Plus the unamplified input waveform. That is, the noninverting clipper adds (or mixes) the original input signal to the amplified and clipped input signal. The amplified component is softly clipped at the forward-voltage drop of the diodes, whereas the combined components are clipped hardly at positive and negative supply rails in rail-to-rail operational amplifiers or at a level lower than the positive and negative supply rails in non-rail-to-rail operational amplifiers.

Inserting a 47nF capacitor in series with the resistor R1 forms a pre-clipping first-order high-pass filter with a cutoff frequency of 720.484 Hz (R1= 4.7 KΩ). This filter causes phase shift between the unamplified input waveform and its amplified and clipped version, which results in the output of crooked waveform.

Mixing the input signal with the output signal of the clipper preserves the original dynamics of the input signal which otherwise would get lost at the threshold of clipping. Preserving original dynamics of the input signal avoids muddiness and vastly improves clarity and responsiveness. This subtle feature constitutes the heart of Tube Screamer®’s legendary sound and feel.

Post-clipping equalization circuit contains another subtle detail: the exact cutoff frequency of the first-order high-pass shelving filter is linearly dependent on its gain (i.e. boost/cut gain in dB) parameter (with slightly different slopes for boost and cut segments). This is called progressivity of the parameters and it is an inherent feature of almost all great sounding analogue equalization gear.

The pedal was popularized by Stevie Ray Vaughan. Phish guitarist Trey Anastasio implements two TS9 Tube Screamers in his rig. It is widely used in genres as diverse as country, blues and metal. The Tube Screamer has since spawned many clones and modified versions.

 Possible modifications include use of mismatched, or different diodes (for example, a silicon and a germanium device), or more than two diodes in various arrangements, or modified tone circuits. It is also used by the majority of metal guitarists before the lead channel of the high gain amps to make distortion more focused and to cut the low end. Notable modifiers of the pedal include Robert Keeley of Keeley Electronics and Steve McKinley of Tube Screamer

The Tube Screamer series of distortion/overdrive boxes from Ibanez has a reputation that has led them to pass into musical urban myth. Helped along with Stevie Ray's use of them, the TS 808 and TS 9 have been sought after and traded up to astronomical prices. The other members of the TS family, the TS-10, the TS-5 and the TS-9 reissue have had a more troubled reception.

All the members of the TS family share a common technical design, with the similarities vastly overwhelming the differences. The TS series seems to be at its best when driving the input to a tube amplifier - that is, a triode grid connected to ground through a resistance of about 1M. All the TS series are capable of making their own distortion, but by itself, this distortion is much less interesting that what you get into a tube amp input.

R.I.P. Stephen "Stevie" Ray Vaughan (October 3, 1954 – August 27, 1990)