The overdrive par excellence. Similar to the original circuitry and based on the 4558 IC chip, the TONE SCREAMER offers the smooth, natural overdrive sound of a full-opened tube amp in a compact pedal. Incredibly dynamic and accurate, the TS 4558 responds to the nuances played and allows you to hear the natural sound of your instrument. This fine and pleasant distortion is genuine to the overdriven sound of tube amplifiers. A blended waveform, with little signal loss, will produce a full blues sound. The pedal can also be operated on a transistor amplifier to control the sound of a vintage tube amp, or to use a guitar amp to amplify a tube amp. The TS 4548 Sound Screamer Sound includes a "mid hump" that accentuates the frequencies between the bass and treble (mid frequencies). The main component of the EXCALIBUR TONE SCEAMER is the Op-Amp. This makes the flavour of the distortion. We're convinced, the 4558 chips is the best. Only this 4558 is used in the EXCALIBUR TS-4558.

Just google for sound clips, I know several people who sold their 808 and ts9 for this.