Formula B "That Screamer"

The THAT SCREAMER 4558 is built from the analysis of three original pedals from the Formula B collection: an early‑’80s TS808, a 1982 TS9, and a 1986 TS10. Three eras, three distinct voices, studied on the bench and faithfully recreated to capture the authenticity and musicality of the classic units.

Inside the Box: Four Voices to Choose From

The pedal offers four tonal characters, derived directly from the three original models plus a custom hybrid mode. The internal dipswitch lets you select between T808, T9, T10, and a T808+T10 blend that combines warmth and dynamics. The switch is accessible by removing the four rear screws. The factory setting is T808.

Tone and Feel

The TS4558 delivers a creamy, dynamic, touch‑sensitive overdrive that moves effortlessly from light breakup to a more pronounced midrange push. It preserves the natural character of your guitar and responds musically to picking dynamics and volume changes, blending vintage soul with modern reliability. The four selectable modes let you explore the roundness of the T808, the openness of the T9, the tighter and more modern response of the T10, and a hybrid voice that merges warmth and clarity into a unique fourth character.

Circuit and Components

At the heart of the pedal is the original JRC4558D op‑amp from Japan Radio Company, paired with carefully selected tantalum capacitors in the tone section. The circuit delivers 5 dB more output than modern reissues and features true bypass switching.

Controls

DRIVE adjusts the gain. TONE brightens or darkens the sound. LEVEL sets the output volume.