in 1978 boss released what would go on to be one of the most popular distortion pedals ever created. in fact, the first pedal that was given to me at 10 years old was a boss ds-1. i was, and still am, a massive nirvana fan, so i had to have one. even to my 10-year-old ear, it didn’t sound like the ds-1 kurt had. at the time i didn’t know it, but that difference in sound was a consequence of boss redesigning the circuit in 1994.

from 1978 to 1994, the ds-1 was a single op-amp based circuit. with the redesign in 1994, the circuit would become a dual op-amp based circuit with one op-amp cascading into the other at the gain stage of the circuit. this change, along with altering the tonestack to have less bass and more treble, fundamentally altered the sound of the ds-1.

we are proud to present the yesterday effects b494 - a recreation of the original ds-1 design, before 1994. b494 features the exact, period-correct toshiba transistors and diodes used in original units, along with true bypass wiring, and 9v-18v center negative compatibility.