The Synapse Vintage EQ-3 is a precise model of a 3-band analog tone stack, as found in late 50s guitar amplifiers. The unique sound of these devices is due to the coupled, passive circuits employed, where changing any parameter affects the entire network in a complex way. This is different from a digital parametric EQ, which operates on just one isolated region of interest. While this comes at the advantage of precise boost and cut amounts (useful in correcting a mix), the overall sound is often too predictable and boring. For creative sound shaping, the Vintage EQ-3 is often a better choice.
In addition to the low, mid and high band parameters found in the vintage tone stack, the Vintage EQ-3 adds an Offset parameter, allowing to shift the entire frequency-response an octave up or down.