One of the Portland, Oregon-based company's most popular pedals, the Dirty Little Secret is now in its third incarnation and delivers Marshall-like tone, whatever amp you're using.
An internal switch sets the pedal to either Super Lead or Super Bass mode: the first, based on a later 'plexi' model having more gain and a different tonestack with more upper mids; the second more akin to early Marshalls or the Bassman it was based on, with less prominent midrange and lower gain.
Internally, a presence pot dials in the top end to suit your rig. The tone knobs offer the sort of organic control you'dget with an amp and both modes sound excellent, providing a range of drive with familiar British tonal signature.
The Super Lead mode offers enough gain to take you into JCM territory, while the Super Bass takes a fuzz pedal really well for some classic 60s rock sounds.