EQ
The EQ section of the pedal is set up a bit differently than many other pedals. The controls are basically like a vintage Fender amp (although the pedal in no way sounds like a Fender). One thing this means is that the controls are interactive in relation to one another. An example would be that turning down the treble will not only cut the higher frequencies, but also raise the lower frequencies a bit. This type of interaction opens up an almost endless palette of tones by adjusting the Lows, Mids, and Highs, as opposed to a simple high pass / low pass setup. It's one of the things that makes the Two Five unique.

Voice Switch
The voice switch allows you to configure the clipping section of the pedal in two different ways:

Voice switch toggled down, there are two Mosfet transistors used as diodes, and a germanium diode as well used to create a super rich, saturated gain (sorta Marshall™ like). Flick the switch up, and two LED’s are used for the clipping. These LED’s have a much wider range of dynamics and lend to a more open, somewhat cleaner sound sort of Fender-like). The Two Five gain will be more crunchy, cutting, and less saturated than the other setting.

Op-Amp
After many hours of testing, A/B’ing, and comparing, the designers finally settled upon a JRC3404. A distant relative of the famous JRC4558 some covet for their use in vintage Tube Screamer pedals, this op-amp is tough enough to put up with 25V, but still has a warm enough tone to keep things nice a sweet.

Output
There is a ton of output on tap. Be careful with this! You can peg the front end of your amp incredibly hard which is great for pushing it into a natural overdrive.