Early American tones…Tweed – Plexi – Blonde – Brownface…not just the sound but the feel as well. SY1 is brighter with more headroom and is especially good into a British-voiced amp/speaker…great for pushing a British amp into overdrive and distortion, or capable of making the distortion itself into a clean amp. The SY2 is voiced more for running into American amps/speakers…not as bright and a little more compression. They are also voiced to be used into each other…SY1 into SY2 covers a huge amount of ground. Volume and Drive controls are standard. The M and T controls are a very versatile EQ section that can also be used as an EQ with the drive down. The M control is for low mids and helps cover the various cabinets and speakers you find from Deluxes up through Showman and Bassman configurations. And the M controls pre-distortion so it also affects the saturation of the drive and will push past the vintage tones into blooming distortion and even fuzz like tones. And finally, the post-distortion Treble control is there to get the sound just right.