hi @matttornado , @Gene Ballzz makes good points. Design M (see page 1 summary) is the most versatile because it does every 3.5db step and can run 4, 8, or 16 cabs in the 8 ohm version. But Gene's is the simplest and easiest to build and to use, if you don't need that first -3.5db stage on its own. Also, its absolutely essential to be able to follow the wiring and relate it to the schematic of whatever you build and, if the whole box starts with -7db always on, then there's nothing that can accidentally happen in use to the switches downstream that can hurt anything. The toggle switches needed typically have 6 lugs and are in fact two switches side by side. The centre lugs connect to the upper or the lower lugs. To do the simpler version, you only need one side of the switches but you can link the two sides together with three wire links to double it up to get more current rating and reliability if you wish. Such switches may be called on-on or on-off, but if its six lugs and two positions it would be right. Don't need switched jacks (I use one for the red-box section of my circuit though). Just basic mono jacks are fine for, but for the ones I bought I found the stereo version to grip the plug better. ps... this thread has now had over 30,000 views, with more than 150 in the last 12 hours!