How many different dirt circuits? What layouts? Exactly the same amount of noise, or varying amounts but noticeably bad?
Any noise from the power supply will be massively amplified by high gain levels within fuzz/overdrive/distortion pedals, so is much more noticeable than with modulation fx that tend to just buffer the signal at unity gain, and then maybe split it in two and modulate one of those two signals before recombining them at unity level (e.g chorus+phase) or just modulate the straight buffered signal (e.g many tremolo circuits). If your diy dirt pedals are much worse than commercial equivalents, with the usual cap + resistor (i.e. 100r or so resistor from +9v leading to a 100uF or so electrolytic cap to ground, with the 9v to the circuit coming from the top of the cap.
If the noise is still bad with decent filtering, and the DC adaptor is known to be good and noise is not blighting other dirt pedals, it is possible the layout or wiring of a DIY build is contributing to the noise: This would obviously not affect different pedals in the same way, but it is easy to check wiring by opening the pedal and moving the input and output wire around a bit - If the input is running near the output or some certain part of the board, it may amplify noise but the noise will change as you wiggle the wires. Layout noise is hard to pinpoint, but rare and would also not affect several pedals in the same way unless they are all clones built with identical layouts.
I have used a +9v regulator with a a 9.2v supply, and it worked but I'm not suere it made any difference to the noise floor, plus they usually need a 12v supply to be totally reliable. TO-92 regulators are just like transistors, but one pin is for "in", one to ground, and one to "regulated out": They are usually filtered with a cap to gound on the in and out pins, with a higher cap on the in.
mmolteratx wrote:absolutely zero commercial use allowed. If I find anyone selling these, I'll fly to your house and kick you in the nads. And you may or may not find yourself in trouble.