Another grounding question for multi-effects

[studiostud]

Hey everyone,

I've done a number of builds in the past so I'm pretty familiar with individual pedal building.  Recently, I've taken on a project of putting multiple circuits in one box and the offboard wiring is starting to get confusing to me.  I basically have a bunch of individual pedals in one box meaning each circuit has an input and output jack and a 3PDT stomp switch w/ LED.  I put all the I/O jacks on the back of the enclosure like a patchbay so I could wire them in different orders if desired.  The main input stage has the main input jack going to an A/B switching 3PDT with two output jacks that are used for a Tuner and the output to the "patchbay".  It also has a main output stage that has an input jack (so I wouldn't have to tie the main output jack to a specific circuit) that goes to a DPDT toggle that switches between the main output jack and a headphone amp circuit that outputs to a stereo 1/8" jack.  To power everything, I installed an Adjustable Power Supply circuit from Tonepad and wired it to a power jack.  Then, instead of using a transformer before the circuit, I just used a 12.6V wallwart adapter which seems to work fine.  So my question is this... how should I PROPERLY ground this thing?  I have 2 of the 5 power outputs powering half the pedals each and a third output powering all the indicator LEDs.  Right now I have each circuit's GND out going to it's respective output jack sleeve which is connected on one of the 3PDT lugs to the input jack sleeve.  Then each of the (TRS) input jack rings are wired in parallel on a "daisy chain" that goes to the ground lug of the Power Supply output that powers that section of circuits. 

If this sounds like a lot of wiring, it is!  Technically, everything works.  I can run cables to the I/Os of each pedal to my amp and guitar as well as I can hookup everything with TS patch cables and everything works.  The reason I'm here asking about this is because I get a fairly decent amount of noise, specifically from the high gain distortion circuits. For the distortion circuits, I have a Fuzz Face, Tube Screamer, Big Muff Pi, and a Rat.  The Fuzz Face has some hum, especially when volume and/or fuzz pots are up past about 7/8 and when using the Fuzz Face with another distortion, the hum is amplified.  One interesting thing is that the Big Muff and Tube Screamer don't have a huge amount of noise together, but either of them with the Fuzz Face or the Rat gives me unusable results.  As far as the Fuzz Face, I've searched all over this forum and tried several different ideas for getting rid of the hum and haven't been successful.  It is from the Tonepad layout and is wired with a neg ground. 

So my question comes back to ground.  From what I described above, did I do everything right?  Essentially, I just followed the same 3PDT offboard wiring diagram (http://www.grassrootsaudio.com/pics/stompboxwiring.gif) for each circuit and then connected all of the Input rings to a common ground on the power outputs.  What else could I do differently to get the noise down on the high gain circuits.  Could I take each board GND out and secure it right to the metal chassis instead of going to the output sleeve?

I apologize for this being long winded.  I just wanted to give as much detailed information as I could to help in the troubleshooting.  Thanks in advance for any input!


Jeff