Eliminating hum from new pedal? Suggestions?

[thesameage]

This is probably an easy one for most of you. Any suggestions on how to cut hum from this guy?:
http://www.madbeanpedals.com/forum/index.php?topic=20382.0

Finally tested it out at band practice last night and I get a pretty audible hum when everything is off. What should I do? I think that the culprit might be the power cable runs. The power jack is on the back and does a long run to the mini-compressor, and then there's another long run back to the back of the bass klon. Can I just connect everything to the jack? Or do I have to chain it like that? Here's a pic of the insides. Thanks in advance for any suggestions:

[DuctTapeRiot]

Well I cant guarantee that any of this will for sure cure you problem, but here is my thoughts:

- No you definitely dont need to chain from the compressor footswitch to the bass klon for power and ground.  Remove that, and run power and ground for the klon from the DC jack.
- Dont let your power cable runs lie over components on the PCBs like you have.  Twist them up so they stay together, and run them right down the 90 degree angle where the top meets the sides.
- Make 100% sure your enclosure is grounded.  Looks like a powder coated enclosure, you may want to scrape/sand away some of the coating on the inside of the enclosure to make 100% sure the metal of the jacks are making good contact with the metal of the enclosure. This essentially turns the enclosure into a faraday cage.
- Star grounding is a must (no ground loops).  I can see that you have run ground wires to both your in and out jacks. If those jacks are actually making ground with the enclosure (see above) you have a ground loop.  Each of the jacks is wired to ground, as well as connected to each other through the enclosure.  I generally never run a ground wire to the output jack, and I use the ground on the input jack as the "star" point, as in everything else ground there to ensure no loops.
- Move your LED wiring away from any of the audio wiring.  All the in/out and send/return wiring for each of the pcbs and the bypassed audio signal are going right over top of your indicator LEDs, which can definitely cause noise.  The exposed LED legs scare me, but that could just be me.

Another suggestion would be to use some shielded wire at least for the bypassed part of your audio path (so in jack to switch, one switch to the next, and switch to out jack).

Hope something there helps.  Having just written all that I realized i forgot a very obvious question, are you sure the noise is not coming from your room or power?  Like if you take the pedal out of the chain completely you have no noise?

[thesameage]

All very good points. I'll investigate tonight. THanks for taking the time!

I did try to plug the supply into two different sources last night and still got the hum.

[DuctTapeRiot]

I did try to plug the supply into two different sources last night and still got the hum.

But do you still get hum with the pedal not in the chain at all? The reason I am asking on that one, is I have had a few people recently thinking it is their pedals causing hum, but it turned out to be the power in the room they were in (the wall sockets), in which case no amount of work on the pedal itself is going to help.

[thesameage]

Def the pedal. I ended up just playing straight into the amp after and there was no hum.

[DuctTapeRiot]

Ok, well believe it or not that is a good thing as we know where the issue lies.  Does the pitch of the hum change at all when you fiddle with the knobs?? 

And again just to confirm, you get the hum even when both effects are bypassed??

[thesameage]

Fiddling with the knobs does not change the hum and when the effects are bypassed you still get the same hum. Def tried those variables while I was in the space.

To confirm from above, can I run 2 wires from each power jack prong, 1 to each effect to cut down on wire length? Do I need to put a resistor in there?

[DuctTapeRiot]

Yes that's correct, just strip 2 bits of wire and twist them together and solder both to the DC jack prong.  But the fact that you are getting the hum even when both pedals are bypassed is important at least in my mind. It means that power to the effect boards themselves is unlikely to be the problem. I am thinking that your grounding scheme is most likely the issue, both in terms of having a ground loop as I mentioned, and that the enclosure itself may not be grounded out.  I would reflow all your connections on your jacks, and as best as possible on the 3pdt switch PCBs (just the wiring connections, not the switch lugs which look ok).

Ohh, actually, there is another thought, are you using good quality 3PDT??

[thesameage]

All good thoughts and I think that you are probably correct on all counts... I can't do it tonight (going out to see music), but I'll go through your whole checklist tomorrow night.

The switches are brand new basic ones from http://bitcheslovemyswitches.com/. I don't think that they are the issue.

Thanks again!

[thesameage]

All buzz is gone. Thanks again!

I edited the power wiring by wiring everything from the jack rather than chaining them, I sanded around the in/out jacks for better contact, cleaned up the LED wiring, and rerouted cables so that nothing goes over the PCB's.

Not sure that I'm loving the Engineer's thumb on bass. It really seems to squash the signal a lot and stops the "bloom" of my muff pedal. That's good and bad... still assessing!

[jimilee]

Is it after the muff?


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[thesameage]

I have it before the bass behemoth and it def cuts some of the fuzz/breaking up there. I also ran it before my rullywow pharaoh clone and it focused the fuzz but seemed to cut a lot of bloom of the fuzz around it. Maybe it's just what happens when you have a 1 knob comp. 

[jimilee]

I have it before the bass behemoth and it def cuts some of the fuzz/breaking up there. I also ran it before my rullywow pharaoh clone and it focused the fuzz but seemed to cut a lot of bloom of the fuzz around it. Maybe it's just what happens when you have a 1 knob comp.

Yeah, there's that. My all time favorite is still the ehx soul preacher. I haven't built in yet that I like better, and I've built damn near all of them.


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[thesameage]

I've seen you write that you love the preacher before as well. What do you like about it specifically?

I've used comps in the past, but not so much with fuzzes. So I'm still figuring it out. I have an afterlife on the bench that I need to test as well.

[jimilee]

I hate to use the word transparent, but it doesn't color or change the sound at all. It's the sort of pedal that you don't really know it's there until you turn it off. I have various playing styles and basses, and it doesn't over compress on any of them. You can change the compression ratio of course, but with several compressors, the harder you play, in my experience, they ten to compress more rather than just limit the volume.  I like the knee switch as well, it has 3 different settings and none of the releases are audibly noticeable. I caught one on here for 25.00, what a deal it was.