HUMS HUMS HUMS HUMS AHHHHHHHHHHHHHHHHH I HATE HUMS

Started by milkwasabadchoice, May 15, 2005, 11:38:35 PM

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milkwasabadchoice

OK heres the prob. I am loving my setup and my tone and  I am biginning to build it up and I love it BUT........... it hums like crazy! I am using 3 wallwarts to power the pedals and one of them is split into three parallel plugs. From what I can understand it is a 60 cycle hum and i think its because of how I am powering the pedals. Am I even on the right track? I guess the qustion is what would help more... A good powersupply like the Ultra Clean power supply from general guitar? or like george l cabels? Will it help to build one "clean" power supply for them all?  The wall warts are all plugged into a power strip and I am getting really sick of it.  I can't turn anything up when I play live! Can someone just explain power issues like clean vs. dirty power and mabye ground issues? It would be so much help just to learn a little about it all. How do I elliminate this crazy power hum?

Thanks,
Jason

I'll try to get some pics of my setup up int the next couple of days.

R.G.

This particular set of problems (you almost certainly have more than one) has been flogged to death. Do a search on hum instead of asking us to retype it all. When you've read the search stuff, come back with any questions.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Alex C

Here are a few threads that should help.  A quick search on any topic will usually return a few days' worth of reading material.  Also, read EVERYTHING at GEO before asking a question, because R.G. has already answered it there.  It's an amazing resource, and you'll learn a ton. You should look at the Spyder Power Supply.  Welcome to the forum!

If you're using single coils, they are prone to 60-cycle hum.  If you have a humbucker-equipped guitar, does that produce hum as well?  If your single coil guitar can select the bridge and middle pickup (or two pickups which have opposite polarity), try that and see if it still hums.  

Does the problem only happen when using the wall warts?  Are the wall warts regulated (like the Boss PSU or the one-spot adaptors)?  Unregulated (or poorly filtered) wall warts can be extremely noisy.

Try using the guitar straight into the amp, and see if it hums.  With the least amount of possibilities for the source of the hum, it should be easier
to pinpoint the culprit.  If guitar-->amp sounds okay, try inserting pedals into the chain one at a time, and check for hum each time.  

http://diystompboxes.com/sboxforum/viewtopic.php?t=31391&highlight=hum
http://diystompboxes.com/sboxforum/viewtopic.php?t=30424&highlight=hum
http://diystompboxes.com/sboxforum/viewtopic.php?t=30942&highlight=hum
http://diystompboxes.com/sboxforum/viewtopic.php?t=28836&highlight=hum
http://diystompboxes.com/sboxforum/viewtopic.php?t=28371&highlight=hum
http://diystompboxes.com/sboxforum/viewtopic.php?t=27300&highlight=hum

P.S.  Sorry if I come off as condescending.  I tend to think of the newcomers here as complete beginners, which is often not the case.

niftydog

humbuckers cancel hum, that's why they're called humbuckers... just clarifying... if you have a humbucker equipped guitar that might help you locate the causes of the problem.

causes of 60 cycle hum include;

single coil pickups
poorly filtered power supplys (in both effects and amps)
ground loops (very, very common, most likely a large factor)
flourescent lights
poor shielding in guitars and effects
poor quality cables
poor ground connections (high resistance)
etc etc etc...
niftydog
Shrimp down the pants!!!
“It also sounded something like the movement of furniture, which He
hadn't even created yet, and He was not so pleased.” God (aka Tony Levin)

petemoore

try it with the guitar unplugged...plug a different one in if you get a chance.
 I 'get away' with using a couple wall warts, they're both powering regulators that provide power to the circuits. All the other times I tried wall warts, there is increased hum.
Convention creates following, following creates convention.

milkwasabadchoice

MAN thanks so much for all the info. I was wondering if this had already been addressed. I am using a dual humbuker guitar. This is what I did. I plugged up my guitar to my orange squeezer then with a patch strait to my amp. When I power it with the wallwart it has a ridiculous buzz then I bypass it, and switch to a power jack-to-9v adapter and it is DEAD SILENT when I use a 9v. Sounds amazing! Thants what makes me think its my power.

niftydog

are you sure the wallwart is DC and not AC?
niftydog
Shrimp down the pants!!!
“It also sounded something like the movement of furniture, which He
hadn't even created yet, and He was not so pleased.” God (aka Tony Levin)

milkwasabadchoice

Ya they are AC to DC converters. Can anybody tell me about the "Ultra Clean POwer Supply" from the General Guitar Gadgets site. THis is the one I want to build because I dont want to have to buy tone of transformers plus all the room it takes. THis one looks small and easy. Is this one ok?   [/img]

aron

Yes, I guess I would make a voltage regulated circuit and make sure that the wall wart has enough juice to run everything. From what you said, it should fix your problem. You could also simply pick up a regulated wall wart from your local store.

niftydog

that power supply is fine, but it's by no means guaranteed to fix your problem(s).

In the simple set up your described before (guitar - orange squeezer - amp) have you tried different wall warts to power the squeezer? It may be that one of your supplys has a problem.

Two possibilities;
- the wall wart is causing a ground loop.
OR
- the wall wart has poor filtering and is introducing a 60hz ripple to the signal chain

If it's the later, the ultra clean supply might help.

If it's the former, you need to take more drastic action - like building the Spyder power supply from geofex.
niftydog
Shrimp down the pants!!!
“It also sounded something like the movement of furniture, which He
hadn't even created yet, and He was not so pleased.” God (aka Tony Levin)

milkwasabadchoice

Could you spell out in baby terms what a ground loop is. What path causes it?

Thanks,
Jason

niftydog

yes I could, but I've already done it a bazillion times before... ok maybe that's a bit overestimated... a million times!

Very quickly, any device with more than one connection to ground has the potential for causing a ground loop.

See this thread as one example of many discussions here, and this article for more.
niftydog
Shrimp down the pants!!!
“It also sounded something like the movement of furniture, which He
hadn't even created yet, and He was not so pleased.” God (aka Tony Levin)

RDV

I usually find that if I play without pants on in public the hum magically disappears!

Sha-ZAM!!

RDV