Hum - what's wrong with my gear?

[Victor Gwee]

Hello all,

I'm new here, a friend recommended me to this website. I'm a student, and I own 3 guitars (1 acoustic, 1 electric, 1 acoustic-electric).

My problem is that hum is audible when I'm playing. Usually, when I'm playing at home, the noise is not audible to others. But if I put my ear to the speaker, it's audible. I've heard that a tiny bit of hum nullifies good tone.

My amp is Custom 30 Watt, bought from Davis Guitar. Of the two guitars that can be plugged into an amp, the electric is entry level (MII "Artisan" Brand Strat copy , no series no., $125) and the acoustic electric is Washburn WD10SCE, original price $330. Cables are "no-brand" cables, one says "Marukawa Video/Audio OFEC Cable Japan". I only have one effect pedal (for now) which is the DOD Milkbox (compressor) running on batteries.

I can experiment with several different setups for hums. With gain/level/EQ/Volume/compression all cranked up and "Artisan" Electric,

1. nothing plugged into the amp : sounds like sand flowing.
2. cable into the amp (other end of cable free) : hum is loud and bassier (50Hz).
3. with guitar : hum is like no.1, plus a high frequency whine.
4. with compressor(off) only: like no.1
5. with compressor (on) : like no.1
6. with guitar+compressor (off): like no.3
7. with guitar+compressor (on): no.3, hum super loud.

Could help anyone identify the problem (or problems) and propose affordable solutions? Affordable would be about $100, max 150. DIY possible if necessary. Thanks

My theories:
1. Amp operates with switchmode power supply, so hum is higher frequency than 50 Hz.
2. Cable head, when not plugged in, picks up 50Hz.
3. Guitar is not shielded well, picks up RF Signals?

 

[PatheinRaindropMoe]

1. nothing plugged into the amp : sounds like sand flowing - This is normal, same like pushing up the volume of any system with volume control

2. cable into the amp (other end of cable free) : hum is loud and bassier (50Hz). - Again, this is normal, the other end of the cable with the plug not connected to anything, is acting as an antenna, picking up any stray frequency in the air around us. Plus, the ground connection is "floating"

3. with guitar : hum is like no.1, plus a high frequency whine. Is your guitar equipped with single coil pickup? If it is, then hum is normal(unless using specific after market single coil pickup that is hum/noise free).
If its with humbucker, hum or high freq squealing should not occured. Possible cause of it could be from microscopic pickup, guitar cavity shielding issues to wiring issues etc.

4. with compressor(off) only: like no.1
5. with compressor (on) : like no.1
6. with guitar+compressor (off): like no.3
7. with guitar+compressor (on): no.3, hum super loud.

For point 4 ro 7, it doesnt matter what effect is on or off. If the hum/noise arises from the guitar itself, any form of effect, be it compressor, boost, overdrive, distortion etc, will still result in having the noise/hum issues. Worst still, if you are cranking the setting from the effect pedals. It will further amplified the effect of the noise/hum.

Anyway, you can forgo the testing with the cable plugged in to amp at one end, with the other end free. No one will do that coz by doing that, other than the metal plug acting as antenna, the most obvious reason not to do so is that you have a floating ground issues, which anyone doing wiring stuff, will avoid. It will result in the loud hum you hear. Ground path supposed to be grounded and not floating, thus the term floating ground.

Before sending the guitar for check, you can start by checking if your amp is using a 2 pin or 3 pins adaptor. If its 2 pins, do change it to 3 pins, for the ground connection.

If amp has 3 pins adaptor liao, then shift to guitar cable, try another cable and see if the noise/hum issues still there.

If cable change liao, then check the guitar. If its single coil geetar, then yes, hum is one of the colour of such pickup. If pickup is fine, then check shielding of the wiring cavity, wiring of the pickup etc, replace the pots etc.

If all done liao, still got those issues, but less, then try this, go outside of the bedroom scenario and start playing in a band jamming setting, some of this noise/hum issues, will "disappear" by itself. Due to being in a band jamming setting, such noise/hum problem will be of secondary concern unless cranking all that you can. Cranking parameters on amp/effect pedals, effect will result in noise, learn to reduce gain and up the volume or increase gain and down volume. One increase, the other decrease.

 

[Victor Gwee]

Thanks Wonderful explanation.

My amp is grounded, my guitar is strat-style so yes single coil. But if I select two pickups it becomes like a humbucker is it? Louder, fatter tone, higher mids. But whether I select one or two pickups it doesn't make a difference in hum here, strangely.

On a side note, is it a good investment to use better cables? If so, what brand of cables would you recommend?

 

[Jumpin'Jellybean]

Yup better cables.
Everything contributes to good tone.
Good starting point would be Planetwaves

 

[PatheinRaindropMoe]

for the dual single coil setting you mentioned, it's usually with the config of the middle single coil + bridge single coil or middle single coil with neck single coil.

With this config, also know as the 2nd and 4th position on the 5 way selector switch, inorder to be hum cancelling, the middle single coil pickup should be reverse wound/reverse polarity(rw/rp the term usually used online to indicate this) in respect to either the bridge or neck pickup.

Am not too sure how is the wiring for your geetar, imho, if you dont want to tinkle too much within, can send to guitar tech to check out the wiring and see what they suggest for your situation. Most prolly it would be rewiring, cavity shielding etc. For cost and recommendation, wait for a while for other bros to recommend.

For cable, better is subjective as that would depends on the usage and purposes etc. In general, anything for guitar related, the whole signal chain matters, from cables to plugs to guitar to effect. All of it will work towards a satisfying result for the end user.

If theres any issue along the signal chain, the best way to solve the problem, is to find out the cause of it and work from there onwards.

Recommendation, hehe, as usual, will leave it to rest of the bro bros.

 

[cheesedaele]

Am I dreaming? Such a well-researched request for help, and such comprehensive and informative replies? On reading the first post I was going to reply with something useful, but after scrolling down PatheinRaindropMoe seems to have already covered everything. Very well too.

Threads like these make me feel warm and fuzzy.

==

Yea use a decent cable, I'd go with Planetwaves to start too: reasonably priced, good shielding, moulded ends for durability.

 

[an2]

Cable Recommendation? Canare user here through and through. Go look @ TY Music Center to see what suits you

 

[VidaK]

Am I dreaming? Such a well-researched request for help, and such comprehensive and informative replies? On reading the first post I was going to reply with something useful, but after scrolling down PatheinRaindropMoe seems to have already covered everything. Very well too.

Threads like these make me feel warm and fuzzy.

==

Yea use a decent cable, I'd go with Planetwaves to start too: reasonably priced, good shielding, moulded ends for durability.

totally agree with you, up for PatheinRaindropMoe =)

 

[subversion]

I've heard that a tiny bit of hum nullifies good tone.

3. Guitar is not shielded well, picks up RF Signals?

hi my friend

. since the technicalities have been covered, my additions here are anecdotal...

single coil lovers are living with malignant hum all along & it's no tiny bit- it's major lucidity-consuming hum. it's a trade off, we love the single coil snap but can't help but hear the hum when distortion is engaged. we can't get rid of it, just shut it off between play.

my rig did pickup RF signals once but it's no humming; i heard people conversing in Japanese. i have no idea if this was attributable to the Japanese guitars i played. but it turned out to be poorly shielded cables, didn't get to check if they were made in Japan though, brought them to the office & somehow misplaced them thereafter.

 

[cheesedaele]

my rig did pickup RF signals once but it's no humming; i heard people conversing in Japanese. i have no idea if this was attributable to the Japanese guitars i played. but it turned out to be poorly shielded cables, didn't get to check if they were made in Japan though

LOL cracked me up. That'll teach me to surf soft while working.

 

[subversion]

you're working at this time of the day/ night?

 

[zesn]

Wonders if noiseless single coils loses mojo =3

 

[grin.guitar]

For cables, I'd suggest mogami from Tymc. I used to use planet waves, but had a friend who used mogami so decided to get one to try out myself. I A/Bed the 2 side by side. Both had roughly the same length. The tone with the mogami (with amphenol plugs) was noticeably clearer.

I'd think canare that was mentioned earlier would be comparable.

 

[cheesedaele]

you're working at this time of the day/ night?

Was working a gig. Bursting out laughing when you're supposed to remain invisible = bad.

 

[Victor Gwee]

Hmm ok, I think I'll either try the Planetwaves cables or get a custom one from either TYMC or Luther Music.

When I opened up my strat, it had some foil shielding on the pickguard. But it's only on the pickguard, not 360 degrees, so i guess it's not sufficient.

Found this link on shielding a strat, useful? http://www.guitarnuts.com/wiring/shielding/shield3.php

 

[PatheinRaindropMoe]

you found the right site for shielding info. Anyone searching for guitar shielding online will sure come across the page.

If you cant find the copper tape mentioned for job, but wanna diy, you can substitute with aluminum foil(but non stickable) or air con duct tape(silver in colour, stickable, able to connect electrically and easyto get from hardware store like homefix for couple of dollars)

And if using the cheapo method with the aircon tape, you will need to improvise, to connect the cavity ground wire to the tape, either through washer method and then paste the tape over it while testing continuity with a multi meter after that to ensure the connection/contact is electrically connected(if not, it will defeat the purpose of shielding)

As you have noticed, beneath the pickup, theres a layer of foil underneath. If you do shield the cavity, you will need to have the foil underneath the pickguard to be in contact with body cavity shielding so that the whole thing formed a closed environment in order for the purpose of shielding.

If you are interested to find out more on the science behind shielding, can search for faraday cage/guitar shielding. The idea of guitar shielding prolly wont be around if without Michael Faraday