volume pot hum?

slash1953

Hi,
ive a problem with my guitar(s) re volume pot? When its at zero the amp is quiet but as you get to about midway a hum builds up and drops of as it the pot is turned full on?
Ive fitted new pots etc etc but still its there.

Modulus_Amps

Sounds like your guitar is picking up something in the room and amplifying it

Does it reduce if you move /angle away from the amp
have you tried the amp/guitar in another room?
Plugged the amp straight into the wall, no extension leads
tried the setup with no effects boards and no effects power adapters plugged into the same line as the amp
turn off the lights/computer etc

ICBM

What type of guitar?

It's fairly normal, although it does vary depending on how well shielded the jack and control cavity are.

Keefy

I get this on my Strat, but I've only ever noticed it at home, never been a problem on a gig.

slash1953

Modulus_Amps said:

Sounds like your guitar is picking up something in the room and amplifying it

Does it reduce if you move /angle away from the amp
have you tried the amp/guitar in another room?
Plugged the amp straight into the wall, no extension leads
tried the setup with no effects boards and no effects power adapters plugged into the same line as the amp
turn off the lights/computer etc

its a les paul and the hum is really loud onstage.Im going to try again tomorrow when house is empty and crank it and see what it does?
Ill be back with result?

ICBM

slash1953 said:

its a les paul and the hum is really loud onstage

Sounds like the shield connection to the cable that runs up to the switch might have broken, so that 2-3 feet of wire is now unshielded.

Modulus_Amps

slash1953 said:

Modulus_Amps said:

Sounds like your guitar is picking up something in the room and amplifying it

Does it reduce if you move /angle away from the amp
have you tried the amp/guitar in another room?
Plugged the amp straight into the wall, no extension leads
tried the setup with no effects boards and no effects power adapters plugged into the same line as the amp
turn off the lights/computer etc

its a les paul and the hum is really loud onstage.Im going to try again tomorrow when house is empty and crank it and see what it does?
Ill be back with result?

I have pulled a few of my amps apart trying to track down hum that reacted just the same, only to realize days later that it was a bad extension cable, bad guitar cable or bad pedal power supply. point being eliminate everything external first.
Trying the guitar with another amp would help too if you can.

slash1953

update: my board is hard wired,I plug into  wha, ts  808,tuner and out to the amp. the hum stops when I plug directly into the last pedal in the train (tuner).It seems as if its the last 3" of cable from the tuner to the jack socket causing it? Im kinda thinking that the power wires coming from the Gigrig distributer may have something to do with it as they pass over the lead and the are unshielded? It does sound like a DC hum? Im thinking of ditching the distributer and going to daisy chain? Wasting my money?

ICBM

Sounds like the patch cable in front of the tuner might be faulty. If not then it could be another ground connection on the board between the input of the tuner and the input of the TS, if plugging into the TS still hums.

There is no such thing as a 'DC hum' - by definition DC does not cause hum because it's 0Hz. You don't need to separate DC and signal cables for that reason - assuming the power supply is decent quality and isn't actually leaving a ripple on the DC.

slash1953

Its not the cable its the tuner!!!

ICBM

slash1953 said:

Its not the cable its the tuner!!!

What type of tuner? If it's a Boss, check that the jack nuts are tight. They can work loose and sometimes make a poor ground connection. You can tighten them without taking the pedal apart - they're a square box inside and can't turn round.

slash1953

ICBM said:

slash1953 said:

Its not the cable its the tuner!!!

What type of tuner? If it's a Boss, check that the jack nuts are tight. They can work loose and sometimes make a poor ground connection. You can tighten them without taking the pedal apart - they're a square box inside and can't turn round.

its a polytune,im borrowing another to try....

ICBM

slash1953 said:

its a polytune,im borrowing another to try....

Also try it at the start of the chain instead, if plugging into it directly doesn't hum. It's true bypass so it won't affect the wah.

slash1953

ICBM said:

slash1953 said:

its a polytune,im borrowing another to try....

Also try it at the start of the chain instead, if plugging into it directly doesn't hum. It's true bypass so it won't affect the wah.

yeh,its hums being plugged directly.

Keefy

Check each patch cable for earth continuity. Then check each pedal on its own in turn; then each pair of pedals. Process of elimination.

slash1953

well,it looks like Ive cracked it? It must have been the unshielded jack last in the chain? Ive replaced with a barrell type jack and the hum has gone. Theres always been a slight buzz,nothing big but was just wondering if I should change the power plant for an isolated one? Thanks al,for your suggestions,its appreciated.

Keefy

Some pedals (eg Line 6) are well known for not playing nicely with other pedals on the same DC supply. If your current power supply isn't giving you problems then there is no real reason to change to an isolated one.