Fatpants hum?

[hoyager]

Hey, does anyone else have a hum with their fatpants?

I've built v1 and v2 both with the same hum, but I am using s/h random 9v adaptors. I've minimized it using one of these

http://www.beavisaudio.com/projects/Huminator/index.htm

Anyone else with the hum?

Andy

[jkokura]

Nope, mine is really quiet.

Jacob

[dwstanford]

yeah, mine's really quiet also.  try running it with a 9v battery and see if it goes away.  if so, it's some sort of power issue somewhere.  if not, im not sure.  maybe a microphonic cap or something.  is it a high or low pitched hum?  are you running it by itself or with other pedals?

[gtr2]

hmm...mines quiet as well

Josh

[sgmezei]

I only had trouble with mine with a high pitched whining. Was the charge pump.

[bigmufffuzzwizz]

I've only tested mine out of a box using my test rig and it's quiet as can be.
If your using the charge pump chips that have CPA at the end of the parts number, those have been reported many times to create noise mainly a high pitched squeal. If that's what you have you wanna find the SCPA version.
If it's hum might be time to pull out your audio probe. See if the signal hums going into the circuit or if it starts somewhere in the circuit. If its boxed up, it could be ground related ie. bad ground connection.

[hoyager]

Hmm.. its def coming from the circuit, its by itself but its not boxed up though. Its a 50hz hum, NZ.. The hum eliminator is totally working for now at least. I've used a 1054 CN8 charge pump

[JeffdaMaori]

I would consider looking at the charge pump chip.
The 1054 I believe is different as the MAX 1044. For the MAX 1044 pins 1 and 8 need to be connected as per layout. For the 1054 pins 1 and 8 shouldn't be connected to work properly.
Someone correct me if I'm wrong here.
Maybe you try putting the 1054 in an extra socket on which you've removed pin 1 (in socket) and plug it ('piggyback' it) into the socket on pcb and see what happens.
Or try a different charge pump, I've used successfully a MAX 1044 and a 7660SCPA, no hum or the like.
Hope that helps.

[G.G.]

Hey Scott,
How did you end up fixing the charge pump? Swap out a different IC?  Finally got mine going but I noticed it does have a slight high-pitched whine.

I only had trouble with mine with a high pitched whining. Was the charge pump.

[sgmezei]

yes I did swap it out. After going over the pedal for a few hours!! hahaha

I have found that one brand, I think Maxim, I will have to double check, always gives out a whine the other ones I have don't.

[hoyager]

Maxim 1044 shouldn't whine. LT1054 will if pin 1 isn't bent up before going in the socket.

[jkokura]

Max1044 will if it's a 1044cpa. Using an 1044scpa is usually the way to make the whine disappear.

Jacob