Post by yetanotherchris on Jun 10, 2007 4:24:36 GMT -5
Hi folks, my first visit to this forum! Apologies if my problem has already been dealt with elsewhere but I couldn't find anything in the subject headings...
I'm working on a project guitar, an Aria Pro II that got trashed in shipping, using 3 Lace Alumitone pickups with strat style switching and an push-pull pot to turn the bridge pickup on regardless of switch position. I've used this diagram from guitarelectronics.com:
My problem is that every time I touch anything metal on the circuit, including the strings, there's an electronic pop which is clearly audible through the amp. There is also an audible background hum.
I've tried replacing the jack altogether and wiring the tone pot differently. If I wire the pot as it is in the diagram above, the guitar becomes full on microphonic, tapping on a component having a similar effect to tapping a microphone.
I've also tried reversing the wires on the jack, which lead to perfect sound when I was touching metal parts but the most god awful buzzing when I wasn't. This is as close I have got to it 'working'.
I don't have the first idea how to connect up sheilding and conductive paint so this might be part of the issue, but the fact that these pickups should be noiseless anyway makes me think there is something fundamentally wrong with my wiring or one of the components.
If it is the cap, as hinted at by the troubleshooting guide on guitarnuts, would removing the tone pot altogether fix the issue?
I think you've got an earthing problem. The diagram you've shown doesn't show any earth connection for the middle tone pot case. AFAIK all pot casings should be earthed. Generally speaking all earth connections should then go back to to the vol pot casing
Post by yetanotherchris on Jun 11, 2007 9:31:33 GMT -5
Ok, so I removed the tone pot altogether in an effort to fix this. I've also put in a different jack. Same thing.
Then I tried something odd last night; disconnected the whole circuit from the guitar and tested it on the kitchen counter. No noises. Worked as it should. So I replaced the old bridge/ground wire with a new one, thinking that was the problem, but it's still popping when I touch the pot, switch, stings etc...
So, it must be (of all things) the bridge/tremolo/sheilding to which the ground wire is connected. Does this mean it's all just an issue of sheilding?
Post by yetanotherchris on Jun 12, 2007 2:24:23 GMT -5
The popping did go away when I wired up the jack the 'wrong' way around, but it was replaced by a full on buzzing of death when I wasn't touching the strings/anything else metal.
Another observation; it seems the noise is worst when I touch the switch. Is this coincidence or is it a possible source of the problem? I'll admit I bought a really crappy switch from a bit of a dodgy source.
Post by michaelcbell on Jun 12, 2007 6:24:06 GMT -5
My guess is that wired 'backward' is actually correct. Yes, with all the noise it seems wrong, but I feel there is another problem. My reasoning stems from the fact that when wired 'wrongly', the noise goes away when touching the strings - which is proper behavior for a well wired guitar. Now, why does it buzz like a killer bee's momma? I'd say make sure all your parts are grounded (using a multimeter is you have one) as suggested by reeced. You might ::cough:: should ::cough:: also want to do the quiet the beast mod as is often discussed on this forum, but let's see if there's another problem first.
BTW, it doesn't seem you've been properly welcomed, so... WELCOME! I'm sorry we(I) here at guitarnuts have been so lax - we're usually better about that kind of thing.
Post by yetanotherchris on Jun 12, 2007 8:35:51 GMT -5
"You said that the circuit worked fine outside of the guitar, yet problems occur when it's mounted. I'm wondering, have you grounded the switch body in the guitar ?"
When you say grounded, you mean 'it's touching the conductive paint in the cavity and that's making something go wacky?' It might be, but I don't think so, the only connections on the switch are those between the pups and the vol pot. <i>Should</i> there be some kind of grounding wire on the switch (I've never seen a reference to one!)?
michaelcbell: I was wondering about that whole jack thing, as I've read something similar to what you said.
The thing is that there is a slight buzzing when wired as it is, in addition to the popping(/squeaking when touchin the switch). When wired the other way there is only a buzzing, but it's a major buzzing.
Please excuse my total ignorance here, I'm really just a monkey with a soldering iron and an ebay account! Everything I know I read online.
Post by michaelcbell on Jun 12, 2007 10:17:50 GMT -5
obviously you have something touching or not touching that just isn't right.
My thoughts - if the buzzing noise gets softer when you touch the strings, that means your strings are connected to the ground (sleeve) on your jack - so in "wrong" mode, your strings are properly grounded. This would also explain the popping when you touch metal in "normal" mode, since the metal parts connect to ground in "wrong" mode, they connect to hot in "normal" mode, which ends up giving you a sound not unlike touching the tip of a cord that isn't plugged into your guitar yet.
Why the huge buzzing noise, then?
Hmm... could you take some pics? That would help.
Does the guitar work all the time? (both "modes", when touching or not touching the strings) What changes when you touch the stings in terms of guitar output, especially guitar level and noise level? (ignore the pop)
Post by yetanotherchris on Jun 12, 2007 10:20:50 GMT -5
Cool, thanks for the response.
I'll try rewiring the jack the other way round and see what happens.
Right now the guitar plays fine, it's just noisy and poppy. Admittedly I haven't tried the jack the other way round since I removed the tone pot, so we'll see! I'll get back with some photos soon enough
Post by michaelcbell on Jun 13, 2007 7:24:29 GMT -5
I also would wholeheartedly recommend the QTB mod, but I'm pretty sure that's not all of our problem here - especially since it isn't as loud when the jack is reversed. Let's see what yetanotherchris finds out and we'll go from there.