ADA Depot - A Forum To Support Users of ADA Amplification Gear
Non ADA Gear => Guitars => Topic started by: potus2028 on November 12, 2015, 08:32:20 PM
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Hey all...need some help...
New project guitar build. 'Moved' my Ibanez RG550 into a new body. Full set of DiMarzios I've had forever, in perfect shape before the move.
Two issues:
First is a ground hum I cannot locate the source of. Been through five switches, two jacks, two volume pots, and redid the lead extensions on the neck pickup from scratch (clean job if I do say so myself). This ground hum is quite the mystery, as it comes in different 'forms' depending on where I am (shop vs. home). At the shop, it's only present in the full neck position on the switch. At home, it's there in all five positions. I've run it thtough two different cables and three different rigs - same thing. Before anyone says there's something wrong with my home electrical system, my other Ibanez displays no hum. Three different techs have been over this thing, and no one can figure it out. Only thing I havent done yet is change the tone pot, and redo the lead extensions on the bridge pickup. It 'should' not be in either of the pickups themselves...one go around on the wiring with a different switch had no hum, byt the switch itself was noisy as hell, so it went in the trash. I'm out of ideas. Anyone???
Second is even stranger...the switch itself is 'live'. Never seen anything like this in 25 years crawling around inside guitars. You know that sound a pickup makes when you tap a pole piece with a screwdriver when you're checking to see if it's hooked up right? The heads of the switch mounting screws on top of the body make the same sound when you touch them - with a FINGER! Can be heard no matter what position the switch is in. WTF???????
Anyone have any ideas on any of this and I'd be greatly appreciative. The guitar has come together magnificently, but is now driving me to jump off a bridge. Please help!
G
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Sounds like a shielding or a grounding issue :o
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Did you fround the switch (ground lead to the metal casing)?
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Switch is cleanly grounded to volume pot, along with everything else. Really clean star ground, if I do say so myself...that's always so tough to do well...
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Sounds like a shielding or a grounding issue :o
Definitely not a shielding issue...while there is no shielding (yet), and I do pick up rf noise, this is definitely a ground hum - completely disappears when you touch the bridge, less so with just touching the strings. Typical ground hum...
I think I'm more 'concerned' about the switch being 'live'...never seen anything like it before...
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Can you give some detailed info on what PU's and how they are wired to what?Or maybe better a schematic?
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Let me start by saying, I have no idea what you got going on there ;)
Second, I have two guitars at home that are not wired properly and they're KILLING me right now. I refuse to obsess about them, so I'll get to it later. My point is, I feel your pain brother, and I know you'll get it sorted out.
Good luck, and wish me luck as well
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Sounds like an open ground to me.
I suggest you disconnect all pickups and wire just one of them to your output jack directly. See if the hum disappears. Now add in the other components one at a time until you find the one that has the open ground.
You did ground the bridge, right?
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+1
Check if the ground wire (back of pot to trem spring claw) is attached and intact....
Post some close-ups of the electronics cavity...
What pups are in there? How do you have them/wanna have them wired?
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Thanks for the input everyone!
Update: I opened up my Ibanez S540 the other night, and found that while there is a Fender-style 5-way switch in there (I had no idea!), it is wired completely differently than the set-up I've been working with. H-S-H with reverse-wound center single, diagrammed best from the DiMarzio site, as their diagrams show a Fender-style switch, instead of the (silly) Ibanez YM-50 box-type switches. I reworked EVERYTHING again with this 'new' switch connection pattern, and the switch is no longer 'live"!
Still have the ground hum though. Ugh.
I have now:
1) cleaned up the extensions on all pickup leads.
2) New switch
3) New volume pot
4) Grounded and re-grounded every damn wire in the guitar
5) Stumped the hell out of three different 'professional' techs.
I have a problem thinking it's in one of the pickups themselves...they were perfectly fine before the 'move' Not sure how to wire them directly to the output jack to check...main hot lead to output, ground to ground, tape off the white/black taps?
Bridge ground 'should' be good - always the toughest joint to make - trem claws HATE solder...will check that again...
Thanks again!
G
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Can you give some detailed info on what PU's and how they are wired to what?Or maybe better a schematic?
Full slate of DiMarzios...Air Norton neck, Vai ISCV2 single middle (RW/RP), and a D Sonic bridge. Set up for typical Ibanez "split-5" wiring. Again, using a fender-style 5-way switch rather than the YM-50 style (hate those!)
This is what I was using until I changed it last night...
http://www.dimarzio.com/sites/default/files/diagrams/hsh5w_1v1t_&split2and4.pdf
http://www.dimarzio.com/sites/default/files/diagrams/hsh5w_1v1t_split2and4.pdf
"New" switch connection pattern found in the S540 is hard to describe...it's sort of reversed from this one, as if the switch was 'turned around', but not quite...hot and 'tapped' leads on opposite sides of the switch from above link, tap leads side-by-side on switch, not 'separated' by switch ground in as in the DiMarzio diagram...Switch works perfectly fine in this configuration, as far as pickup/coil selection goes.
The only thing I have not done at this point is change out the tone pot...guess that's what I'm doing tonight...
Thanks for the support, guys...I'll unveil her when we get this right...She's special.
G
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Hey poyus2028, with all these deliberations, suggest you put in a new (high qual) output socket/jack on your guitar (from post you haven't changed that out yet ??). Can't hurt and who knows...
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I actually did change the jack also...sorry I forgot with everything else! Not brand new, but came out of the same 'donor' MIJ RG that everything else came out of...
Here's a question - would or should it mean anything (in a diagnostic sense) that the ground hum disappears when the tone pot is 'off'??? Could it all be in there after all this time? The one thing I haven't changed yet?
Thx.
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Sounds like your tone pot ist toast. Disconnect the whole tone pot and give it a run with just the Vol pot. If the hum is gone, there's your solution :thumb-up:
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Sounds like your tone pot ist toast. Disconnect the whole tone pot and give it a run with just the Vol pot. If the hum is gone, there's your solution :thumb-up:
Brand new tone pot and cap put in last night...hum still there. This demon will not be exorcised...I'm losing it here...
Thought I'd found it in a bad bridge ground...nope.
Went back to the YM-50 that when last installed was noisy as f*ck, but no hum...nope.
Going to have to go the route of hooking the pickups directly to the output jack and check them. I can't think of another single thing I haven't done. It should not be in the pickups - they were fine before I moved them.
MOTHERPUSSBUCKET!!!!!!!!!!