| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1798.1 | | BTOVT::BAGDY_M | E=mc� - the formula for beer bubbles ! | Tue Apr 24 1990 16:28 | 8 |
|
Almost forgot one other tidbit of information.
The ground noise does go away when I touch the
pots/knobs. (Of course, since I'm supplying the
ground. :^)) Just wanted to include everything.
Thanks again.
Matt
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| 1798.2 | Try connecting the bridge to the ground | CSC32::MOLLER | Hit by a truck, License # RDB31A | Tue Apr 24 1990 17:05 | 9 |
| All of my guitars have the bridge grounded, so that when I touch
the strings, they are grounded to me. I'll lay odds on it that
your guitar was originally wired that way also. Is there some
reason that you don't want to do this?
You might want to check your power amp's polarity switch, as this
might also effect the noise level.
Jens
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| 1798.3 | Shielding? Gee... does this sound familiar or what? | SALEM::ABATELLI | I don't need no stinkin' Boogie | Tue Apr 24 1990 18:04 | 12 |
| Here we go again...
Grounding is a essential whether you like it or not. Ground
it and quiet the noise, or leave it be and keep the noise. On ALL
of my guitars I've soldered a wire to all the pots, switches (if
possible), to the tailpiece and finally to the return/ground side
of the �" output jack. Placing some shielding material where ever
you can is great, but you need to finish the job by placing as much
as possible "inside" that loop.
Good luck!
Fred
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| 1798.4 | | BTOVT::BAGDY_M | E=mc� - the formula for beer bubbles ! | Wed Apr 25 1990 06:26 | 35 |
|
RE: .2
Well, the guitar did have the bridge wired up
into the rest of the mess, but it had a ground
hum then as well. Not as bad but still enough
to bother me. That's kinda' the reason I went
for a total rebuild. When I ran the foil for the
pots, I did run a little more to one of the
bridge posts, so yes, the strings/bridge were
grounded. (Guess I forgot about that. Whoops !
:^))
RE: .3
There is a wire running between the pots and
at least one of the switches. The other two are
a phase and single coil phase. (Don't have the
spec sheet right here to be exact) Should I put
some foil down under all three of the switches as
well ? (With maybe a little grounding the pickup
selector switch too ?) Like I said, this was a
pre-wired setup and probably more for a modern
guitar than a mid-60's model. I just can't think
of anything else that could be causing it.
Oh yeah, the amp is a Yamaha Bass series, but
I've also got a little practice amp (kinda' like
a Pignose) and I still get the hum through that.
It's gotta' be the guitar side as far as I can
see.
Thanks again for any and all help !
Matt
|
| 1798.7 | Hum loops maybe.. | MAMIE::FRASER | A.N.D.Y.-Yet Another Dyslexic Noter | Wed Apr 25 1990 09:19 | 49 |
| Hmmm, I used to do electronics for a living, until I joined
DEC!
Some general points: previous replies are correct, in that you
need a good solid soldered ground all the way through the
guitar - ie. no metal parts should be 'floating'.
One important thing that I haven't seen mentioned is that it's
possible to have what's called a 'ground loop', and this is
hard to describe. Maybe simpler to describe what you should
have, and that's a 'star' ground.
Take, for example the output jack of the guitar - it has a
signal centre and a ground shell. In this case, we'll make the
ground shell contact the star centre. What you do is run a
number of ground wires to this common point, avoiding multiple
ground connections around the pots and pickups - something like
this:
Jack socket
---------
============+ signal
-------------\ ground----------switch----switch
/ |\
/ | \ gnd gnd
/ | \---------pickup---------pickup
bridge---------/ |
|
|
pot-----+-----pot
|
pot
The danger comes if you run a wire around from point to point,
trying to connect everything together - if there's a 'loop'
even if it's grounded at some point, you can get ferocious hum
from it. This could happen, say, if you connected the bridge
and then the tailpiece to ground - the loop would be formed
from ground, to tailpiece, through the strings to bridge and
back to ground and would act as an antenna. No amount of foil
or conductive paint will cure this completely.
Hope this helps...
Andy
PS Adding foil can give EXTRA grounds and cause hum loops...
|
| 1798.8 | Curious | AQUA::ROST | Bad imitation of Jerry Jemmott | Wed Apr 25 1990 09:44 | 7 |
|
Re: .7
Hey Andy, did you use to play bass in Free? 8^) 8^) 8^)
Brian
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| 1798.9 | RFI | DNEAST::GREVE_STEVE | If all else fails, take a nap... | Wed Apr 25 1990 10:19 | 10 |
|
Yep, I agree.. sounds to me like the RFI Filter (the foil) didn't
make connection with the ground lug.... I'd also "catch" the pickguard
screws...
Regards,
Steve
|
| 1798.10 | | BTOVT::BAGDY_M | E=mc� - the formula for beer bubbles ! | Thu Apr 26 1990 07:25 | 42 |
|
Well, as it turns out, I've found what the
problem was.
A friend of mine here in BTO came over yesterday
while I was ohming out the wiring and drew a
schematic of what I had. (For use to compare to
the original schematic.) Everything was wired
perfectly, with no shorts whatsoever. As it
turns out, when I lengthened the wires for the
single/dual coil, phase shift and pickup selector
switches, there was enough `slack' in the wire so
it ran very close to the pickups. As he told me,
it seems that I was picking up a low impedance
hum across the coils in the pickups. (These are
humbuckers too !)
So, I took it home and rewired those four
switches, and checked it out. Hmmm, still a
slight hum. Well, my girlfriend was playing
Nintendo and it seemed like the sound of the hum
kept changing as the screens on the game/tv were
changing. So I dragged out the rest of the 25'
patch cable and went into the kitchen. This
time, there was HARDLY and audible hum. It
turned out to be that `some' (maybe all, not
sure) of the hum/noise was being caused by the
Nintendo/TV. (Can't say it's one or the other,
cause there are times that it does it with the TV
on and there are time that it doesn't. Same goes
for the Nintendo. Maybe it just doesn't like
`Paperboy' or `Family Feud' ! :^))
So anyway, the guitar's finally back together and
strung up. Now all I have to do is finish
checking intonation across the fret-board.
Thanks again for all the help. I can finally get
back to six strings again, but it's gonna' be
weird playing with a pick again ! :^)
Matt
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| 1798.11 | | NEEPS::IRVINE | I think therefor I gotta headache | Thu Apr 26 1990 08:00 | 11 |
| Now that you have mentioned that Matt, I recall a problem I had
with my Strategy... When playing it in the house, if the dimmer
switch on the light was only half on (ie dimmed), I experience humming
from both single coil and humbucker pickup's. It could be that
there was insufficient RF screening on the Strategy, resulting in
a horrible hum *untill* the string were touched, when the hum
disappeared. Fortunately, I do not have this problem with the LP,
but I do experience a slight distortion when I am playing with the
GE-7 on, and I am using a clean sound!
Bonzo
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| 1798.12 | Dimmers suck! | COOKIE::G_HOUSE | Greg House - DTN 523-2722 | Thu Apr 26 1990 12:40 | 5 |
| Yeah, a big second on that one. I used to crash my friends SW based synth
(Ensonic EPS) every time I moved the dimmer switch when we played at my
house!
Greg (who's heard "GET AWAY FROM THAT!!!" a few times..._
|