Hello lazytiger,
Here is the original reply :
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It's still seems like a grounding problem.
I probably don't need to tell you that it's hard to troubleshoot
anything without having the item in front of you. Here is what I
suggest :
1) Take the amp to your local music store.
2) Plug it into a floor model amp. Tell the guys you want to see what
'your' bass sounds like through the amp you are interested in. I
always do this before buying an amp.
3) If you still get the popping noise, then you may want to look into
the grounding of the pickups, or the jack on the amp itself.
4) Only after you have eliminated the bass and the amp would I
consider calling an electrician. (Save yourself money! ;-)
If you can do the above, or have access to a friends bass, let us know
the outcome. This will help narrow down the problem considerably.
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Aside from playing the guitar, I troubleshoot electronics fairly
often. A.C. hum/noise is a fairly common problem, and ensuring you
have a clean, solid ground connection can help reduce the adverse
effects.
If you do find that a problem also exists in the guitar, you can do a
few simple checks :
a) Buy or borrow a voltmeter. Something like this one will do well :
http://www.multimeterwarehouse.com/m810bf.htm ($8.99)
b) Check the resistance of your ground wires. These are wired differently,
depending on your pickups/guitar. Most guitars have a ground wire on the
input jack that connects to some type of internal shielding, with further
connections to the bridge to keep the ground potential the same.
c) You should read a short (~0 ohms) when checking straight wire points. Cold
or broken solder joints can lead to similar problems that you are seeing.
There are numerous other problems that could exist; more than I could
possibly list. However, with the advice sublime1 gave, and the
information here, you should have a very good start. I also found this
as I was closing up this question, and thought it may be of interest :
SWR SM 500 (you should have the same feature on your amp)
"The amp has no buzz at all unless you have bad wiring in your wall.
Actually the first 5 minutes were spent in panic, due to a ton of 60
cycle hum, but there is a ground lift function that is activated by
pulling out on the Line Out level knob on the back; this fixed the
situation immediately and ran hum free for the rest of the night...."
http://www.harmony-central.com/Guitar/Data/SWR/SM_500-01.html
Thanks for the question! Should you need further clarification feel
free to ask. I'll help as much as I can.
To assist with the last portion of this answer, I used Google to search for:
SWR SM900 hum
://www.google.com/search?q=SWR+SM900+hum
SgtCory |