T.R | Title | User | Personal Name | Date | Lines |
---|
2380.1 | always answer with questions... Right? | ROYALT::BUSENBARK | | Thu Nov 21 1991 16:12 | 3 |
| Can you describe your equipment setup,ie pedals etc... and what
kind of lights are in the club?.... other enviromental conditions?
|
2380.2 | | PHAROS::SAKELARIS | | Thu Nov 21 1991 16:22 | 5 |
| Tho this may not be the problem, what you discribe is exactly what
happens if you have an unsheilded cable at somewhere between your amp
and guitar. Try swapping out the cables.
"sakman"
|
2380.3 | re: line hum | MRCSSE::WAIBLE | | Thu Nov 21 1991 17:05 | 12 |
| Thanks .1 Yes im playing a strero chorus 212 peavy amp 135w RMS. i
shouldnt have said pedals because all of the fucnrtionality is actually
in the amp itself connected to a 4 switch foot pedal which actuates
level 1 overdrive level 2 overdrive and chorus, reverb. When I go for
any overdrive at all the line hum is louder than the band. Yes there
are some rheostaed stage liughts nothing fancy, but even with them
tunrd off the problme persists. I'm thinking of 'floating' my ground by
getting a thre to two prong adapter. I'm bringing a meter tomorroow to
the gig to tell me what the gound conditions are on the line itself.
thanks fred
|
2380.4 | re: line hum | MRCSSE::WAIBLE | | Thu Nov 21 1991 17:07 | 6 |
| thanks sakman. I dont think this is the case because it seems to be
happening (altho to a much lesser degree) to otgher equipment (PA for
example) in the band.
-F
|
2380.5 | Some thoughts | BSS::STPALY::MOLLER | Fix it before it breaks | Thu Nov 21 1991 18:13 | 17 |
| Light dimmers anywhere one the same circuit cause the same
sort of noise problem (You usually hear it from the distortion
box because it has a huge gain - around 1000 to 10,000 - in
at least one stage). I've seen old ballast style floresent bulb
units cause the same sort of problem.
I suggest buying an AC line conditioner (adding surge suppression
is also a good idea) for at least your guitar amp and any AC
powered effects that you might be using. Most of these can't handle
more than 5 amps, so be careful that you don't overload the filter.
Another wonderful experiance that I've had was to play off of
a gas powered generator (My advice - get as long an extension cord
as you need and stay away from these monsters) - I'll never do it
again.
Jens
|
2380.6 | just a thought.... | BTOVT::BEST_G | when everything I feel changes | Fri Nov 22 1991 09:15 | 9 |
|
You might be able to get a real deal on one of those 1500lb., 20KW,
3-phase line conditioners they we were selling along with the
9000's....
;-)
guy
|
2380.7 | ex | MRCSSE::WAIBLE | | Fri Nov 22 1991 09:24 | 10 |
| Jens;
thanks for your thoughtful reply. With all lighting off, I would
think that any effect that adjustable rheostat or the effect of say a
floresent bulb would be absent. Anyway thanks for the advice, I'll
check out some ac scrubbers. Got any suggestions or what price range I
should be lookinbg at?
thanks -Fred
|
2380.8 | more questions.... | ROYALT::BUSENBARK | | Fri Nov 22 1991 11:27 | 8 |
| Fred,
I'm not familiar with the Peavey,is it a tube amp? the ungrounding
with the use of the adapter might be a start.
Rick
|
2380.9 | Shielding? | RGB::ROST | Boozoo Chavis underwear endorsee | Fri Nov 22 1991 11:45 | 13 |
| Fred,
Turn the amp up FULL BLAST with no git plugged in. If the hum is
absent, it's your guitar that's the problem. Check the shielding!!!!
Since you said it gets worse with overdrive, I'd suspect it first.
Brian
P.S. A quick check of how noisy an amp is can be done by inserting a
shorting plug (buy a 1/4" plug at Rat Shack, short the tip and sleeve
together) into an input jack to short the input to ground. This is a
*better* test than leaving the input open, as high impedance inputs can
pick up noise when unterminated.
|
2380.10 | ground lift...float the amp | OTOOA::ELLACOTT | pancake maverick | Fri Nov 22 1991 15:26 | 11 |
| I agree with .8
Get a "ground lift device" if you have a three prong plug (on the
things that disconnects the third prong). Be CAREFULL about how you set
up the polarity on the amp when using it. You need to use a voltmeter
to check to make sure the case of your amp isn't 'Hot' in regards to
other things around. If it it your strings and you will be too and if
you touch a grounded mic or lighting stand.....
FJE
|
2380.11 | Don't float it if you don't need to! | WEDOIT::ABATELLI | MESA BOOGIE modified by PEAVEY! | Sat Nov 23 1991 07:50 | 23 |
| HEY, WHERE YA GOING WITH THAT GROUND PIN!
I worked in a band where the bar owners didn't have grounded outlets,
so we ended up putting 3 to 2 prong convertors. There was no choice
for those bars, BUT I got bit big time one night when the PA power
cable was turned the wrong way (different polarity) in regards to my
guitar amp... get ready, set... SHOCK!!!!! (insert blue arc and
sharp pain on your face), it kicked me right back and fast too! Holy
smokes, what the heck was that? I checked it (after that tune) with a
DVM and it read 95VAC between my guitar bridge and the microphone!!!
Noticed after that the lead singer "cut" the ground pin cause he lost
his adaptor! Dumb or what? I switched the polarity, checked it again
(I forget what it was, but ALOT lower in voltage) and we were back in
business.
Rule of thumb:
Never float the amp if you can help it! If you *really* need to,
check for excessive voltage between your amp and the PA and if it's
high, switch the polarity on one (not both) and check it again.
Rock on,
Fred
|
2380.12 | that's a BOZO NO-NO!!!! | HAMER::KRON | Dem's not babies..dem's fidgets!! | Sat Nov 23 1991 18:36 | 3 |
| don't run without the safety ground if at all possible. If something
goes wrong with your gear or anything else you are touching it just
might keep you from meeting Jesus before your time....
|
2380.13 | | OTOOA::ELLACOTT | pancake maverick | Mon Nov 25 1991 09:43 | 11 |
| re -.1 & 2
My advise should be taken with the prvious two comments in mind.
YES, IT'S DANGEROUS!!!, if you're not careful, and 'floating' an amp
should only be used as a last resort. Most old amps don't have a three
prong plug anyway and with those (my Ampeg SVT included) the voltmeter
test should be done each time it gets plugged in. My test is to check
for AC voltage between the case of my amp and the third prong or case
on the power bar. No fried lips for me.......
FJE
|
2380.14 | | CAVLRY::BUCK | Buck in Bronco | Mon Nov 25 1991 09:57 | 4 |
| My old Marshall heads with the two prong plugs (and the ground wired to
the chassis!!!) were like assured shock givers (nasty shocks, too!).
Although, you get pretty proficient after a couple of nasty zaps at
turning it on/off with you pick. 8^)
|
2380.15 | | MANTHN::EDD | Where DID you get those shoes? | Mon Nov 25 1991 11:02 | 8 |
| I remember the time when I was rehearsing with my first band. I was
running thru my Ampeg bass amp, and the lead guitarist was into a
Dual Showman. He had this nasty habit of leaving the ends of his
strings just sticking out of his headstock. One of these happened to
touch one of my tuning keys and "ZAP!". I was amazed at the arc! I
still have part of his string WELDED to my tuning key!!!
Edd
|
2380.16 | A start point to fixing the problem | BSS::STPALY::MOLLER | Fix it before it breaks | Mon Nov 25 1991 16:14 | 54 |
| To find a line filter, go to an electronics supply shop. They
should be able to find you as many as you need. These often are
small, sealed, metal boxes with tabs that allow you to connect
your AC in, then connect an AC out. they are small enough for you
to put them into a metal outlet box (4 outlet - metal - like the
ones that you put into walls - with a steel cover). The wiring
is quite simple:
Wall Power Audio Gear
input connection (or outlets)
--------------
white | | white
---------[]| |[]------->
| |
|in out|
black | | black
---------[]| |[]------->
| 120V AC |
|Line Filter |
green | |
-----+---[]| | +--->
gnd | | | |
| -------------- |
| |
+------------------------+
These cost anywhere from $5.00 up (get at least 5 amp capability).
If you want to add surge suppressors, you can buy some at Radio
Shack (get the high powered ones), and wire them in (before the
filter in this manner:
white
-----------+-------+------------------
| |
[*] [*]
black | |
-----------+--+----|------------------
| |
[*] |
green | |
--------------+----+-------------------
These cost around $2.00 each (you'll need 3).
After all, you can get rid of a lot of line noise & prevent blowing
up gear all in the same box - why not make up some 25 foot extension
cables with these built in (You always need extension cords).
Jens
|
2380.17 | total amature | CSLALL::ONEILL | | Mon Dec 30 1991 13:55 | 19 |
| I hope this is the right place to ask this.....
Friday night, I played at a friends party in
his living room. I have a Gibson bass played through a fender
side kick. It has a three prong plug and the outlet excepted
this w/o an adaptor. In the room was your normal lighting and,
his christmas tree with I think a few other lit ornaments. I was
getting a buzz ( from the amp) that I had to mask with loads of
treble. I noticed if I stood faceing the amp and slowly turned
away till I was at a right angle, the buzz would decrease, then
increase as I continued to turn, ending with my back facing it.
Was it all the lighting causing this? Is there a way around it short
of turning off all the lights. How much do line conditioners cost?
Thanks, Jim
P.S. Im very new to the game of
setting to play for people.
|
2380.18 | Bad Ground | MSBNET::KELTZ | Old Hippie, Just trying to adjust! | Tue Dec 31 1991 10:24 | 4 |
| Sound's like yer friend has a bad ground in the 3 prong outlet you were plugged
into.
GONZO
|
2380.19 | Line filter is a good start | BSS::STPALY::MOLLER | Fix it before it breaks | Tue Dec 31 1991 12:25 | 8 |
| Or has something that is putting trash (florecent (sp?) bulbs & thier
ballast transformers are a common cause, as are light dimmers) onto the
power line & your guitar was picking it up. Good guitar shielding can help
here, as well as line filtering (one of the many reasons for the existance
of hum-bucking pickups - they cancel alot of this sort of noise).
Jens
|
2380.20 | Chopper dimmer switches? | HPSRAD::DZEKEVICH | | Tue Dec 31 1991 13:04 | 13 |
| Also look for any dimmer switches....they all use choppers, and do a
real job on AM radios and amps. Check to see if they have any remote
control power switches.....the type that send a signal down the power
line. The lamp control modules can dim....thus they have a chopper.
For the lamp modules, full "on" just means the fastest chop cycle. The
appliance modules have SCRs and no choppers. The wall mounted remote
switches with choppers aren't bad - they have a good ground.
So....watch for those chopper style dimmer switches.....they are real
hash generators.
Joe
|
2380.21 | Major RF pollution! | GOES11::G_HOUSE | Tommy The Cat | Tue Dec 31 1991 13:58 | 4 |
| ABSOLUTELY on the dimmer switches, those things SUCK! Wreck major havok
on cordless phones too...
gh
|
2380.22 | halogen floor lamps! | LEDS::BURATI | Mind the cat | Thu Jan 02 1992 12:44 | 5 |
| We have a dimmer switch on a ceiling light that I never found
to be much of a problem *BUT* we were recently given a set of
halogen floor lamps with dimmers on them and they generate more
line noise than anything i've ever heard before. See if there are
any of those hanging around.
|
2380.23 | | MANTHN::EDD | His bowtie is really a camera... | Thu Jan 02 1992 13:06 | 7 |
| Turning a dimmer control to "full bright" will often decrease or
elliminate the nasty buzz...
Ditto the quartz. I just put 3 lamps in my living room. Even the
PHONE picks up the buzz....
Edd
|