I have a customer who plugs his amp into a regular plug with no gnd. He is complaining of some weird noises when he touches the strings and some other things he seems to think it is a problem with the power. I have no clue what makes an amp work or if it should be on a iso gnd. Ant muscians or otherwise out there have any insight.
Guitar amp.
- Thread starter jes25
- Start date
- Status
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Guitar amp.
Could be a few things:
Problems in the amp. Ie bad tubes, or other components.
Miss wired or bad cord to guitar.
Bad jack wiring on guitar.
If the polarity at the receptacle checks out ans the neutral is not connected to the grounding conductor then your done.
A lost shield any where from the amp to the pickups will cause the amp to hum when someone touches the strings.
Could be a few things:
Problems in the amp. Ie bad tubes, or other components.
Miss wired or bad cord to guitar.
Bad jack wiring on guitar.
If the polarity at the receptacle checks out ans the neutral is not connected to the grounding conductor then your done.
A lost shield any where from the amp to the pickups will cause the amp to hum when someone touches the strings.
bphgravity
Senior Member
- Location
- Florida
Re: Guitar amp.
Maybe he is just a bad guitar player?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Guitar amp.
LOL
LOL Bryan
LOL Bryan
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Guitar amp.
What happens when the amp is used on a circuit with an equipment ground? How old is the amp?
What happens when the amp is used on a circuit with an equipment ground? How old is the amp?
bensonelectric
Senior Member
Re: Guitar amp.
I am slightly confused at the suggestion to buy a compressor/limiter. It was my understanding that a compressor is normally used to "curve" off the top of an incoming signal... I could see the use of a gate here, which would short out the input, when he wasnt playing, preventing the cord from acting as an antenna...
I am slightly confused at the suggestion to buy a compressor/limiter. It was my understanding that a compressor is normally used to "curve" off the top of an incoming signal... I could see the use of a gate here, which would short out the input, when he wasnt playing, preventing the cord from acting as an antenna...
izak
Senior Member
- Location
- Springfield, MO
Re: Guitar amp.
this is a very common problem i have had when using cheap guitars and amps.....
i agree that the guitar/amp combo is a huge antenna... ive had amps pick up radio signals, tv signals, Computer power supplies, CAKE MIXERS....
just deal with it usually....
this is a very common problem i have had when using cheap guitars and amps.....
i agree that the guitar/amp combo is a huge antenna... ive had amps pick up radio signals, tv signals, Computer power supplies, CAKE MIXERS....
just deal with it usually....
bensonelectric
Senior Member
Re: Guitar amp.
Its easy enough to get compressors, limiters, and gates mixed up, because they usually will all come in one box, and basically do the same thing. Compressors wait till an input level, in dB gets to a certain point, and then curve off the top of the signal, usually at a compression rate between 1:2 and 1:4 where limiters do the same thing, only the compression rate is higher, usually 1:4 up to 1:32. Gates do the same thing as both compressors and limiters, only instead of curing off a signal, it just clips it, or it can also be set to wait for an incoming signal before it "closes", this is useful for when you have cheap unshielded cables, that will pick up anything from AM to microwave ovens
edit for spelling
[ January 23, 2005, 02:12 AM: Message edited by: bensonelectric ]
Its easy enough to get compressors, limiters, and gates mixed up, because they usually will all come in one box, and basically do the same thing. Compressors wait till an input level, in dB gets to a certain point, and then curve off the top of the signal, usually at a compression rate between 1:2 and 1:4 where limiters do the same thing, only the compression rate is higher, usually 1:4 up to 1:32. Gates do the same thing as both compressors and limiters, only instead of curing off a signal, it just clips it, or it can also be set to wait for an incoming signal before it "closes", this is useful for when you have cheap unshielded cables, that will pick up anything from AM to microwave ovens
edit for spelling
[ January 23, 2005, 02:12 AM: Message edited by: bensonelectric ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Guitar amp.
Not me
I just do the roadie thing and install PA system's Mainly Electro Voice?, Crown Amps?, Rane? EQ's, DBA? compression limiters/ Gate keeper's I use the soft knee over, to not color the sound too much. And all my connections are done with Switch Craft? ?"phono, XLR jack's and snakes.
Not me
I just do the roadie thing and install PA system's Mainly Electro Voice?, Crown Amps?, Rane? EQ's, DBA? compression limiters/ Gate keeper's I use the soft knee over, to not color the sound too much. And all my connections are done with Switch Craft? ?"phono, XLR jack's and snakes.
physis
Senior Member
Re: Guitar amp.
So are you in or out Matt? You sound like you're in.
I have to argue about noise being the cable though. When I had cheaper stuff I tried everything in the known universe to fix it at the cable, all to no avail. Man did I hate that noise.
Well that splains your noise knowledge Wayne. What about balanced lines? Impedance matched transformers at both ends, two signal wires between the transformers, induced noise really cancels just like the EMF canceling in the 3way threads. DIN connectors. I've only played with those configurations. I assumed the pros must use those.
Did you ever get a chance to just goof off for a bit with someone's guitar with like 200 decibles worth of Marshalls on the overdriven input with the gain all the way up and just gobbs of distortion and harmonics are flyin all over the place and the feedback makes every note you stop on twice as loud and I'm sittin here making those Tim Taylor grunting noises and my girlfriend's looking at me like whatever it is I'm doing I should stop it.
Sorry, I got a little carried away.
Editted to use Matt's name.
Edit II: You are right though about the cable Matt in that the balanced line removes a lot of noise. But sheilded is sheilded.
[ January 23, 2005, 05:15 AM: Message edited by: physis ]
So are you in or out Matt? You sound like you're in.
I have to argue about noise being the cable though. When I had cheaper stuff I tried everything in the known universe to fix it at the cable, all to no avail. Man did I hate that noise.
Well that splains your noise knowledge Wayne. What about balanced lines? Impedance matched transformers at both ends, two signal wires between the transformers, induced noise really cancels just like the EMF canceling in the 3way threads. DIN connectors. I've only played with those configurations. I assumed the pros must use those.
Did you ever get a chance to just goof off for a bit with someone's guitar with like 200 decibles worth of Marshalls on the overdriven input with the gain all the way up and just gobbs of distortion and harmonics are flyin all over the place and the feedback makes every note you stop on twice as loud and I'm sittin here making those Tim Taylor grunting noises and my girlfriend's looking at me like whatever it is I'm doing I should stop it.
Sorry, I got a little carried away.
Editted to use Matt's name.
Edit II: You are right though about the cable Matt in that the balanced line removes a lot of noise. But sheilded is sheilded.
[ January 23, 2005, 05:15 AM: Message edited by: physis ]
jrdsg
Senior Member
- Location
- Vancouver, Canada
Re: Guitar amp.
this is cool...
http://www.furmansound.com/products/pro/blncd/balanced1.php
balanced power is an expensive, if effective noise attenuator.
if you are interested in building tube amps check out www.ax84.com
...rickenbacker 381JK
...homemade tube pre-amp
...workin'on a homemade 2x10 tube amp in a 1930's vintage radio cabinet. sweet.
-jr
this is cool...
http://www.furmansound.com/products/pro/blncd/balanced1.php
balanced power is an expensive, if effective noise attenuator.
if you are interested in building tube amps check out www.ax84.com
...rickenbacker 381JK
...homemade tube pre-amp
...workin'on a homemade 2x10 tube amp in a 1930's vintage radio cabinet. sweet.
-jr
davedottcom
Senior Member
Re: Guitar amp.
[ March 08, 2005, 06:52 AM: Message edited by: davedottcom ]
[ March 08, 2005, 06:52 AM: Message edited by: davedottcom ]
davedottcom
Senior Member
Re: Guitar amp.
"this is a very common problem i have had when using cheap guitars and amps.."
I had a similar problem in my old house. Drove me crazy! and believe me my Les Paul Custom & Fender Hot Rod Deluxe Amp aint cheap!
I tried everything...the first thing to make a difference was moving the breaker for the outlet to the other phase in the panel...then shutting off the laundry room florescent!...and the MOST interference was caused by a nearby dimmer. I couldn't even turn the dimmer all the way up, had to shut it OFF! No dimmer, no noise!
Dave
Gibson "Les Paul Custom"
Fender Strat (Tuned down with Texas pickups) for that SRV sound!
Martin DM Acoustic
Ibanez (Acoustic-Electric)
"this is a very common problem i have had when using cheap guitars and amps.."
I had a similar problem in my old house. Drove me crazy! and believe me my Les Paul Custom & Fender Hot Rod Deluxe Amp aint cheap!
I tried everything...the first thing to make a difference was moving the breaker for the outlet to the other phase in the panel...then shutting off the laundry room florescent!...and the MOST interference was caused by a nearby dimmer. I couldn't even turn the dimmer all the way up, had to shut it OFF! No dimmer, no noise!
Dave
Gibson "Les Paul Custom"
Fender Strat (Tuned down with Texas pickups) for that SRV sound!
Martin DM Acoustic
Ibanez (Acoustic-Electric)
- Status