• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

My bass amp shocks me!!

T

teenybasser

Guest
Aug 3, 2017
4
1
#1
I don't currently play much bass since I play regular guitar in the project I'm currently in. Since we don't have a bassist at all right now, we have a pedal that plays the backing tracks that include the bass and we plug it into my bass rig, which is an Ampeg SVT-450 and two 8 ohm cabs. Several years ago the gain knob got knocked off, leaving the metal underneath, and since I consider it mostly cosmetic and don't change the gain when playing actual bass guitar, I never replaced it. But we've had to change the the gain more often since we play the pedal though it. During the last month or so, every time I try to change the gain while the amp is on it delivers a shock that while all it does is jiggle my elbows and piss me off, I don't like playing around with any electrical shock and I'm aware of the possibility that it could get worse. I've even experimented with using a different amp and another outlet in the same room, and the same thing happens. I had an electrician look at it and he replaced one of the outlets, but I'm not sure he fixed it because I think he probably just saw that it was upside-down (with the ground prong on top) and replaced it. I tried testing the ground with a multimeter and it seemed fine, but I'm inexperienced and learned to do it from watching a tutorial, and I'm not sure I did it right. I also tried using the hot multimeter probe on the gain knob to see if it picked anything up, and it stayed at zero. This issue is just weird to me because my guitar amp has never done this, just both bass amps. And it seems to only happen when it has been on for a little while and is quite loud. Also when we don't have the pedal, I plug in my laptop, and I get shocked through the keyboard! I have not yet taken my amp to a technician, but that will be the next step. Also, the house was built in the '40's. I'm guessing grounding may have been different then. Thoughts are appreciated!

On a side note, when I first got this Ampeg the fan would not turn on, but from suggestions on this forum I was able to fix it since the fan connector turned out to be plugged in upside-down. I'm super grateful for that help, and I hope for more of the same! Thanks!
 
  • Like
Reactions: Bigbri
#4
Element Zero said:
... I can't believe someone has to tell you this but...


STOP PLAYING THE AMP AND GET IT PROPERLY SERVICED BY AN AMPLIFIER TECH!!!
Click to expand...

This!!

But if you really want to keep on playing with it in its current ( ;) ) condition, then at least invest in some safety equipment:

25.jpg
 
  • Like
Reactions: Dug2, DWBass, MichaelT and 9 others
#9
teenybasser said:
I don't currently play much bass since I play regular guitar in the project I'm currently in. Since we don't have a bassist at all right now, we have a pedal that plays the backing tracks that include the bass and we plug it into my bass rig, which is an Ampeg SVT-450 and two 8 ohm cabs. Several years ago the gain knob got knocked off, leaving the metal underneath, and since I consider it mostly cosmetic and don't change the gain when playing actual bass guitar, I never replaced it. But we've had to change the the gain more often since we play the pedal though it. During the last month or so, every time I try to change the gain while the amp is on it delivers a shock that while all it does is jiggle my elbows and piss me off, I don't like playing around with any electrical shock and I'm aware of the possibility that it could get worse. I've even experimented with using a different amp and another outlet in the same room, and the same thing happens. I had an electrician look at it and he replaced one of the outlets, but I'm not sure he fixed it because I think he probably just saw that it was upside-down (with the ground prong on top) and replaced it. I tried testing the ground with a multimeter and it seemed fine, but I'm inexperienced and learned to do it from watching a tutorial, and I'm not sure I did it right. I also tried using the hot multimeter probe on the gain knob to see if it picked anything up, and it stayed at zero. This issue is just weird to me because my guitar amp has never done this, just both bass amps. And it seems to only happen when it has been on for a little while and is quite loud. Also when we don't have the pedal, I plug in my laptop, and I get shocked through the keyboard! I have not yet taken my amp to a technician, but that will be the next step. Also, the house was built in the '40's. I'm guessing grounding may have been different then. Thoughts are appreciated!

On a side note, when I first got this Ampeg the fan would not turn on, but from suggestions on this forum I was able to fix it since the fan connector turned out to be plugged in upside-down. I'm super grateful for that help, and I hope for more of the same! Thanks!
Click to expand...

This thing is grounding to either the housing or the volume pot (???) and then to earth through your little feets when you touch it. Unplug and take tho a tech before it really hurts someone.
 
  • Like
Reactions: High Camp
#14
Get a new electrician. Ground up is code now. He uncoded you.
JACink said:
This!!

But if you really want to keep on playing with it in its current ( ;) ) condition, then at least invest in some safety equipment:

25.jpg
Click to expand...
Those certainly don't look like high voltage gloves. Gloves made to keep your hands clean may result in clean hands while being electrocuted. Not saying they are not high voltage rated, but they look like dish washing gloves in the picture.
 
#15
OP you there are a couple of possibilities here. The SVT has a faulty power cable and the ground is open. The socket you have the sVT plugged into has a broken ground circuit. The amp that your bass is plugged into has the above mentioned problems and there is nothing wrong with the SVT.

You need to have this looked at by a tech or electrician before someone gets hurt!
 
#17
Are you on a concrete floor when this occurs? Socks or bare-feet? If the house was wired in the 40's, it may not have a ground. Many buildings from that era just had a hot and neutral at the receptacles, which would leave your amp ground and chassis floating. Most tube amps have a degree of internal leakage which would account for the mild shock you've been receiving.
 
#20
byacey said:
Are you on a concrete floor when this occurs? Socks or bare-feet? If the house was wired in the 40's, it may not have a ground. Many buildings from that era just had a hot and neutral at the receptacles, which would leave your amp ground and chassis floating. Most tube amps have a degree of internal leakage which would account for the mild shock you've been receiving.
Click to expand...

Most (all?) of those houses had only two prong outlets without a ground, not three prong. OP just a hint, one end (black) of the multimeter needs to go to ground and the other to the exposed volume control to be able to measure any potential it may have. Then again your electrician may have found an open ground and since he had it open anyway just turned it around. What are you standing on when you get the shock, cement floor?, carpet? Have shoes on? Are you holding your guitar when you get shocked? You have to be getting grounded somehow or other.
 

Latest posts

Top Bottom
Back