Lt. Bob
Spread the Daf!
I just got a little Ampeg GVT-5H ................ tested it at the house ...... worked great.
Went to do a rehearsal and plugged in the little 10" cab I use with ALL my little 5 watt amps and got no sound ...... so I'm holding my git and reached around back to push the speaker plug and make sure it was all the way in and got the crap shocked outta me! I mean fairly highish voltage too ...... woke me right up!
So anyway ...... this cab, which I have used for years, has a hardwired cord with a 1/4 plug on the end. At the time I put the cord on I was in a hurry and only had a TRS plug handy so I just used that and left the ring disconnected. Never been a problem but apparently it was a problem with this amp. Once I got home and changed the plug to a standard 1/4" it worked fine.
For the life of me I can't figure out why using a 1/4" TRS would cause a high voltage potential between the input ground and the ground of the speaker jack if the ring on the TRS is not connected to anything.
I opened the amp up and nothing is burnt and it seems to work fine and didn't blow a fuse so it wasn't damaged apparently.
The speaker jacks in the amp look like they have 3 conductors although, of course, they must only use two for the output and they are isolated. And they are 'floating' output jacks isolated from the chassis.
But some of my other 5 watters have isolated jacks too and it's never been a problem 'till this one.
Any ideas?
.
Went to do a rehearsal and plugged in the little 10" cab I use with ALL my little 5 watt amps and got no sound ...... so I'm holding my git and reached around back to push the speaker plug and make sure it was all the way in and got the crap shocked outta me! I mean fairly highish voltage too ...... woke me right up!
So anyway ...... this cab, which I have used for years, has a hardwired cord with a 1/4 plug on the end. At the time I put the cord on I was in a hurry and only had a TRS plug handy so I just used that and left the ring disconnected. Never been a problem but apparently it was a problem with this amp. Once I got home and changed the plug to a standard 1/4" it worked fine.
For the life of me I can't figure out why using a 1/4" TRS would cause a high voltage potential between the input ground and the ground of the speaker jack if the ring on the TRS is not connected to anything.
I opened the amp up and nothing is burnt and it seems to work fine and didn't blow a fuse so it wasn't damaged apparently.
The speaker jacks in the amp look like they have 3 conductors although, of course, they must only use two for the output and they are isolated. And they are 'floating' output jacks isolated from the chassis.
But some of my other 5 watters have isolated jacks too and it's never been a problem 'till this one.
Any ideas?
.
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