Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => The Newcomer's Forum => Topic started by: ohvnaq on October 03, 2012, 03:36:49 PM

Title: grounding 3 pin amp with 2 pin socket
Post by: ohvnaq on October 03, 2012, 03:36:49 PM
hi guys! i'm new here - and new to electronics as well

i got an old yamaha solid state amp which has 3 pins, but the power supply where i live only has 2 pin sockets. what's a good way to ground it? i've had zaps on my fingers after playing long sessions on this amp.

i suppose i can connect the chassis to a grounding metal object? this seems a little awkward though and i wonder if there's a more elegant way

thanks a lot!
Title: Re: grounding 3 pin amp with 2 pin socket
Post by: Enzo on October 03, 2012, 07:00:00 PM
WHICH old Yamaha?

Does your power switch have two ON positions?  As in center position is OFF and toward either end is ON?  If so, try switching it to the other ON position.  That reverses ground connections.   Also, sometimes turning the plug 180 degrees in the wall outlet can do the same.   And of course if the amp has a separate GROUND switch, try changing that.
Title: Re: grounding 3 pin amp with 2 pin socket
Post by: ohvnaq on October 04, 2012, 01:30:58 AM
hi Enzo, thanks for the reply

the model is Yamaha GA-10

there's just the basic ON-OFF power switch

btw i should add to the question that basically what i want to do is to find an elegant way to ground the 3rd pin (which is wired to the chassis) so that it works even when i carry my amp around to practices or gigs. it's 2 pins everywhere here!

my best idea so far is to wire the chassis to an alligator clip and just improvise with the venue - find a metal pole that's connected to ground and clip it there, i guess

please enlighten me further, thanks a lot
Title: Re: grounding 3 pin amp with 2 pin socket
Post by: DrGonz78 on October 04, 2012, 03:31:05 AM
Personally I would say that you need to start updating your power plugs in your home. Why would you not want to update, at least some of them around the house?

You could install on the amp a polarized power switch (probably a bad idea) and in conjunction w/ some other type of ground scheme chassis clip. That way you have control of ground loops that might occur w/ other devices that are on stage and then you could flip Hot and Neutral around to make sure there is no buzz too...

Why not just get a 3 to 2 ground lifted plug adapter>>>

http://www.filmtools.com/grliadco41.html (http://www.filmtools.com/grliadco41.html)

That way you can just plug straight into the now grounded power strip. Just got to bring a screw driver with you or just a piece of insulated wire to connect it to be grounded somehow. I would recommend just screwing in the lifted ground into the screw on the 2 prong face plate on the wall. Well the screw will only work if it is ground, but there still might be hope if you can find something that is grounded to connect to it. However, this is still not that safe and only is to reduce noise. The best solution is to have grounded outlets that connect to a GFI.
Title: Re: grounding 3 pin amp with 2 pin socket
Post by: Loudthud on October 04, 2012, 11:31:27 AM
What country are you in and what is the nominal power line voltage? I think some of the replys assumed you were in the USA. The alligator clip might be the best and only option but you still may get a shock if you touch another guitar player or microphone if they are not also grounded.
Title: Re: grounding 3 pin amp with 2 pin socket
Post by: Roly on October 05, 2012, 01:34:32 AM
{Quietly horrified 3-wire Aussie   :o   :-X }
Title: Re: grounding 3 pin amp with 2 pin socket
Post by: ohvnaq on October 10, 2012, 02:14:56 AM
@DrGonz78 the adapter looks cool but unfortunately i don't think the sockets around here suit it

@Loudthud i live in vietnam and it's 220v and it's always been 2 pin sockets here since i was born

@Roly ;)

i guess i'll try the alligator clip thing to see how it goes. anyway thanks a lot guys for the help, really appreciate it!