Ground terminal on M2.

belgianbrain

Super Member
Out of curiosity, this M2 has a ground terminal that looks like the type found on the backs of record players.

Is this terminal for connection to a record player, or is one required to attempt to connect this terminal on the M2 to ground?
 
Oh, I have the manual, Avionic.

This is my first separate power amp (I have a few integrateds), so excuse my ignorance if this grounding scheme is typical in separates world. But, it's just had me scratching my head since I saw it. If the amp wants an earth ground, why isn't it equipped with a 3 prong cord?

So, I was wondering, is the earth connection optional (i.e., intended for sonics only), or is there also a safety component to it?

I detect no noise coming from my speakers when the amp is idle.

...and where would I attach it? The preamp I built could easily be fitted with a ground connection I guess (I designed it with a 3 prong cord as I do all my projects). But, from the schematic in that manual, it seems the Yamaha preamp wouldn't even have a place to connect an earth ground.

Is it me, or is this weird?
 
Ground it to a cold water pipe.
why isn't it equipped with a 3 prong cord?
Good question. Suggest contacting Yamaha engineering and get to the bottom of this issue.Pronto!
 
Funny.

I don't think my sound system has ever been close to the plumbing, anywhere I've lived..

Could also ground it to the center screw on the wall receptacle provided the box is grounded. I have and older house and the boxes were not grounded. So I ran ground connections to the boxes from ---the cold water pipe!
 
Could also ground it to the center screw on the wall receptacle provided the box is grounded. I have and older house and the boxes were not grounded. So I ran ground connections to the boxes from ---the cold water pipe!

Hmmm...maybe when I have a chance, I'd add a grounding connection on my preamp.

Hopefully this won't create a ground loop!

I assume based on the way this is setup that this ground connection is not needed for safety reasons... Personally, I like to see 3 pronged plugs on everything.

I've been playing with the idea of opening this M2 up and bypassing the volume control on the back. I'm concerned those old pots might be adding some unwanted character to the sound. Anyone feel free to chime in if you have thoughts on this.
 
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i have equipment with ground lift switches to combat loops . if your doesn't suffer noise i would leave it be .
 
I've been playing with the idea of opening this M2 up and bypassing the volume control on the back. I'm concerned those old pots might be adding some unwanted character to the sound
You would not gain dittly squat. Would be the same as just setting them at zero attenuation.
 
You would not gain dittly squat. Would be the same as just setting them at zero attenuation.

I suspected that. But I'm a perfectionist with too much time on my hands. :D

You just dropped my motivation to try that down several notches, though...
 
Hmmm...maybe when I have a chance, I'd add a grounding connection on my preamp.

Hopefully this won't create a ground loop!

That MAY create a ground loop. If it's quiet now let it be... if it aint broke dont fix it as they say. Funny thing tho I recently purchased an Yammy 7.1 AVR new unit and it had a 2 prong plug. Class 2 device - kinda like a power drill, you are protected. Hum is a different animal cause not all your audio devices are classed the same and have differing grounding schemes as well as your house circuits. Best to leave it be if its running silent. Can-o-worms.. best left alone. My advice...

Cheers,
Bob
 
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