2 pronged connector

[audiophileboss]

Purchased a marantz sa8004 for kicks and giggles. The ac power socket at the back only accepts 2 pronged plugs, as it doesnt have a ground pin...so could I use a power cord with 3 prongs?

[mcandmar]

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww2.crutchfield.com.edgesuite.net%2Fpix.crutchfield.com%2FImageHandler%2Ffixedscale%2F400%2F300%2Fproducts%2F2010%2F23%2F642%2Fx642SA8004-B.jpeg&hash=860069ec8949236fb5dc3c03b9e7817319fab9fc)

Odd, never seen one of those sockets before, usually AV equipment without mains earth uses the figure 8 style connector.  But yes, a regular IEC cord will work fine.

[Gerry E.]

I use a Marantz SA-11S3 which also has a two connector power input jack.  I believe all of the Marantz digital players are like this.  They will except a three-prong plug but the ground will not be connected to anything.

Even given that, I'm able to hear differences between aftermarket power cords.  So did three other listeners who heard them in my system. 

I initially thought that Marantz doesn't include the ground connection because the players are grounded through the interconnect cables.  However, when I posted something about this on the Audio Asylum, someone else said it was because of the extensive shielding that Marantz uses internally.  I don't know if that makes sense and if it's true or not.

Gerry           

[Paul Joppa]

...
I initially thought that Marantz doesn't include the ground connection because the players are grounded through the interconnect cables.  However, when I posted something about this on the Audio Asylum, someone else said it was because of the extensive shielding that Marantz uses internally.  I don't know if that makes sense and if it's true or not.

Gerry         

Both are true. If an item, especially a signal source, is truly well shielded then the best noise performance over the widest range of circumstances will happen with no safety ground, only a signal ground. "Truly well shielded" is not at all easy to accomplish, especially when AC power is used, which is why other solutions are still practical in the real world.

I'll also note that a shielded power cord has the shield grounded at the wall socket, so it does provide a grounded shield for interfering signals that may be going into or coming out of the power wires.