Originally Posted by mdec
Originally Posted by GGA
[quote=tommypeters]I think it's the isolation transformer in the Digital Transport Edition of the modded Oppos that can't use balanced power. So just don't get a DTE.


It was stated: "On another issue: I saw the earlier discussion of the requirement NOT to use balanced power for the Oppo BRD-83 (modded or not)."

Replacing the original transformer with a toroidal "isolation" transformer should not change the circuit; however, adding a ground pin to a previously non-earth grounded system could change things, possibly for the worse, depending what the new ground pin is connected to, but I would still like to understand what is going on. Some manufacturers prefer to avoid connecting to earth ground, which can add noise and/or hum to a system.

Sirs, (and Gary if he's still with us),

My Digital Transport Mod with SPDIF connections is emitting a low frequency hum, which is being transmitted through the analog outs of the G68-->Mac amp-->surrounds-->hummmmmmmm.
Nothing through the 5200s thankfully. Never had this issue with Pioneer player.

It's there whether the player is plugged into wall or line conditioner (which is also plugged into the wall), and whether turned on or off.
Everything quiet only when unplugged. Is this the dreaded ground loop hum?

Although I never had this problem before I am thinking about purchasing a ground loop isolator. Would XLR connections from G68 to amplifier help?

Thanks for any other advice. Hope it's not the player.....
Edwin [/quote]

That sounds like a classic ground loop issue. Adding a component can cause that with many systems. It's clear indicator that it's ground loop since as you said there is no hum on 5200's and only on analog. You need to follow standard debug practices for finding a groud loop. Start a new thread in the main forum for advice.

- Fiddler (IMHO)

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