passive gear grounding (balanced) ?

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I'll try and explain this as quickly and simply as possible. I'm building a passive, balanced piece of equipment for use in my recording studio. It consists of two input XLRs, two stepped attenuators, two 1:1 transformers and two output XLRs. I'm trying to sort out the grounding which wasn't supposed to be a problem with gear that doesn't even have an AC plug!
The circuit is as shown on this schematic:
http://www.jensen-transformers.com/as/as065.pdf
The only change that I have made is to insert a balanced, stepped attenuator in between each input XLR it's respective transformer. These attenuators will allow me to vary the ratio between the two signals. (I could have used a double unit, like a balance control, but there were advantages to using individual attenuators.) The whole thing gets stuffed in a 2RU rackmount enclosure.
My questions:
1. There are 3 ground connections shown for each of the two channels; the Pin#1 input ground (with the damping network), the transformer ground, and the Pin#1 output ground. Can these three grounds (six, really) all be tied together at a single chassis ground terminal? (would that be a "star" ground?)
2. The Shallco balanced ladder attenuators will each have a ground connector. Should these get wired straight back to the chassis ground terminal, or should they tie to the output XLR Pin#1?
Any other thoughts regarding grounding issues with balanced, passive equipment?
Thanks for your help!

Steve Pogact
lex125@pacbell.net

.
digital? I'm still not sure about transistors....

schematic of original Jensen circuit (Open in New Window)

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Topic - passive gear grounding (balanced) ? - hollywood_steve 20:50:15 04/05/02 (0)

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