FYI: I did not add this circuit to the primary winding transformer/AC plug side. That is called the safety ground. I have no interest putting something in the way of safety ground. This addition was put on the secondary transformer side for the audio ground. My instructions came from Kevin O'Connor. i.e. KOC and his TUT3 book, plus a little here,and a little there from Elliot Hi FI doc(link above), and the wizard pdf (
http://valvewizard2.webs.com/Grounding.pdf).
Elwood, it is interesting to hear you have the silver version. I read about those, but missed the opportunity to get one.
I too would like to know what other grounding techniques were done.
The amp I am building now was made from the Hammond rack mount chassis. There is a thick paint covering the metal.
Just last week, I tackled that paint problem so the whole chassis is connected together. Remember, if you are using rack mount chassis. One ground of one chassis is the same as another. Because they are all connected by the rack. And that is why ground loops are more susceptible, this contraption should help.
Right now my guitar is plugged into the Trio, but my bass is plugged into this guy
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But I still use the D75 for the power amp. Which, btw, is one versatile power amp. It is so cool.
)