[TomS]

Hi Tom,

  Did you just float the gnd instead of using the jumper through the stand off?  Did you connect your signal gnds all together?  I think one box is gonna be easier and safer. 

My Aikido boards and HV power supply ground are just tied directly to chassis ground (star) using a wire and lug with star washer (teeth).  For the mono 9-pin board there is a jumper, j4 to either float or tie to chassis.  Mine is floated since I tie the power supply ground to the chassis directly.  There is nothing in the wood preamp chassis really to ground the standoff to.  And yes, 1 chassis is usually much simpler.

[sts9fan]

ok so is this how I should would star ground?



And is this how I I should ground the inputs and outputs with then + going to the source selector?

[JoshK]

I'd do it with the signal gnds and power grounds together and then go to safety earth. 

[sts9fan]

ok am I correct that if the botton is an aluminum plate that is a gnd plane so no need to connect them?

[TomS]

Yes, what JoshK said ...

Not sure what you mean, but any metal plates externally accessible (bottom plate) should be tied to earth ground.

[sts9fan]

right but if you have the power gnds at one point on the base plate and the signal at another and the safety right near the IEC they are connected via the plate. 

[JoshK]

I'd make your star ground not touch the chassis, deliberately isolated from the chassis and then run a thick gauge wire from the star ground to the earth ground (that is tied to the chassis) near the power entry.  This way you don't have unintentional currents running through the chassis.  Aluminum is only so-so conductive.  You want to have the currents run through the deliberate wire, not the chassis.

[sts9fan]

Fantastic!  Thanks for the clarification guys!

Kris

[ghpicard]

I'd make your star ground not touch the chassis, deliberately isolated from the chassis and then run a thick gauge wire from the star ground to the earth ground (that is tied to the chassis) near the power entry.  This way you don't have unintentional currents running through the chassis.  Aluminum is only so-so conductive.  You want to have the currents run through the deliberate wire, not the chassis.

IMO, using a resistor (or thermistor as Nelson Pass does) fits the bill better than the thick gauge wire... but as always, experimentation is needed.

[JoshK]

I agree, but in terms of the scheme for connecting things I wanted to be a bit more clear.  I typically use the yin/yang diodes in parrallel with a 10w resistor and small cap.