HOT Rod ckt grounding and Relays

I really didn't want to post this since I have read so much here on other Grounding threds, but here it goes.

I have to laugh man(or scream). Everything goes smoothly until I get to the grounding phase of a project. The last box of @PI's used RogerFoote's and Kieth's(sssltech's) scheeme where the PWR xfmr center tap was to chassis star, which went to JLM PSU 0VAC and I discarded the Audio Ground thing with no hum. (well other than pwr xfmr radiation in ch 4)

Anyway here I have a bunch of other stuff that's not as simple

25V avel lindberg -No CT- connected in parallel.

JLM PSU: 10R and cap to chassis
283BA & Hotrod: 10R to chassis
-HR also has chassis point, but this would have to go through the PS network to make it to 0VU and seems best to connect one or the other, right?

Carnhills: chassis gnd to chassis. No?

Relay Control PCBs on front with LEDs
Phantom cap neg and Relays share 0V on it's own PCB
Discrete 24V DI 0V -this uses a BJT to send 48V to relay PCB when ring and sleve short to ground.


It seems like a mess of ground references. Any thoughts?

PS. next plan is to figurte out how to set up a Constant current source and really mess things up.

I am guessing the above seemed like jibberish so here are some illustrations:

Method A -I think there is a mistake and that the Hot Rod signal ground should go to the JLM 0V.

Method B - w/o JLM Audio Ground filter


DI Relay Trigger using signal ground


My main concern was the DI ground which I guess is best going to the Hot Rod's Audio Ground tap. and the low side of the DI ends up at the Hot Rod after the xfmr. actually maybe the DI low side is of no concern since it will go to the I/P xfmr. I hope that trigger ckt isn't too finicky being 10R above ground.

I am leaning towards Method B. I am thinking it will keep Relay and Signal ground potentials more isolated.

Unfortunately I'm far from expert, but quiet confident that:

"JLM PSU: 10R and cap to chassis
283BA & Hotrod: 10R to chassis"

I've read around that 10R is not needed on the 283 side...
http://www.groupdiy.com/index.php?topic=15373&postdays=0&postorder=asc&start=60
(see the post by JLM)
Also pay attention to Neve grounding scheme (use cable shields as
on the Neve drawings)

Transformer to chassis- mine are connected like on your drawing-
no hum whatsoever (my PSU transformer is ext)

DI- don't know but it is not that difficult to check both options.
anyhow i would have pre working and than i would add
the rest...

good luck

m