R.G.'s Hum Free Signal Splitter: Ground Question

[gaussmarkov]

R.G.'s Hum Free Signal Splitter has two outputs isolated with transformers and one direct output, no output switching.  AFAICT the direct output provides the only means to ground the input side of the circuit. 

is the enclosure a satisfactory ground?  if not, where would you connect the ground of the direct output?  or why not run the direct output to one amp and an transformer-isolated output to the other?  (i am asking of this particular set up, where there is no switching between channels.)

thanks in advance, gm

[gaussmarkov]

more digging and i found a partial answer here, due (of course) to R.G. 

Maybe I'm missing something, but couldn't isolation be achieved
with just 1 transformer coupled output, and the "other" output coupled normally through the box.

Yep, it could. That would leave the input always connected to one amp's ground, and that probably would never cause any problems.

I used two because
(a) any tone effects from the buffers and transformers are sent equally to both outputs
and
(b) the circuit is the son of the transformer coupled splitter.

[tennisdude]

i did the above and it worked great! with both isolated there was noticable hum, with only one isolated it became hum free 

John

[gaussmarkov]

i did the above and it worked great! with both isolated there was noticable hum, with only one isolated it became hum free 

John

thanks, man!  i was wondering if this might happen, with no ground for the input.  i noticed today that generalguitargadgets has a warning about some folks getting hum with a circuit that has no "direct out," just two isolated output channels.  this might explain that.