Gounding Output Transformer

[thehoj]

I feel like this is something that I should probably know.. That being said I just want to confirm my thoughts.

I'll explain my current configuration to start with.
I'm using an isolated output jack. I have the 8ohm tap connected to the tip, and the common tap connected to the sleeve.. But I guess since this is the first time I have used an isolated output jack, I'm not actually grounding that common tap.. The amp works fine, but it's got a bit more hum than I would have expected.. I just realized, this common tap (connected to the sleeve of the output jack) should be grounded right?.. Seems like the best place might be at the ground point of the first filter cap.. Does that seem right?

What's happening with my amp when I've used it without having this common OT tap grounded?

[Enzo]

If your output is floating - not grounded - then your negative feedback is not doing much, as it lacks a complete circuit.


Does it hurt anything? No.

[thehoj]

Alright, well that makes sense, because the amp sounds pretty much like I had expected it to.
I'm not using negative feedback in the amp. Should I still ground that lug?

[g1]

Try it and see what it does for the hum issue.

[thehoj]

Alright, so I grounded the common tap on the output transformer at the same ground as the first filter cap, and it didn't really do anything for hum, but the hum was very minimal to be honest. I think it's well within what you'd expect from a tube amp.

The thing that definitely did improve though, is the sensitivity to positioning of my guitar. Prior to grounding this, the guitar would make that amp buzz LIKE CRAZY if it was close to the amp at all, or positioned a certain way.
Now it barely buzzes at all no matter where I stand with the guitar.

I guess this makes sense since my guitar wouldn't really have been grounded prior to grounding that sleeve on the output jack.
Interesting.