Input and Output Jacks

[pdf64]

No, the cap goes between the jack’s sleeve terminal and a convenient chassis connection in close proximity.

[ChopSauce]

Ok, so the jack base wouldn't be connected to the ground but through the cap...

... & in the case of a ground bus, that would mean I solder a cap - instead of a bit of wire - to the bus, right?

[pdf64]

Ok, so the jack base wouldn't be connected to the ground but through the cap...

... & in the case of a ground bus, that would mean I solder a cap - instead of a bit of wire - to the bus, right?

The jack’s sleeve terminal must also make a connection to the amp’s 0V common system.
Unless using a single star ground arrangement (?), I think you may as well just get rid of the jack’s insulating washers.

[ChopSauce]

Ok, let's assume that my jack is grounded through its bolting. So finally I understand that the cap would simply be in parallel with a "perfect" connection to ground...
(otherwise could you please describe it in plain english if there's no such thing as a sketch that you could show?)

I wonder how that works...

[pdf64]

With a non insulated jack, the cap would pointless, of no benefit. Sorry I wasn’t clear about that.

[ChopSauce]

Ok, so let me recall you that I have isolated jacks.

How am I supposed to solder the caps: close to the jack in parallel with the connection to ground, this latter being at the socket?

[pdf64]

If you’re using isolated jacks, I don’t understand how you can be making an 0V to chassis connection at the socket?
Perhaps you mean that it’s being done in close proximity?
Schematic, layout, photos?

[TUBEDUDE]

Since you're not using feedback from the OT, I would not ground the output jack. Isolate it from the chassis with a plastic or fiber washer. There's no loss of stability and it will keep high current out of the chassis.

[pdf64]

Since you're not using feedback from the OT, I would not ground the output jack. Isolate it from the chassis with a plastic or fiber washer. There's no loss of stability and it will keep high current out of the chassis.

I disagree, this is a circuit that the user will be exposed to, so it's safer to reference the speaker output to earth, eg in case the OT shorts primary to secondary.
And with no NFB, if the sleeve is connected to chassis 0V, what circuit nodes is the current in the chassis going to flow between? (my answer - I think there's only the one node, at the jack, so no OT secondary current can flow via the chassis).

[Phil_S]

I suspect there is disagreement about almost nothing here, or maybe we just don't have enough information. Either he's using a nylon shoulder washer with a Switchcraft type jack or a Cliffs style jack, which is all plastic where it goes through the chassis. Either way, there is no ground made at the hole in the chassis. Since we can't see what the OP has in mind, we may be jumping to conclusions. The reason I say this is that I'm doubtful the speaker ground is left floating. When I do it this way, I run a ground wire from the sleeve/ring connection to the main filter cap chassis ground point.

Maybe we can get some facts to help understand more precisely about the question being asked?

I have a feeling we all agree that the speaker ground should not be left floating. Well, maybe I'm not right about what others think.