A hum I can live without - need help!

[Structo]

I followed the Brown Note layout and it seems quiet.

[ampdork]

Heistl can I ask about this V3 grounding scheme?
Where did you see this method used?
From what I can gather I have only seen V3 grounded along with V! and V2.
I think I have seen the screens ground near the tube socket and perhaps I have seen one where it was taken to the power amp out.
For the life of me though I can't find V3 grounding at the rear.
What am I missing?

[ayan]

Heistl can I ask about this V3 grounding scheme?
Where did you see this method used?
From what I can gather I have only seen V3 grounded along with V! and V2.
I think I have seen the screens ground near the tube socket and perhaps I have seen one where it was taken to the power amp out.
For the life of me though I can't find V3 grounding at the rear.
What am I missing?

OK, this is a picture of 124. Look at the black wire on the SEND jack... it is the ground for V3.

Cheers,

Gil

[ampdork]

Man that amp drives my eyes buggy.
I sure hate to argue with the man who brought us these pics and surely knows far more than I but Gil is that not the presence ground?
If not does the presence tie into it somewhere that I can't find?

Also am I correct in that the later ODS with the precision power supply does indeed ground V3 along with V1 and V2 or am I missing something there as well?

Should I be doing surgery to my amp?

[ayan]

Man that amp drives my eyes buggy.
I sure hate to argue with the man who brought us these pics and surely knows far more than I but Gil is that not the presence ground?
If not does the presence tie into it somewhere that I can't find?

Also am I correct in that the later ODS with the precision power supply does indeed ground V3 along with V1 and V2 or am I missing something there as well?

Should I be doing surgery to my amp?

Let's clarify one thing: the presence cap and the 390 ohm resistor are tied together at the preamp board, are they not? If so, the presence gorund is the PI tail's gorund.

Gil

[heisthl]

The real pictures I've looked at have all had nothing soldered to the presence pot except 2 wires with all the presence components on the PI area of the board and the ground at the jacks. I used to mount the tail resistor and the presence cap on the pot and ground to the pot buss, but after I tried for an exact copy I switched to this method.

On one of the other Dumble Discussion topics I made the comment that everyone should try and copy a real HAD build once and that they would come away from the experience building differently from then on. For me, this is a perfect example.

After saying all that, if your using a can cap this doesn't apply because your stuck with a common filter ground and you might as well use isolated jacks and a "Star" configuration for grounding.

[ampdork]

The V3 supply gets grounded at the rear panel preout pwrin jacks

I believe the word supply just threw me off here. That and absent minded reading. I was speaking about the grounding of the power supply nodes.

On one of the other Dumble Discussion topics I made the comment that everyone should try and copy a real HAD build once and that they would come away from the experience building differently from then on. For me, this is a perfect example.

Agreed. This is why I was in a mild panic as I thought I had it licked. As it stands I have never grounded the presence to the buss bar except maybe years ago along with M150's, wrong iron, wrong tubes, wrong everything...
I have learned the hard way that things are much easier when you defer to lead dress that is in the amplifier who's tone your trying to capture.
Just making sure I didn't need to change things up.
Sorry to add any confusion.

[heisthl]

Heistl can I ask about this V3 grounding scheme?
Where did you see this method used?
From what I can gather I have only seen V3 grounded along with V! and V2.
I think I have seen the screens ground near the tube socket and perhaps I have seen one where it was taken to the power amp out.
For the life of me though I can't find V3 grounding at the rear.
What am I missing?

Your right - sorry to mislead you there - the Funk boards (and the real precision style ones) Have the last 3 PS filters tied together which should be grounded at the front potbuss/input jack point.