a couple of layout questions

[woogie]

i'm looking at the latest 36w layout and i see what looks like 3 different colors on the wiring from the treble pot to the master volume pot. Is there supposed to be jumper wires from the right and middle terminals to the grounded terminal on the master volume? Is this indicating shielded wire? Also i want a presence pot instead of an nfb on off switch. can i eliminate the switch and run a wire from the 8 ohm jack to the .1uf that is connected to the PI circuit and then to a 47K resistor then to the right terminal of a pot with a .1uf across the middle and left terminals?

[NitroLiq]

i'm looking at the latest 36w layout and i see what looks like 3 different colors on the wiring from the treble pot to the master volume pot. Is there supposed to be jumper wires from the right and middle terminals to the grounded terminal on the master volume? Is this indicating shielded wire?

The gray wires with the blue ends represent shielded wire. If you look at the master volume and the short shielded graphic with the letter "D" above it", you'll see the same thing coming off the cap next to the PI on the board. That's the connection. We used letters to notate some of the shielded connections to keep the layout clean...if I drew them out, it would've been misleading as I would've had to draw long runs when the idea is to keep them as short as possible.

[woogie]

Thanks Nitro. Any opinions on my nfb switch question?

[NitroLiq]

That'd be a question for someone with more experience...I'm still pretty green with amp building and circuits in general.

[markh]

Thanks Nitro. Any opinions on my nfb switch question?

I'm not absolutely sure based on yor description, but if you just duplicate the presence control from any older Marshall schematic you should be fine.

--mark h

[rjgtr]

I actually think a Cut control is more useful than a presence control on an EL84 based amp. You might consider one for reducing high end.