Odd Hiwatt NFB?

[OrganicEffects]

Hello,

Looking at MHuss's 'Two Input Jimmy Page Preamp', it seems like the NFB/presence control just stops... compared to the SAP schematic, which seems to be the most similar to the JP aside from a few values and power routing. The SAP has the presence continuing back and fed into V3 pin 6. Would the circuit 'work' in the Jimmy Page Preamp as drawn, or do you think it meant to be as in the SAP schematic and made in error? Thank you.

JP Preamp: https://hiwatt.org/Schematics/DR_Pre2InputJP.gif
SAP Preamp: https://hiwatt.org/Schematics/DR_Pre2InputSAP.gif

[shooter]

thinking someone got a bad photo-copy or the mouse battery went dead 

pull up the schematics in different tabs, then toggle between them 10 times real fast 

[Tony Bones]

On the JP version, the NFB and presence control look like the typical Fender/Marshall circuit. The NFB is fed to the 'other' PI grid (and the tail resistor for bootstrapping, but that's not NFB in the usual sense.) It should work as expected.

On the SAP version the NFB is the same, but the presence control is more complicated. When the presence is turned up it reduces HF NFB, thus making the sound brighter as usual. But, when turned down it shunts some HF to ground before the PI, thus making the sound darker. There may be some subtlety that I'm missing, but I think that's the basic idea. The SAP is the usual Fender/Marshall NFB + presence, but with a little added functionality when the presence is turned down.