Yeah that's correct the bus wire from volume 1 to the treble pot is replaced with a 100K resistor. It's a hangover from when the RP10 IICs had the + conversion done to them as Mike B leaves this resistor in place.
I should point out that the 100K on its own does NOTHING. But when combined with adding a 15uF on V2B cathode (the one with the 1.5K cathode resistor - the signal goes V1A > V1B > V2B > V2A > OUTPUT on the IIC+) it weirdly creates an additional gain boost. Can be used as a switchable ++ easily enough by switching the 15uF on V2B on and off with the 100K resistor hardwired in. Easier than adding in the relay and all the additional extras, but you lose the 3.3M/10 or 20pF addition. There are also some hard wired in changes to the lead circuit in a switchable ++ mod but I'm not sure on the exact effect of these. I normally keep it simple. Switchable 15uF off V2B is enough for me
See details and discussion of this fire breathing dragon mod here:
http://forum.grailtone.com/viewtopic.php?f=27&t=40649#p292545
I should point out that the 100K on its own does NOTHING. But when combined with adding a 15uF on V2B cathode (the one with the 1.5K cathode resistor - the signal goes V1A > V1B > V2B > V2A > OUTPUT on the IIC+) it weirdly creates an additional gain boost. Can be used as a switchable ++ easily enough by switching the 15uF on V2B on and off with the 100K resistor hardwired in. Easier than adding in the relay and all the additional extras, but you lose the 3.3M/10 or 20pF addition. There are also some hard wired in changes to the lead circuit in a switchable ++ mod but I'm not sure on the exact effect of these. I normally keep it simple. Switchable 15uF off V2B is enough for me
See details and discussion of this fire breathing dragon mod here:
http://forum.grailtone.com/viewtopic.php?f=27&t=40649#p292545