Fender Deluxe single channel

[dude]

A fender Deluxe single channel without reverb, the 220k before the cap to the PI, would this resistor be left out if a master volume was added here? Talking ab763 topology.
What would be the different with and without.

[shooter]

this one?


https://el34world.com/charts/Schematics/files/Fender/Fender_deluxe_aa763_schematic.pdf


if so those are mix resistors
if not post your version 

[shooter]

if no vibrato, make your MV the intensity pot, maybe 500k and move the tie point right of the 220k, maybe

[HotBluePlates]

... if a master volume was added here? Talking ab763 topology. ...

I have a sneaking suspicion turning an AB763 into a master volume amp will be disappointing.  There are many reasons the Boogie has a different preamp arrangement than the Princeton Reverb it evolved from.

[dude]

Yeah, no vibrato, no need for the two 220k mixing resistors, just the 500k MV just before the cap to PI, my question was is a 220k needed before the MV, l guess it would keep the PI from overloading..?
HBP, I hear ya but if l was to put a MV  in right before the PI, using the 220k before the master, should it not be used..

[pdf64]

if no vibrato, make your MV the intensity pot, maybe 500k and move the tie point right of the 220k, maybe

That’s pretty much what DrZ does with the EZG50.
There’s little to no preamp overdrive available, but it’s handy to be able to set the preamp vol to get the action of its bright cap where you want it.
I guess a switchable bright cap would make even that benefit questionable 

[shooter]

I'm in HBP N PDF64's corner on "why", that said, I'd wire it as a Voltage divider (220k) - 500k pot and prove us wrong 
(you can always gatorclip the 220k, or || another 200k)  15 min of fun, 30 min figuring out what to keep

[6v6Pin1]

If you never dime the MV, I would skip the 220k. If you do, I would keep it.

This is a good article on the circuit you are describing: https://robrobinette.com/RR763_BLACKVIBE.htm

[Joel]

I've built this one:  https://el34world.com/Hoffman/files/Hoffman_AB763_1.pdf

As I understand it, in the Single channel version a 47k resistor (R30) was used to simulate the load of the normal channel and tremolo.  I replaced the 47k R30 with a 1M pot as the Master Volume.  I think this amp works well as a MV amp.  If I ever open it up again I'll be reducing the 1M pot to something like a 47k resistor + 250k pot though (along with a LND150 style Trem-O-Nator).  It definitely sounds better if the current 1M MV is set at 7 or 8.  Any higher than 8 and I don't really like the sound of the distortion.  So, yeah, as suggested above a divider is probably a good idea but there is a lot of scope to play with the values.

[dude]

I had skipped the 220k, with MV dimmed or almost,  the distortion isn’t to my liking. Now l see why.  6v6, thanks for that link, next time l open the amp, l’ll make the correct changes. Thanks for all the replies.