am i reading thsi correct

[trem]

http://el34world.com/charts/Schemati...cert_ii_83.pdf

Into Jack 2, both "switches" are lifted and the 2x 68k make a 50/50 divider into a parallel V1.?

Into Jack 1 the same 68k are parallel, and they see that 1M resistor, so not much loss.?
But...Jack 2 is shorted.....Tip to Sleeve.....and that involves those two diodes under V2b.?
Can somebody explain these two Channels/Tone Stacks, and those diodes.?
Thank You

[52 Bill]

Into Jack 2, both "switches" are lifted and the 2x 68k make a 50/50 divider into a parallel V1.?

The basic input scheme here is the same as most Fender amps. When plugged into #2, the signal goes through a single 68K resistor and is shunted to ground via the second 68K resistor and the 1 Meg resistor. When plugged into the #1 jack, the two 68K resistors are paralleled so the signal sees 34K resistance with 1 meg shunted to ground. When both jacks are used, each signal sees 68K resistance and each input is also isolated from each other by 136K.

So when #1 is used alone there is less signal loss than when #2 is used alone. When two instruments are plugged into both jacks each instrument is isolated from each other so that when one guitar turns down its' volume control, the second guitar does not turn off as well.

But...Jack 2 is shorted.....Tip to Sleeve.....and that involves those two diodes under V2b.?

There is no tip to sleeve connection here. Each of the two jacks has a second set of switches that control the channel switching function. That is what the two diodes under V2b are for.

The signal is amplified by V1 which has both halves paralleled so that it can drive two separate tone stacks, one for the clean channel and one for the dirty channel. Then there are photocell switches that select which channel is sent to the output. I haven't back traced the switching circuit, but I would guess that with nothing plugged into the amp, the channel switch is automatically set to clean.

[The Dude]

No dig intended, but I just have to point out the humor in:

"am i reading thsi correct"

[Enzo]

Their you go againg.

[trem]

OK...Gotcha. The schem, with two switches on the jack makes it look like (to me) Number 2 shorts the tip and sleeve.
Thank You so much for the explanation.
Yes, I Know.....I spelled Tulip incorrectly in the title.

[Enzo]

That dual vertical line between upper and lower contacts on the jack is not an electrical conection, it is a representation of the insulated "lifter" that actuates the extra contacts. When you plug in, the tip contact is raised, and a plastic spacer on the tip contact pushes against the extra contacts to "lift" them. The lower pair of contacts in each jack is not electrically connected to the signal input or the tube.

[trem]

Hey Enzo -
I guess I need to actually Look At one of those jacks if possible. Are they (most likely) a plastic cased affair, and hard to see, if you know what I mean..... Compared to a Switchcraft jack where you can see all the switching that goes on.?
But I do get what you are saying. The vertical lines you mention, I was misinterpreting THAT as the sleeve.....but the sleeve comes first, and is (clearly) visible on the schem.
I guess I chose not to see it for some reason. My Mistake.

[g1]

#13 here should be similar to what Enzo mentioned.

[trem]

Ahh...OK...Great.
I see it now...Thank You