Tone stack question

[Gone_Fishing]

Can someone explain to a "rookie" like me, the first channel tone stack on a Bassman Ten.  I can't recall seeing this anywhere else, like the .1 cap instead of a slope resistor and others. I pretty much understand the second channel (like most all BF and SF Fender amps).  Thanks in advance.  Eual

[tubenit]

Compare the Fender Bassman 10 tone stack to the DanElectro Centurian 275 tone stack.  See similarities?

http://el34world.com/charts/Schematics/files/danelectro/danelectro_centurian_275.pdf

http://el34world.com/charts/Schematics/files/fender/Fender_bassman_10_schem.pdf

I don't know if I am remembering correctly, but I think this might be a T-filter tone stack.  Maybe HotBluePlates or Sluckey can chime in?

With respect, Tubenit

[HotBluePlates]

... I think this might be a T-filter tone stack.  ...

Good job! That's exactly what it is!

Can someone explain to a "rookie" like me, the first channel tone stack on a Bassman Ten.  ...

Have you ever seen a graph of the response of the typical Fender tone stack? Overall it passes lows and highs but cuts mids. And then you can vary the three ranges.

The Treble control is connected to a T-filter, which makes a broad notch like the typical Fender tone stack. Except the values of the individual parts are sized to place this notch up in the treble range. Increasing resistance to ground (by way of the Treble control) reduces the depth of the notch.

The Bass control is simpler than it looks. With the Bass pot wiper towards the bottom, only the top 0.022uF cap is in the circuit, and sets a bass roll-off like every other coupling cap. When you turn the Bass control to max, a second 0.022uF cap is in parallel with the first, doubling the effective coupling cap value. That moves the bass roll-off downward, which sounds like added bass.

[Gone_Fishing]

Thanks gentlemen,,,,that helps me