AB763 Bandmaster Skyliner Tonestack Help

[martin manning]

To turn the Rock stack schematic I posted above into Jazz, disconnect the bottom of the treble pot from the top of the bass pot, and disconnect the bass pot wiper. Add a 5n cap to ground from the bottom of the treble pot, and a 100k from the bass pot wiper to the treble pot wiper.

[Jake1524]

Hey Martin, thanks for this. Attached is what I’ve drawn up so far. It is not complete as I cannot quite wrap my head around how to wire the 100k resistor in the fashion you’ve explained.

[martin manning]

You were almost there. That's the 100k in red. As mentioned above, if you use an On-Off-On switch, you have Preamp Boost in the middle position.

[Jake1524]

You were almost there. That's the 100k in red. As mentioned above, if you use an On-Off-On switch, you have Preamp Boost in the middle position.

Martin, ive finally gotten around to doing this as live got pretty busy for a bit there. I have to say the difference here is astonishing! The amp is so clear without being harsh or strident like a normal fender.

Couple caveats.. I’m having to run the treble at 10 to get enough high end and the bass at 0 as there is still a bit too much woof for me.

I assume I should start by cutting bass cap from .1 to .047 and maybe increasing treble cap? What do you think?

Thanks again for all your help, can’t tell ya how stoked I am!

[martin manning]

Cutting the bass cap in half will reduce the very low frequencies, so yes give that a try, or try the usual remedy of reducing the PI coupling caps.
You could increase the treble cap, but maybe look for other places where highs are cut, like the input grid stoppers, or maybe find a brighter sounding tube for V1.