Bright Cap Alternative?

[dwinstonwood]

Hello all, is there any reason why this wouldn't work, or is a bad idea?

There should be no DC on the switch. A 4.7M resistor could be put across the switch to prevent pops (like with an AC15-style tone switch).

It would result in a 0.011 coupling cap. Not as dramatic as a conventional "pF" bright cap, but it could cut some lower frequencies, which could be good when using heavier distortion. Different cap values could be tried to find the best effect.

Thanks!
David

[Merlin]

It will work, but you can do it even better by not totally breaking the signal path with the switch. The switch can simply short-out the cap when not needed. This is a useful trick to avoid pops when switching coupling caps! (It also means you can use a SPST switch, if you want)

[dwinstonwood]

Thank you Merlin! I'm going to give your way a try.

My recent 5693 SE project sounds great (full, warm) at cleaner settings, but I think I can get tighter "articulation" when cranking up the gain by having smaller coupling caps.

David

[Merlin]

My recent 5693 SE project sounds great (full, warm) at cleaner settings, but I think I can get tighter "articulation" when cranking up the gain by having smaller coupling caps.

Even with both caps in circuit you will have 11nF of capacitance, which still covers the entire audio range. You may find it more useful to make the second cap even smaller, like less than 10nF. You're basically doing what Orange did with their 6-way switch!
https://schematicheaven.net/newamps/orange_graphic_mkii_or120.pdf

[dwinstonwood]

Thanks! That's kind of what I'm using in my AC15. I could always add more than just one cap.

[dwinstonwood]

Well, since I've already done this very thing, I have no idea why I asked in the first place. Getting old?