Paralleling PI output coupling caps with a switch

[Helmholtz]

I understand what you mean.
But only IMD can produce a real additional difference frequency.
Those IMD products are typically non-musical.
As a beat or difference frequency requires two frequencies, it's not a subharmonic.

BTW, it's a myth that lower frequencies "contain" more power.
The power formula P = V*I is not frequency-dependent.

[Chuck H]

BTW, it's a myth that lower frequencies "contain" more power.
The power formula P = V*I is not frequency-dependent.

Right. Thanks for the clarity. Stuck in my head is something I read (I think we all did) indicating that it takes more power to produce low frequencies. My logical mind knows that there are caveats with the Fletcher Munson curve and specifcs of amplitude. Relative to perception but not electronics or power.

[g1]

But still, power spent on unneeded LF is wasted power, and takes away from what's available for more relevant content, does it not?

[Chuck H]

But still, power spent on unneeded LF is wasted power, and takes away from what's available for more relevant content, does it not?

That had occurred to me but I let it go.

[Helmholtz]

But still, power spent on unneeded LF is wasted power, and takes away from what's available for more relevant content, does it not?

A spectrogram of the (distorted) output signal would reveal if there's significant LF content below 82Hz.
With an AC30 I doubt it.
Nevertheless an AC30 can be somewhat bass-heavy (depending on speakers), especially when placed on the floor.

But let the OP's ears decide.

[Chuck H]

But let the OP's ears decide.

Right? I'm sure they're all about it but since seven isn't here I'll just mention that any of us could have wired it up (with switches) many times over in the time this discussion has taken

[Helmholtz]

I think the OP's question has long been answered.

[g1]

I'm just here because you guys give good chat.

[seven]

Yup, I'm good. Carry on, though, if need be.

[mozz]

Playing a g chord, 2 lowest notes, won't you get the sum and difference, that would be lower than 82hz?

[Helmholtz]

Playing a g chord, 2 lowest notes, won't you get the sum and difference, that would be lower than 82hz?

Only if there's IM distortion - not with a linear amp.

[mozz]

You have HD, you have IMD.
Stolen from the web.

"So, IMD creates non-harmonic tones, tones that do not lie in the chord, and that sounds bad. One other note: IMD tones are actually higher in magnitude than HD tones. Theoretically, IMD-2 tones are 6.021 dB higher than HD-2 tones, and IMD-3 tones are 9.542 dB above the corresponding HD-3 tones. Adding insult to injury… This is another reason IMD is more important than HD in the real world.
"

[Helmholtz]

You have HD, you have IMD.

Yes, question is how much in relation to fundamentals.
A little IMD may actually enhance the sound of a guitar amp.

These days many players even like to boost bass in the power amp via a "resonance" control.

[Tom Phillips]

Playing a g chord, 2 lowest notes, won't you get the sum and difference, that would be lower than 82hz?

Theoretically yes. However, the results depend on the intermodulation distortion level of the circuit.