Another common pattern is jack + offset. The most useful is when you have jack + offset + attenuator… but most modules pick one or the other for space reasons.

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robotresearcher 5 months ago | parent | next [-]

The attenuator-inverter is super handy too. A gain knob that goes from -1 to +1 X.

	▲	wbl 5 months ago \| parent [-]
		That's a neat trick. Only way I can think of to do it involves two op amp buffers, one inverting one not and take the signal from the wiper.

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BlandDuck 5 months ago | parent | prev | next [-]

Totally. Also, an attenuator is easier and cheaper to implement, because it just requires normalizing V+ into the jack plug. An offset requires an adder.

My preference is: attenuator < offset < attenuator + offset. I see no benefit of having to remove the knob to get to the jack as proposed in the article.

	▲	nine_k 5 months ago \| parent [-]
		The benefit is saving space. Imagine a 10x10 grid of such jack / knob inputs.

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lsaferite 5 months ago | parent | prev [-]

There are dual-knob coaxial setups that are only slightly bigger than a single knob as well. I've seen them mainly used in a course and fine adjustment setup, but you could certainly use them as atten+offset.