Crossfader

Passive crossfader

The CF is a passive crossfader module. It does not have bleed at the extremes like other passive crossfaders. It is ideal for attenuating, mixing or crossfading audio signals (not as ideal for precision voltages). The max amplitude output will be about half the strength of the original signal. If you're using unbuffered audio sources, there can be a slight dip in amplitude at the extremes.

Since it is passive, it can also be used in reverse to mix two audio signals.

https://store.synthrotek.com/Crossfader_c_223.html