Worth noting that that round knob, where it exists, has lost a lot of functionality:

1. Setting volume to 0 will pause the recording, even though I sometimes want to silently forward through some unwanted parts (intros or ads in podcasts).

2. These knobs are also infinity knobs, I liked to have fixed start and end position with an indicator how loud it's going to be when I switch on. That last part has been taken over by software and probably can't be done reliably any more.

3. On the leftmost, zero position that round knob was also used to switch a radio on or off. It is very convenient to have a single movement to switch music on, and with the same movement adjust the volume, or to lower the volume and while doing so, maybe decide to switch it all off entirely.