The remote control of the EAR-Yoshino 868 works just as @larryi describes: a motor manually moves the volume knob, affecting the sound of the pre-amp in no way. The remote's only other control is a mute button. Volume and mute are the only two functions I require from the remote of a pre-amp.
Does remote control degrade the sound of tube preamps?
Some preamp manufactures (e.g. CAT) don’t put remote controls in their preamps due to the supposed sound degradation. This could also be just an excuse. Do you think the sound quality is degraded with a remote? I am talking about an audible effect.