Savvas, if the noisy/vibrating motor is effectively decoupled from the arm/platter combination it will only affect the sound if you can hear it from your listening position. The Studer A 80 motor im using, is because of its shear size and friction of solid sintered bronze bearings on large steel shaft somewhat of a noise-maker, and vibrations are at certain frequencies like the putter of a Dodge Viper idling But the sound is phenomenal ! And vibrations and noise can not be heard at my listening position, or with needle in the groove with ear close to the speakers. Only one time where i had inadvertently let the phono cable touch the test motor housing did it translate into noise from the speakers.The ‘no character’ and ‘no sound ‘ are expressions that have been abused since long time ago
I wonder how, a ‘no character Tonearm ‘ remains with ‘no character’, if for example the tt motor is producing resonances and noise which is audible from over 2 meters away, or how a Tonearm with built-in stepper motors, industrial wires‘ management system , etc has ‘no sound‘ and ‘no character‘
This discussion in my opinion underlines the importance of measurements in manufacturing. Measurements are fundamental for the final product which is the listening.
I am not saying that bad measurements necessarily mean bad sound, but certainly they are translated into a colored sound, which can be pleasant for many. Elevated mechanical noise or resonances can negatively affect some frequencies and color pleasantly some others.
In any case the sound experience is subjective but at least with objective measurements in place , the listener will know how much colored is the sound he is getting; and will not live in an illusion of ‘no character’ or ‘no sound’