Just replace it. A new stylus is about $60 for the Audio-Technica. Cheap insurance. There is really no way -- aside from gross mistracking -- for someone without a microscope and experience to effectively evaluate the condition of a stylus. Besides, even if the stylus is fine, the suspension bits may be dried up and damaged. A new stylus unit insures against both possibilities.
Your Proton has a pretty good phono stage. Like NAD stuff, it can sound a bit 'dark.' So, provided your speakers aren't overly bright, I would go with the Audio-Technica AT120E you already have or the Ortofon 2M. Both have detailed enough treble to counteract the preamp's tendencies.
Your Proton has a pretty good phono stage. Like NAD stuff, it can sound a bit 'dark.' So, provided your speakers aren't overly bright, I would go with the Audio-Technica AT120E you already have or the Ortofon 2M. Both have detailed enough treble to counteract the preamp's tendencies.