The first large diaphragm condensers all used vacuum tube amplifier technology. Many of those early models became classics. Just mentioning a model such as the famous Neumann U47 (the holy grail of LDs) makes any sound engineer salivate.The fact that tube condensers are still produced today is not just sentimental reminiscence for good old times. Tube microphones cultivate this kind of larger-than-life sound that LD condensers are famous for. The soft distortion characteristics of tube circuits help to bring out harmonics that make the signal appear more interesting, more engaging, more present. However, this sexy sound wouldnt be right for all tracks in the mix. Signals that are not featured but only have a supporting function (and those signals are important, too!) better appear more sober, more laid-back, so the featured sources stand out. Tube or solid state (often termed FET for field effect transistor), therefore, is not a question of good or bad but of application, and any decent recording studio uses both tube and solid state condensers, depending on purpose.