The 655C is a dynamic omnidirectional microphone that can be very useful for a number of live sound applications. This microphone was intended to be used in professional broadcast/studio environments so it is quite rugged and built with the quality that one would expect from Electro Voice microphones of this era. One drawback for modern utilization of this mic is that it uses the obsolete Cannon UA-3-11 connector, which looks similar to a standard XLR but is oddly shaped like the letter D. These connectors were also used on other early EV mics including the model 666.
So here's the scoop on the sound quality of the 655C. For starters it has a very wide, flat, and directional frequency response making it ideal for multiple source recordings. Since it is a omnidirectional microphone it produces minimal proximity boost for close mic placement, but it also exhibits some lo-fidelity when you get less directional from the source. When pointed directly and placed closely to a source it can be quite soft and detailed. When placed at a distance or off axis it sounds very colored starting in the upper frequencies as you lose directionality. It is a versatile and 'old school' sounding mic that can be utilized in a few different ways. I consider it the most ribbon sounding dynamic I own. I have had some good luck with it on guitar cabs, especially since it produces an even and unhyped characteristic making it really pleasant for everything from clean to raging guitar amp settings. I have also used it as a mono room mic for drums which is always fun! This mic also retains an impressive frequency response when distant miking.