I found the following excerpt from a very comprehensive article on the Sweetwater website about:
Neumann Microphones Buying Guide
I hope you enjoy the whole article when you get around to it. But in the mean time …
What Do Neumann’s Badge Colors Indicate?
You’ll notice that every Neumann microphone proudly displays the Neumann badge, but you’ll also notice a variety of badge colors. What do they mean? The badge color identifies the type of internal signal path utilized by that microphone. Neumann has developed a number of different microphone designs over the years, and the badge color tells you which design your microphone uses.
Black: Tube
You’ll find the black diamond on Neumann’s tube microphones such as the legendary U47, M49, and U67. The tube amplifier stage can add complex harmonics that enhance the overall richness of your recording. When engineers talk about warm, vintage tone, it’s often a classic tube microphone they’re describing.
Purple: FET 80 + Transformer
As solid-state microphone technology advanced, Neumann created mics with a FET amp stage with an output transformer. FET-based mics don’t generate the additional harmonic content that tubes can, resulting in “cleaner” recordings with more precise sound. This design also allows for smaller overall size than tube microphones require.
Red: FET 100 + No Transformer
Neumann’s transformerless microphones employ a FET amp stage, with a transformerless output circuit that reduces self noise and can make the microphone’s overall response more accurate. While recording engineers love the character of transformer-based mics, there are many applications in which the additional transparency and accuracy of a transformerless mic are desired.
Blue: Digital
Neumann was the first microphone manufacturer to develop mics with a digital output stage, designated by the blue badge. These mics employ an A/D converter and DSP processor directly after the mic capsule, with an AES 42 digital output that allows for very long cable runs with no additional noise. Neumann’s digital microphones boast amazing dynamic range and fidelity, making them a top choice for orchestral recordings.
Green: Dynamic
With so many famous condenser microphones to their name, it’s easy to forget that Neumann makes an exceptional dynamic microphone that’s widely used in broadcast. The BCM 705 dynamic mic captures radio-ready sound with the exceptional ruggedness and SPL handling you look for in a dynamic microphone.
Credit:
https://www.sweetwater.com/insync/neumann-microphones-buying-guide/
