The AKG C 28 A is a small diaphragm tube condenser microphone. This predecessor to the C 451 has preamp circuitry which is similar to the C 12 and AKG-built ELA M 251E microphones, with 6072 tube, T14 output transformer and N 12 power supply.

While typically sold with CK 28 cardioid capsule, an optional omnidirectional capsule (CK 26) was available as an option and can be quickly swapped with the cardioid capsule thanks to a modular design. Pricing here reflects the preamp body with either of these capsules.

The C 29 A and 30 A are the same mic electrically, but with a "gooseneck" attachment for the capsule to make the microphone less obtrusive and easier to implement in live television broadcasts.