The TLM 103 condenser microphone uses a capsule based on the K87 capsule. This is the same capsule used in the famed Neumann U-87 and tube U-67 microphones. The K103 capsule features an acoustically balanced sound with very good rejection of sound coming from the rear of the mic. The transformerless circuit within the TLM 103 has very low self-noise (7dBa) and a very large dynamic range (131dB SPL). The TLM 103 will withstand sound levels up to 138 dB SPL which is nearly the sound level of the exhaust of a modern fighter jet in full afterburner.

The TLM 103 has response down to 5 Hz and so Neumann has employed an elastically mounted internal structure to reduce the influence of external shocks on the sound of the mic. Sonically, the mic has been compared to the U-87 and so has a similar presence boost in the higher frequencies. Neumann has elected to offer this mic in a single polar pattern (cardioid), without an attenuator switch (because you don't need it...if your mic pre can take it) and without a bass roll-off. This is all to help keep the mic under $1,000 and still maintain Neumann quality.