The maximum Gain is 70 dB; ribbon microphones with very low output level can be used without problems. The lowest gain setting is 24 dB; high level condenser microphones can be used without pad. The mic input can be used with line level signals if the 24 dB input pad is switched on. The headroom with pad is + 30 dBu. The attenuation circuit is entirely switched out to avoid additional load on the input when the pad is off. A switch activates the 48 volts phantom power supply.

The Noise Performance of the TM101 Mic Pre is very close to a 'wire with amplification'. At maximum gain of 70 dB, the noise figure is better than 1.6 dB. This means, that the total noise at the amplifier output is 1.6 dB higher than the noise of the source resistance of a typical microphone, which is 200 ohms. Much more important is the noise performance at lower gains that are commonly used. The TM101 is optimized for this range; the typical noise figure is 1.3 dB at 50 dB gain and remains below 2 dB down to 40 dB gain.

The Input CMRR is better than 70 dB up to a frequency of 15 kHz; typical values are: 15 kHz - 75 dB, 1 kHz - 93.8 dB, 40 Hz - 103 dB. The input impedance is higher than 2 kOhms in the frequency range from 20 Hz to 20 kHz. Well-balanced, soft RF filters maintain a power bandwidth of more than 100 kHz and an extremely flat phase response but provide effective protection against RF interference and the intermodulation effects caused by parasitic autooscillation. The Frequency Response is flat from 30 Hz to 20 kHz. The low frequency phase response, which is crucial for the sound performance at the low end of the audio band remains below 10° down to 30 Hz, even though a soft subsonic filter protects the amplifier against impact noise and infrasonic interferences.

The additional, electronically balanced Line-Input is totally separated from the microphone input and has its own input amplifier and its own gain pot with +/- 20 dB range. The input impedance is higher 10 kOhms; the headroom is more than + 30 dBu. This input is selected by the LINE switch.

The Phase Reversal Switch operates on both inputs.

The High-pass Low-pass Filter is inserted by the FILT switch. The sweep ranges are from less than 20 Hz to 600 Hz for the high-pass filter and from more than 20 kHz down to 2 kHz for the low pass filter. The steepness of the high-pass filter is 24 dB/oct, the low-pass filter has a steepness of 12 dB/oct. Both are active, maximum flat filters.

The Level Indicator displays the actual output level on a multicolor LED using different colors. With green color the level is above - 20 dB. The color changes to yellow at 0 dB and turns to orange and red when the level raises. The remaining headroom with red color more than 5 dB.

The electronically balanced output can handle levels of more than + 30 dBu. The source resistance is lower than 50 ohms in the frequency band 20 Hz to 20 kHz. THD remains below 0.1 % up to output levels of more than + 28 dBu.

The TM101 mic pre is a 2U ToolMod modules. It fits in all ToolMod frames. Horizontal and vertical versions are available.