All five bands of the TM105 equalizer have identical boost/cut ranges of +/- 20 dB. The TM105 is also available with +/- 12 dB range. Apart from the sweep range, the three fully parametric bands are identical. Each band has a boost cut control, a q-factor control and a frequency control. The filters are based on adt-audio's active 'Vienna-Bridge' principle that allows independent control of all parameters and wide control ranges. The actual 'Vienna Bridge' determines the center frequency as integrated part of an active filter circuit that has been improved for many years. The tonal characteristic of these equalizers comes very close to the performance of passive L/C based filters but without the limitations of these circuit that offer only small variation options and need huge inductors for low frequency processing. The Vienna bridge circuits maintain natural sound performance in a 'musical' way, even with drastic settings.

The three fully parametric Bands of the TM105 5 Band Equalizers cover the entire audio band from 20 Hz to 25 kHz. Due to the extensive sweep range of 1 : 100 per band, the frequency ranges have huge overlaps. In the range from 60 Hz to 7 kHz two of the three bands can be used; the range from 250 Hz to 2 kHz is possible for all bands. This offers the opportunity to use one band for a global correction with wide q-factor setting while another band is used in the same frequency range to support formants or suppress interfering frequencies. The fully parametric low band MID1 ranges from 20 Hz to 2 kHz, the MID2 band has a sweep range from 60 Hz to 7 kHz. The fully parametric high band MID3 can be tuned from 250 Hz to 25 kHz beyond the upper limit of the audio band. Using this high frequencies with an appropriate q-factor results in soft and silky highs.

The q-factor control range is identical for all fully parametric bands and reaches from 3 octaves down to a third. Soft and global settings are possible as well as precise fine tuning of small frequency bands.

The three fully parametric bands are completed by a high - low equalizer, based on soft RC filters with 6 dB steepness and low phase shift.

A set with two switches allows the selection of four different characteristics for the High EQ. The default characteristic is a shelving filter with an edge frequency beyond the audio band. This setting is well suited for corrections at the upper limit of the audio band and produces silky sounding highs when boosting. It can also reduce harshness and similar side effects of digital audio processing by settings that cut away 1, 2 or even 3 dB. The two switches alter the characteristic of the high eq to a very soft bell. The combination of the switches determines the weakly pronounced center frequency of 12, 8 or 4 kHz. Extensive processing options for all kinds of global high frequency treatment are available. Due to the soft characteristic of the filter and the power bandwidth of more than 100 kHz, all settings are free from distortion and any other kind of side effects.

The Low Equalizer is a soft bell, also based on an RC filter with 6 dB steepness. 2 switches determine the center frequency that can be set to 40 Hz, 60 Hz, 100 Hz and 160 Hz. The soft bell characteristic avoids subsonic interferences when boosting low frequencies, as they are usual with common Baxandall high-low eq's. Actually, the low eq of the TM105 Equalizer operates like a combination of a shelving low eq with a high-pass filter that limits boosting the subsonic range. However, the very important phase response of the soft bell eq is a lot better than the phase response with shelving eq and high-pass filter.

High EQ and Low Eq are designed for global corrections while the three fully parametric bands are well suited for complex equalizations.

The entire equalizer has + 30 dBu headroom and 120 dB dynamic range. The RMS noise is less than - 90 dBu with linear settings.

The TM105 Equalizer is a 4U ToolMod module that can be used in two adjacent slots of a 1U high ToolMod Frame or in a 4U high ToolMod Frame. Versions with +/- 20 dB and +/- 12 dB control range are available as well as vertical and horizontal versions.