Filtek MK3

Filtek MK3 EQ Plugin GUI

Filtek MK3

3-Band EQ / HPF / LPF

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The plug-in emulation of the hardware Filtek MK3 unit is powered by the Synergy Core built-in DSP acceleration. Monitor with the effect in real-time when recording or use it when mixing or mastering in your DAW without adding any CPU load.

Originally designed in the 70’s, the FILTEK MK3 is a highly successful creation. That’s no wonder as the unit was built to the rigorous standards demanded by the IRT (Institut für Rundfunk Technik). Initially costly to build and within reach of only the most reputable radio stations, these broadcast-ready modules eventually ended up inside the racks of recording studios around the globe.

A versatile equalizer which sounds clear and precise – unusually modern for the time, indeed – the MK3 handles broad sweeps and surgical applications with equal aplomb. The combinations of controls and switches allow for plenty of experimentation. For example, extreme settings at broad bandwidths turn the high and low bands into respectable shelving filters.

The efficient design, employing the best engineering practices and high-quality parts, proves the MK3 capable of not just correcting, but also enhancing frequency ranges – for example, boosting the high-end without introducing harshness.

For the Synergy Core FX platform, Antelope’s team of engineers modeled the 3-band design with high- and low-pass filters – perhaps the most recognizable and also flexible incarnation of FILTEK MK3’s incarnations. Each band offers a choice of 12 frequencies with boosts and cuts of up to 16dB. The three-way bandwidth (Q) switches for each band let you bypass specific bands when in mid-position.

Filtek MK3 also delivers unique tonal shaping possibilities when its Parallel EQ signal path allows to mix the unprocessed (dry) signal with the additional cut/boost of each bell filter frequency range

Clean and transparent, but packing plenty of punch and character when pushed, the FILTEK MK3 is an incredible addition to your frequency adjustment toolbox!


• Versatile 3-band equalizer with modeled transformer-based input and output sections
• Unique signal path allowing for parallel equalization by mixing boosted/attenuated signal with unprocessed audio
• Monitor and record without latency when processed by Antelope’s Synergy Core DSP acceleration engine
• Each band offers a choice of 12 frequencies with +/-16dB of stepped gain and a 3-way Q-switch
• Q-switches in mid-position bypass frequency bands
• Wide-ranging low- and high-pass filters
• Bypass switch for the entire module
• Output peak meter


Simply insert the FILTEK MK3 into your FX chain. Click and turn the per-band knobs and switches to make the desired adjustments. Feel free to push the input signal (within reasonable limits) to obtain transformer saturation.