Passive Bandpass Octave Filter - Herzlich Gabor - 10hp Eurorack filter - B&K 1613 style filter

PLEASE NOTE: This device has been discontinued. I happen to have two units left which were returned, and as such I will not be selling them as brand new, although they are in perfect condition and freshly serviced. Please read the description, possibilities and limitations of the Gabor carefully, and perhaps check out the demo video. The items are sold "as described" as they are returns, and as such are not "fresh from the workshop" any longer. In turn, the price is also lower. Thank you in advance for your understanding!

In recent years, passive octave bandpass filters have gained popularity due to their inherent utility in sound design, but supply has been limited to old laboratory equipment which has become increasingly difficult to find.

As a consequence, I designed and made the Herzlich Gabor, with inspiration from the function of the Brüel & Kjær 1613 passive bandpass filter, but in Eurorack format.

The filter comes with a handy chart indicating the octave bands for each position of the rotary switch, which is particularly nice and clicky. The components are high precision, and styrene capacitors add the finishing touch of high quality to this filter. The function is NOT identical to the B&K unit, but similar, and adapted for use in Eurorack systems.

The filter works particularly well with feedback, complex waveforms, amplification and distortion - as it is passive, no amplification or feedback is made within the circuit, but using mixer channels and VCAs it's easy to create beautiful, grimy, squeaky and sometimes interesting patches and glasslike oscillations from feedback. The downside is that the filter significantly drops volume of input signals, especially those that are not harmonically rich. The filter also works well when applied to full mixes, by carving out certain octave bands for processing, sidechaining, mixing or enhancement.

Do note that the unusual nature of the filter makes it unsuitable as a "normal" filter - you will have to patch it creatively, drive it hard with amplification, use it as a slew limiter. Some customers have described it as the kind of device you can patch with for hours, exploring feedback and complex waveforms mangled and tamed, and a few didn't enjoy it so much. That's fine, the Labs can't please everyone, but now you've been adequately warned ;)

Every filter is hand built in my workshop in Copenhagen, Denmark.

Dimensions: 10hp wide, 19mm deep. Skiff friendly!