X-Series MKII Backend Filter

24dB/octave VCF/VCA with envelopes

Think of Macbeth's Backend Filter as a classic subtractive analog synth without the oscillator section. It consists of an audio mixer, a low-pass filter with four different outputs, two envelopes and a VCA. Except for one IC, the module is completely discrete, which guarantees vintage sound

New features to the predecessor:

-use of very high-quality parts throughout the signal path. Significant improvement in the choice of capacitors.

-In addition to the 16-pin Doepfer standard connector for the power supply, the rarely used CV bus has now been used. On the Backend Filter not only the CV busses but also the gate connector was installed. Both can be switched on or off discretely at the back of the unit(s).

-In addition to this Backend Filter, an external discrete amplifier with 200x gain is now used, which is accessed via a two-function jack. The small control potentiometer and the jack socket are normalized to the output of the second VCA, and in this configuration the main output can be fed back to the input amplifier of the filter, thus achieving a "saturated overload".

-Throughout the Backend Filter, a mixture of selected 'passive' components and precision-matched transistors provides a particularly warm filtered sound.

-The jack sockets have been redesigned. In the original X-Series, Ken Macbeth used the same type of 'box jack' that many others use. Ken began to question the reliability of this type of plug - and now with the MK2 versions about to be launched, he felt it was important to upgrade the jacks to a higher quality type. As far as plugging is concerned, they will have a much longer life, which in turn will increase reliability."