At Superbooth 2022 Doepfer presented 3 new eurorack modules: A-121, A-138j and A-183-5
Module A-121s is a dual multimode filter which can be used for stereo applications as well as for parallel or serial organized dual mono filters. The core is a 12dB multimode filter identical to the modules A-121-2 and A-121-3. The selection of the filter type is continuously from lowpass via notch and highpass to bandpass. We attached great importance to the usability of the manual controls and CV inputs for both stereo and dual mono applications. For the filter parameters frequency (F), resonance (Q) and type (T) common controls and CV inputs as well as single controls and CV inputs are available. For the filter frequency in addition a manual control and CV input for the filter spread (frequency difference or delta F) is available.
Module A-138j is a four channel mixer with an additional polarity/mute switch for each input. In the upper position of the corresponding switch the inverted signal is used. In the center position the input in question is turned off (mute) and in the lower position the “normal” (i.e. non-inverted) signal is used. The inverting of signals is used especially for control voltage signals (e.g. LFO, ADSR). But even for corellated audio signals this feature is useful. For example for feedback applications or the mixing of original and processed signals (e.g. original and filtered signal to obtain new filter types).
Channel 1 features in addition an Offset function: provided that no plug is inserted into socket Input 1 control Lev.1 generates an adjustable DC voltage (positive or negative depending upon the position of the polarity switch).
On top of that the module is equipped with two types of single outputs and a dual mix output. All inputs and outputs are DC coupled. Consequently the VCAs can be used to mix both audio and control voltages.
Each input is – apart from the polarity/mute switch – equipped with a linear attenuator. The amplification range is 0….1.
Module A-183-5 is a simple passive quad attenuator. Passive means in this context, that each unit is made of two sockets and a 50k linear potentiometer only. There are no active parts like amplifiers or buffers and no power supply is required.
This is how the A-183-5 works: At the output socket appears the attenuated input signal, i.e. zero level at the fully CCW position and max. level and the fully CW position.
More info here: Doepfer