MFB Bass 522 - Drum Manual

General

The module Bass-522 is basically composed of the circuit of the MFB-522 Bass Drum but its sound can be wider edited. Beyond that, the module allows a control of the four sound parameters – sound, decay, tune and pitch through the CV signals like envelope curves, LFOs and Step Sequencers.

Operation

The type and the electricity supply of the module Bass-522 is compatible with the Doepfer A100 modular system. The ten-pin MFB connection cable is connected with the 16 pin jack of the MIDI/CV board or the Doepfer bus-board. The supply voltage has to total up to +/- 12 volt. A 5 volt voltage is not necessary. The wattage is +/- 30 mA. The module width amounts to 8 HP = 40 mm.

Attention: You have to make sure that there is the correct polarity! The coloured wire of the ribbon cable has to look down, that means the cable is not allowed to be twisted.

Functions

The Bass Drum is actuated by the In jack. There can be used an analogue or a digital gate signal of a step sequencer, MIDI-CV/Gate transformer or a square wave LFO. There can be used drum pads, piezos or dynamic microphones alternatively. Dynamic trigger affect pitch and decay next to the attack and volume. With the help of the trim regulator Sens are you able to adjust the input sensibility to the trigger signal. The highest trigger voltage should be not more than 0,1 volt. The input reacts to the positive edge of the trigger signal. The audio signal is taken from the jack Out and will be carried to a mixer, (DRUM -99 for example), VCA or any other sound editing modules. This output can be connected directly to a mixer or an audio interface.

Sound parameter

The frequency will be adjusted with the pot Tune, whose range lies with 35 Hz and 60Hz. The frequency can be controlled with any CV signal through the input Tune. The pot works as an attenuator in this case.
The Pitch controls the length of a concrete adjusted Pitch Envelope typical for TR-909 or Simmons bass drums. This can be modulated via Pitch - CV input, in this mode the regulator works as attenuator too.

Decay sets the release time of the bass tone up to one second. The Decay CV In let control the time via CV, the regulator works as attenuator as well.

Ton filters the attack transient and noise source. Via internal jumper you can choose CV In will controls Ton or Noise.

Noise adds the volume of white noise (decay differs with decay settings of the bass tone). Via internal jumper you can choose CV In will controls Ton or Noise.

Note: The required voltage for all CV-inputs needs to be within a range of 0 to 5 volts.

The module offers the new developed M-Bus connector whats mean you can you control everything via Midi/CV interface or our SEQ-01 Pro drum sequencer without additional patching. Modules get connected serial, M-Bus to first module, first module to second module and so far. Following addresses are supported:

Trigger MIDI Note #35 oder #36, depend to the jumpers position, with velocity.

MIDI Controller values for
Tune = 17 Pitch = 25
Decay = 33
Ton = 41
Noise = 49
Noise Decay = 57

Controllers getting ignored if another bass module is triggered. For bass drum modules Midi Notes #33, #34, #35 und #36 are reserved. Once the Bass-522 reserved trigger appears again the module reacts to CC again.

Note: The value of controller will be added to the pots.