giovedì 29 novembre 2018


The multicassa is an electronic instrument composed of 3 cassa (bass drum) generators controlled by an analog trautonium like rhythms generator.
The term trautonico is inspired by a vintage instrument, the Mixturtrautonium, invented by Oskar Sala musician, a student of Hindemith, which elaborate it, since the 30s on the basis of another instrument more simple, the Heimtrautonium, manufactured by Telefunken in the '20s, one of the first electronic instruments for the living room.

Early versions of Mixturtrautonium use as frequency dividers the Thyratron(a type of gas valve that could be used to build oscillators and frequency dividers), these dividers acting on the notes producing subharmonic that could be mixed (hence MIXTUR) for produce complex sounds, the same principle is used here with two differences:
- The valves are replaced by solid-state trigger circuits.
- Dividers act not to the notes but on the rhythms, by dividing a basic rhythm (clock) for a variable number (with the command Clock Divider) rhythms are then mixed 2 by 2 (Trig Mix) generating a complex poly rhythms.
- An output mixer allows you to adjust the volume of each speaker.

Each cassa has a pitch, resonance and distortion control.
The clock can be generated internally or applied externally through jack on the left side of the unit.
The multicassa accepts any type of clock pulse or square wave of 3-12 volts amplitude, with any polarity including the Midi clock, as long as the midi line is present only midi clock and no other messages (notes, control changes, sysex, etc.) .

FREQUENCY: Adjusts the pitch of the sound of the case, also affects the resonance.
RESONANCE: Adjusts the resonance, ie the damping time of the case.
Beyond a certain level the cassa go into permanent oscillation. The level at which the oscillation begins varies with frequency.
DISTORSION: Adjusts the level of signal distortion of cassa.
TRIG MIX : The rhythm played by each cassa is the sum of the rhythms generated by the two dividers that are located under the cassa. For example, the cassa 1 plays the rhythms of DIVI1 if trig mix pot. is all to the left, of DIVI2 if all to the right or a mix in between.
CLK DIVIDER : These set the clock divisor, ie how many clock pulses (white LED)it takes to get a shot of cash (colored LEDs). If the potentiometer all the way left, to each pulse of the white LEDwill have a shot (divisor 1), slowly moving forward we will have dividers more and more high (shots more and more slow). The max divider is about 64 (potentiometer fully right).
TEMPO: In internal clock mode adjusts the speed of the basic clock, and then all of the rhythms. All on the left, minimum speed, maximum speed all right.
When you are on the external clock the tempo pot. acts as a divider (clock prescaler) in the same way of the clock divider, in this case the we will have the maximum speed with the tempo potentiometer all at the left dividing by 1.

OUT: Multicassa have an internal mixer, the mixed channel is sent to the mix out connector, there is also individual out of the tree channel, when use individual out keep the mix out volume pot to 0.

TRIG OUT: The trim mix 2 and 3 is sent to trig out connectors.


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