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Midi Clock (MC)
MC in form is essentially a midi click sent at a specific tempo. The rate or speed (Beats per minute or BPM) of the click determines the speed at which the synchronised units run together. The master unit in the chain will run on its own internal clock and provide the master MC signal to the slave units. Note that any midi product capable of sending MC will automatically do so if its Midi Clock setting is set to Internal or (INT). The slave units are to required to synchronise to the clock signal (MC) provided by the master unit. This can be achieved by setting the slave units to run on external clock (EXT), which refers to the incoming Midi Clock signal provided by the master, and is generally an option found within the Global or System menu screens. The next step is to connect the Midi out of the ‘master’ to the Midi in of the ‘slave’ via a Midi cable or lead.
Since Midi Clock operates around tempo, its general display time is in Beats per Minute, or BPM. As a result, MC can easily be used to display in bars and beats by specifying the timing signature (e.g.4/4), which is particularly useful from the perspective of musicians.
A typical application wherein Midi Clock becomes necessary is when trying to get a sequencer (or workstation) to synchronise to either an external drum machine or groove box, or even to sync up the arpeggiator of a synth so that they run in time with one another. Note that generally within any sequencer, software or hardware, there is a master or tempo track that can also be programmed by the user to facilitate tempo changes within a particular song at specific intervals.
For reference, most synthesizers, drum machines and sequencers are capable of generating and accepting Midi Clock. However, certain caution needs to be exercised around entry-level software sequencers (e.g. Steinberg Cubase SE3 & Pro Tools LE) which do not support any type of synchronisation.
Midi Time Code (MTC)
MTC is a linear time code displayed in absolute time, e.g. hours, minutes, seconds and frames. As a result, particularly from a composition perspective, MTC can be viewed as a little awkward since its time base cannot display in bars and beats. Note that musicians tend to function around bar numbers and movements (e.g. intro, chorus, and bridge) when recording not specific time intervals.
Also, MTC and MC are not inter-changeable and to my knowledge there has never been and will never be a product capable of converting from MTC to MC, or vice versa, since they are two completely independent and unrelated timing protocols.
A typical application of MTC is slaving a digital recording desk, e.g. a Yamaha 02R96, to a Digital Audio Workstation (DAW), say a computer based Pro Tools or Cubase recording set-up for synchronising mixing automation to recorded audio.
Note: MMC (Midi Machine Control) is not to be confused with the above, since MMC refers to specific Midi commands not synchronisation, e.g. Stop, Play, Record, Rew & FF. For example, within a Mackie D8B (digital desk with automation) HDR2496 (24 track recorder) system, the user by pressing ‘play’ on the desk initiates the MMC command for play, which instructs the HDR2496 to play. The HDR2496, which generates MTC, then starts to play and in turn fires MTC at the desk. The desk, if set correctly, slaves to and runs in time to this incoming time code. As a result, any automation commands input into the desk are locked to the appropriate point in recorded
men mpc2000 slavede van MTC en zende MC ook uit,maar of dat die dat tegelijk deed weet ik nu ni meer...