Hardware & signal path
MIDI
MIDI is the control language a controller speaks. It carries note and control-change messages rather than audio, each with a value from 0 to 127, which is how a knob movement becomes a parameter change in software.
In practice
A standard MIDI control has 128 steps across its whole travel, which is why some faders feel coarse.
When a pitch or filter control feels steppy, check whether the software offers a high-resolution mode for that control — several send two messages per movement to get far finer steps, and it is often off by default. Beyond that, MIDI carries clock as well as control, so a controller or a drum machine can share tempo with your software over the same cable; and because the protocol is generic, an old controller and new software will talk to each other as soon as you map them, regardless of what shipped in the box.
0–127
Values in a standard message
Notes and CC
What buttons and knobs send
Clock
What carries tempo
Where these come from: Properties of the MIDI protocol itself, not catalog figures. For what we can measure, see assigning those messages to functions.
Why it matters
The 0-to-127 part explains something people notice and misattribute. A standard MIDI control has 128 positions across its whole travel, so a MIDI pitch fader is coarser than a dedicated player’s — the fader is fine; the resolution of the message is the limit.
It also means the connection is generic. Any MIDI controller can drive any MIDI-capable software once mapped, which is why a discontinued unit stays useful long after its bundled software has been abandoned.
Frequently asked
Does MIDI carry audio?+
No. It carries control messages only — which button was pressed, how far a knob moved. The audio travels separately, through the controller’s soundcard or an audio interface.
Why does my MIDI fader feel steppy?+
A standard MIDI message has 128 values across the full travel. Some software supports a high-resolution mode that sends far finer steps; it is usually a per-control setting and off by default.
Can any controller work with any software?+
Usually yes, once mapped. MIDI is a generic protocol, so an unsupported or discontinued controller stays usable long after its bundled software stops being updated.
Related terms
MIDI mapping
MIDI mapping assigns a physical control to a software function. Most software has a learn mode: arm mapping, move the knob, click the function, and that control drives it until you change it again.
Controller
A controller is a jog-wheel-and-mixer surface that drives DJ software on a computer. It sends control messages rather than making playback decisions, and usually carries the soundcard that turns the software’s output back into sound.
Audio interface
An audio interface converts between the digital signal inside software and the analogue signal a mixer or amplifier accepts. In a timecode rig it also converts the other way, digitising the control signal coming off the turntables.
Sync
Sync matches one deck’s tempo to the other automatically and holds it there, using the beatgrid the software calculated. It removes the arithmetic of beatmatching, not the decision about which record follows which.
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