Korg music workstation How Sampling mode is organized, 100, Sampling frequency and bit resolution

• The waveform can be viewed in the LCD screen, and

edited by a variety of waveform editing commands

that include rate convert (down-sampling) and reverse

playback.

• Start, loop start, and end addresses can be specified in

units of a single sample. Loop tune, reverse playback,

and loop lock functions are also supported.

• The Use Zero function automatically searches for

zero-cross points, making it easy to find the beginning

or end of the waveform, or locations that will not

produce noise when the sample is played back.

• The grid function displays a BPM-based grid on the

waveform display, helping you to create loops or

make waveform edits that match the desired BPM.

How Sampling mode is organized

This section describes how sampling on the TRITON STU- DIO is organized. (☞see the lower diagram on the follow- ing page)

Sampling frequency and bit resolution

As shown in the diagram, sampling reads the level of the analog signal at fixed intervals along the time axis, and stores the levels in memory as digital data.

• Each multisample allows you to create up to 128

indices. Each index consists of a sample assignment, a

key zone, an original key, a playback pitch, and

settings such as level.

• The “Keyboard & Index” display lets you edit a

multisample while viewing the assignments and zones

of each sample.

• Sample names and multisample names of up to 16

characters can be assigned. Sample names and

multisample names can also be viewed in Disk mode

(☞PG p.157 “Translation”).

• The Time Slice function automatically detects the

attack portions of a kick or snare etc. in a rhythm loop

sample (a looped pattern of drums etc.), and divides it

into separate rhythm instrument sounds. A pattern

Level

Analog waveform

Level

Sampled digital waveform

Time

48kHz

= 48,000 times every second = 0.0208 mS cycle

16bit

Time = 65,536 levels of data

corresponding to the divided samples is created

automatically, so that you can immediately use the

Sequencer mode RPPR function to play the pattern

and adjust the tempo without changing the pitch. You

can also do things such as adjusting the pitch of only

the snare, replacing it with a different sample, or

changing the playback timing on the sequencer, in this

way creating a new rhythm loop based on the rhythm

loop you started with. (Stereo samples are supported.)

• The Time Stretch function lets you modify the tempo

without changing the pitch of a sample. You can select

either Sustaining (suitable for sustain-type

instruments such as strings or vocals), or Slice

(suitable for rhythm loops on decay-type instruments

such drums). Stereo samples are supported.

• The Crossfade Loop function is an important looping

tool that helps smooth out irregularities in long loops

which contain complex material. By executing

Crossfade Loop, you can eliminate this problem and

create natural-sounding loops.

• The Link (with Crossfade) function allows you to join

two samples into a single sample. You can also

crossfade the overlapping portion of the samples at

this time, so that the volume changes gradually,

producing a natural-sounding transition.

• The BPM Adjust function (playback pitch adjust) lets

you adjust the playback pitch of each index so that the

loop frequency matches the desired BPM value.

• You can use resampling (auto) to automatically apply

effects to a sample and create a new sample.

The “fixed intervals” mentioned above are generally expressed as the “sampling frequency.” 48 kHz (kilohertz) means that sampling is performed 48,000 times each sec- ond, and that the interval is 1 (second)/48,000 (times) = approximately 0.00002083 (seconds) = approximately 0.02083 mS (millisecond).

The higher the sampling frequency is, the closer to the original analog signal the waveform in memory will be.

Each level is read, and converted into digital data. The accuracy at this time is determined by the bit resolution. This process converts an analog signal with infinite reso- lution into a digital signal with finite resolution. With 16 bit resolution, each level is indicated in 65,536 steps (the sixteenth power of two).

The greater the bit resolution is, the closer to the original analog signal the waveform in memory will be.

48 kHz 16 bit sampling is the same quality as in audio devices such as DAT. A CD uses 44.1 kHz 16 bit sampling, which is a slightly lower sampling frequency.

100