Appendix E Dictionary Of Selected Terms - Alesis QS Series Service Manual

10.00 Appendix E Dictionary Of Selected Terms

48KHz Normally running at 48Khz, however, this usually is in reference to the system
sample rate clock and may change to accommodate variable pitch..
A.K.A. Also Known As
Alias An unwanted byproduct of digital audio, aliasing really describes two separate
phenomenon. Amplitude aliasing occurs due to the fact that digital audio is not
smooth, but stored as a series of quantized values. Without output filtering the
signal, each subsequent change to a new quantized level (which occurs very
rapidly) would in itself add an unwanted component to the original audio material.
The second type of aliasing is frequency aliasing. While the reasons for this
(Nyquist Theory) is beyond the scope of this manual, it is sufficient to say that care
is also taken to ensure that digital signals from the system don't leak out through
the audio output.. While not audible, these signals could play havoc with other
digital devices further along in the audio chain..
ASIC Application Specific Integrated Circuit
Aux Auxiliary Output
Crash An unfortunate consequence of the digital age, it is a complete system shutdown.
This can be due either incorrect software values or faulty hardware. This can be
one of the most difficult types of problems to troubleshoot.
D-A Digital to Analog conversion.
DAC Digital .to Analog Converter
DRAM Dynamic Random Access Memory
EPROM Erasable Programmable Read Only Memory
FX Effects Generator
GAL Gate Array Logic
H8 The Hitachi H8/510 microprocessor.
I/O Input/Output
LFO Low Frequency Oscillator
MAC Macintosh computer.
Mapped I/O A digital circuit type that allows a microprocessor to access external hardware
functions through unused memory locations.
MIDI Musical Instruments Digital Interface. A manufacturer's standard for data
communications between different musical instruments types, as well as providing
an interface between instruments and computers.
Optical In this case it is a reference to the Alesis ADAT fiber optic buss. Designed by
Alesis for the ADAT Recording System, this interface allows multiple channels of
digital audio to be transmitted and received for unparalleled sonic quality. Note
that as audio sources, the QS Series only uses a digital optical out.
P4 The current generation of Alesis 35 Watt in line transformers.
Alesis QS Series Keyboards Service Manual V1.00 83 11/19/06