Kurzweil K250 User manual

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Kurzweil250
SERVICE MANUAL
(K250, K250X and RMX Models)
Kurzweil Music Systems, Inc.
411 Waverley Oaks Road
Waltham, MA 02154
[phone]
January, 1989
Document No.: 92000201

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CHAPTER 1
CHAPTER 2
CHAPTER 3
CHAPTER 4
CHAPTERS
CHAPTER 6
CHAPTER 7
Table of Contents
INTRODUCTION
PRODUCT HISTORY
SYSTEM OVERVIEW
DIAGNOSTICS
DISASSEMBL Y/ASSEMBL Y PROCEDURES
PARTS LISTS
SCHEMATICS, LAYOUTS, WIRING DIAGRAMS
KURZWEIL MUSIC SYSTEMS, INC.
411 WAVERLY OAKS ROAD
WALTHAM, MA 021S4
DOCUMENT PART NO. 92000201
January, 1989
Kurzweil Music Systems, Inc.
The information contained herein is confidential and proprietary to Kurzweil Music
Systems, Inc. It
is disclosed to you solely for purposes of instruction as to operation of
the equipment and maintenpnce as appropriate. It is not to be used by you for any other
purpose, nor is it to
be disclosed to others without the express permission of Kurzweil
Music Systems, Inc.
Kurzwell 250 Service Manual
i

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Chapter 1 - Introduction
1.1 Product Description
1.2 Specifications
1
.2.1 Kurzweil 250
1.2.2 Kurzweil 250X
1.2.3 KurzweiI 250 RMX and 225 RMX
1.3 How the Kurzweil 250 Works
1.3.1 Masters Section
1.3.2 Assignments Section
1.3.3 Selection Section
1.3.4 Program Section
1.3.5 Media Section
1.3.6 Back Panel
Kurzweil 250 Service Manual, Chapter 1
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1-2
1-3
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1-4
1-5
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1-6
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1-7
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1.1 -PRODUCT DESCRIPTION
The Kurzweil 250 uses artificial intelligence principles and a
Motorola 68000 microprocessor to create complex models of
acoustic sounds. The Kurzweil 250's design gives the instrument a
velocity-sensitive keyboard so that a
note's volume· and timbre
relates to the force
on the key. The 12-note, polyphonic keyboard
can accurately reproduce the sounds of several instruments
at once
and each key
on the 88 note keyboard can be individually assigned to
play a different sound.
Currently, the Kurzweil 250 comes with 36 different
instruments arranged into 98 keyboard setups in the basic Enhanced
Resident Sound Block excluding Sound Blocks A thorugh
D. The
original Kurzweil 250 came with 30 different instruments arranged
into
40 keyboard setups.
The Kurzweil
250's sequencer is a built-in, 12,OOO-note
multi-track digital recorder, which can be used to build up to 12
different tracks. Older Kurzweil 250's may have either 4,000 or
8,000 note sequencer. These units can be updated to the current
12,000 with the purchase of available options.
All Kurzweil 250s are currently manufactured with the
Kurzweil Sound Modeling Program for user sampling. Older Kurzweil
250s may not have this option, but may be updated with the purchase
of the Sound Modeling Program option.
There are many configurations
of Kurzweil 250s currently in
the field. The Kurzweil 250 Product Line also includes the Kurzweil
250X, an expander unit without keyboard, and the Kurzweil RMX 250
or 225, a rack mount expander unit. Please see the Product History,
Chapter 2, for more information.
Kurzwell 250 Service Manual, Chapter 1
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1.2 -SPECIFICATIONS
1.2.1 - Kurzweil 250
Keyboard: 88 keys with velocity-sensing and piano action.
Pedals: 2, assignable piano-type in the POD, 2, external
volume-type
Dimensions (Cabinet): 56"(L) X 27"(W) X 9"(H)
Dimensions (POD): 22"(L) X 11 "(W) X 4.5"(H)
Weight (Cabinet): 95 Ibs.
Weight (POD): 22 Ibs.
Power Consumption: 110/220 VAC, 50/60Hz, 380 watts
max.
Operating Conditions: 0 to 50
0C Ambient 20 to
80%
Relative Humidity
Storage Conditions: -25 to 1250C,10 to 90% Relative
Humidity
Audio Outputs: High level, Low level, Balanced, Stereo
headphones
External I/O: High-speed parallel computer port, MIDI In,
MIDI Out and MIDI Thru ports, Sync In, Sync Out, Trigger In,
Click Out, MIC, Line In, 2 External volume-type pedals,
cartridge slot
1.2.2 - Kurzweil 250X
Dimensions (Cabinet): 49 1/2" (L) X 20 1/2" (W) X 6
3/4"(H)
Dimensions (POD): 22"(L) X 11"(W) X 4.5"(H)
Weight (Cabinet): 45 Ibs.
Weight (POD): 22 Ibs.
Power Consumption: 110/220 VAC, 50/60Hz, 380 watts
max.
Operating Conditions: 0 to 50
0C Ambient
20 to 80%
Relative Humidity
Storage Conditions: -25 to 1250C,10 to 900/0 Relative
Humidity
Audio Outputs: High level, Low level, Balanced, Stereo
headphones 1
External I/O: High-speed parallel computer port, MIDI In,
MIDI Out and MIDI Thru ports, Sync In, Sync Out, Trigger In,
Click Out, MIC, Line
In, 2 External volume-type pedals
Kurzwell 250 ServiceManual, Chapter 1
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1.2.3 - Kurzweil 250 RMX AND 225 RMX
Dimensions (Cabinet): 19" (L) X 22" (W) X 10 1/2"(H)
Weight (Cabinet): 53 Ibs. r
Power Consumption: 110/220 VAC, 50/60Hz, 380 watts
max.
Operating Conditions: 0 to 50
0C Ambient 20 to
800/0
Relative Humidity
Storage Conditions: -25 to 1250 C,1 0 to 90% Relative
Humidity
Audio Outputs: High level, Low level, Balanced, Stereo
headphones
External I/O: High-speed parallel computer port, MIDI In,
MIDI Out and MIDI Thru ports, Sync
In, Sync Out, Trigger In,
Click Out, MIC, Line
In, 2 External volume-type pedals
Kurzwell 250 ServiceManual, Chapter 1
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1.3 -HOW THE KURZWEIL 250 WORKS
This section describes briefly how the Kurzweil 250 controls
work. Refer to the Kurzweil 250 rUser's Guide for more detailed
information. Since this is a complex instrument, always confirm
that a problem truly exists before attempting to· service the
instrument.
1.3.1 - Masters Section
The group of slider controls in the Masters section controls the
overall sounds that the instrument makes.
TUN E - Use this slider control to control the overall pitch of
all active voices.
INSTRUMENT GROUPS A & B - These two sliders move two
different, assignable instrument groups from left to right in
the stereo image.
VOlUM E - This controls overall volume.
1.3.2 - Assignments Section
This section of the Front Panel controls are used primarily
during live performance.
Each of the three vertical sliders can
be assigned to control one
of approximately
20 different functions such as tremolo, pitch bend,
vibrato, legato, attack, decay and sustain. By using these controls,
you can simulate a wide variety of playing techniques, including a
full variety of synthetic effects.
Musicians can also assign the foot pedals and Mod
levers using
switches
in this section.
Kurzwell 250 Service Manual, Chapter 1
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1.3.3 - Selection Section
The Selection area on the Front Panel contains the switches
that allow users to control the main r functions of the system. With
the LCD display, they tell what operating mode' the instrument is
in
and allow the musician to make changes and answer questions.
SPLIT KEYBOARD -This is another control used at per-
formance time. It allows you
to assign a certain section of
the keyboard temporarily to a certain instrument.
CHORUS -When you press this button, you can turn one sound
into many. The "Chorus" capability can be used for doubling,
built-in echo and flanging.
SELECTION SWITCHES -The YES, NO and SELECT switches are
used to choose options and answer questions displayed
on the
LCD.
NUMERIC KEYPAD -Use the numeric keypad to enter choices
and
to select functions (with the "F" switch).
1.3.4 - Program Section
This group of controls, along with the numeric keypad, allow
you to program the Kurzweil 250. These controls are generally used
for setup before a performance.
CURSOR KEYS -The cross shaped group of keys below PLAY are
the cursor controls. The center key (R) is for resetting when
you have made a mistake or want to return to the initial cursor
placement.
S
EQU ENCER - The Kurzweil 250's sequencer is a built-in,
12,000 -note multi-track digital recorder. You can use it to lay
down one instrument and then play a second instrument on top
of it.
By repeating this process, you can build up to 12 diff-
erent tracks.
Other keys in this section speed up or slow down the tempo of a
piece, modulate
to another key, change modes or edit keyboards,
instruments or sequences.
Kurzwell 250 ServiceManual, Chapter 1
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1.3.5 - Media Section
The Media section lets you program, store and recall your own
set of keyboard setups, instruments and .sequences.
LIST -This key allows you to run through, in any order, every
keyboard setup stored
in the Kurzweil 250's memory. You can
reprogram this list to meet you own performance needs. You
can also list sequences using this switch.
STORAGE - The Storage READ switch is used to prepare the
instrument to use a cartridge.
In future versions of the in-
strument, the STORAGE switches will be used with external
media options.
1.3.6 - Back Panel
The back panel contains all the input/output connections for the
Kurzweil 250.
COMPUTER -This is the parallel computer port for attaching a
personal computer
to the Kurzweil 250.
TRIGGER
IN -The Trigger In is a TTL-compatible input used for
starting a sequence from
an external device. The sequence
triggers
on the positive edge of the supplied pulse. Minimum
pulse width
is 1 microsecond. The input impedance is greater
than 10k ohms. The trigger level
is 2 volts. This I/O port takes
a 1/4 inch phone jack.
CLICK OUT -The Click Out is a TTL-level output pulse. When
enabled from the Front Panel, a positive pulse appears at this
output. Its repetition rate
is the selected sequencer tempo.
Driving source
is a low power TTL gate through a 51 ohm resis-
tor. This I/O port takes a 1/4 inch phone jack.
SYNC IN -The Sync In is a TTL-compatible input used to drive
the Kurzweil 250 from another instrument. The other instru-
ment
is to provIde a square wave at X12 to X96 the tempo. The
input impedance
is greater than 10K ohms. The trigger level is
2 volts and this I/O port takes a 1/4 inch phone jack.
Kurzwell 250 Service Manual, Chapter 1
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SYNC OUT -The Sync Out is a TTL-level square wave. output
used to drive other instruments
in synchrony with the Kurzweil
250. The repetition rate is normally X12 to X96 the tempo. The
driving source is a low powerr TTL gate through a
51 ohm
resistor. This I/O port takes a 1/4 inch phone jack.
MIDI IN -This is a 31.2K baud, 5 milliamp serial input.
MIDI THRU -This is a 31.2K baud, 5 milliamp serial output.
MIDI OUT -This is a 31.2K baud, 5 milliamp serial output, the
same
as MIDI IN buffered.
LO -These are 2 VPP audio outputs, with a 600 ohm driving
source impedance. These require 1/4 inch phone jacks and are
suitable for line level inputs.
ill -These are 20 VPP audio outputs, with a 600 ohm driving
source impedance. These require 1/4 inch phone jacks and are
suitable for directly driving power amplifiers and other high
level
inputs.
BALANCED -These are 20 VPP audio outputs. They have XLR
connectors, floating outputs and a 600 ohm driving source
impedance.
EXTERNAL PEDALS 1 & 2 - The 1/4 inch phone jacks accept
assignable pedal functions (K250 and K250X only).
M.lQ. -This digitizer input is a 200 mVPP full scale input. It
has a 47K ohm input impedance and accepts a 1/4 inch phone
jack.
LINE IN -This digitizer input is a 1 VPP full scale input (300
MV rms.) It has a 10K ohm input impedance and accepts a 1/4
inch phone jack.
Kurzweil 250 Service Manual, Chapter 1
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