Reflex Lexicon User manual

Reflex Service Manual
Table of Contents
1.
Reflex Controls and Connectors
Front Panel 1-1
Storing and Clearing Registers
Rear Panel 1-2
Footswitches •MIDI OUT/THRU Jumper
Setting Audio Levels 1-3
Periodic Maintenance 1-3
Ordering parts 1-3
Returning units for service 1-4
2.
Specifications
3. Performance Verification
Block Diagram 3-1
Required Equipment 3-1
Initial Inspection 3-2
Functional Tests 3-3
Listening Tests 3-5
Diagnostics 3-6
Power Up Diagnostics •User Diagnostics
Audio Performance 3-14
Disassembly/Reassembly 3-17
Troubleshooting Tree 3-18
4. Theory of Operation
Analog and Converter Circuitry 4-1
SAH •DAC •Deglitch (Output Hold) •Output Circuitry
Reset, System Processor, Memory Mapping,
Interrupt Timer •Power Fail/Reset
Z80, ROM, RAM, Memory Map 4-4
NMI/ Circuit (Interrupt Timer 4-5
NMI Behavior on Power Up •INT/CKT (MIDI IN)
Front Panel, Fotswitches, MIDI I/O, EEPROM 4-6
I/O Registers •O/P Registers •EEPROM 64kbits
(8k X8), 24C65 Interface •Software Requirements
Anote on the electrical interface for the EEPROM
data I/O •I/P Registers •MIDI I/O
Lexichip II, DRAM, Clocks 4-10
DAC/ADC Control Logic and Data Port
Power Supply 4-11
5. Parts List
6. Schematics and Assembly Drawings

Controls the proportion of processed
(wet) to unprocessed (dry) signals
sent to the outputs.
INPUT
Sets the level of the incoming
signal. —Status LED is off
when the incoming signal is
too low (<~30dB). Acceptable
levels are indicated by green
(-30 to -1 2dB) and orange (-
12to -6dB). The LED lights
red to indicate overload (-6 to
OdB). I
OUTPUT
Controls Reflex output level.
DISPLAY
+=store function enabled
-=clear function enabled
1-128 =ID number of currently running
effect or parameter setting
•=Edit indicator or patch Indicator
depending on mode of operation
LEDs= currently selected parameter
The Front Panel
PARAMETEP/LEARN
Selects DECAY, DELAYor FX LVL
for adjustment with VALUE
knob. Holding sets Reflex to the
same MIDI channel as aconnected
device, and activates patch assign-
ment.
VALUE
Adjusts value of selected param-
eter. Display of parameter values is
indicated by flashing of the selected
parameter LED.
STORE C+)/CLEAR <-)
The STORE/CLEAR button selects
Reflex's readiness to store an effect or to
clear aregister. These states are indi-
cated by a+(store) or -(clear) symbol in
the display.
REGISTER/PRESET '
Button selects preset or register mode.
LED lights when register mode is selected,
turns off in preset mode.
Knob will select presets 1-16 or registers
1-128, depending on button setting.
To store or clear the currently running effect...
1.Briefly press STORE/CLEAR to display “+” or depending on whether
you want to store or clear aregister.
2. Press and hold STORE/CLEAR. If you were in preset mode, the register
LED will go on, indicating that Alex has automatically switched to register
mode —selecting whatever register is being pointed to by the PRESET
REGISTER knob. The +or- symbol in the display willflash, indicating that
the store or clear function is armed.
3. Releasing STORE/CLEAR with aflashing +displayed, will store the
currently running effect into the register indicated on the display, ovenwrit-
ing the effect previously stored there. The display will flash briefly to
indicate the store operation was successful.
Releasing STORE/CLEAR with aflashing -displayed, will clear the
contents of the displayed register. The display will flash briefly to indicate
the clear was successful. (The ID number of cleared registers flash when
selected with the PRESET/REGISTER knob.)
To restore acleared register, simply repeat the clear operation.
Storing and Clearing
Reigsters
Store and clear operations are executed on release of the STORE/CLEAR button. If you
want to store to or clear adifferent register than the one displayed, turn the PRESET/
REGISTER knob to the register number you want before releasing STORE/CLEAR.

Controls and Connectors Lexicon
The Rear Panel Audio connections to Reflex are unbalanced and should be made with high
quality shielded cables with 1/4" tip-sleeve phone jacks at the Reflex end.
Reflex produces stereo effects from either mono or stereo sources. With
mono sources th edry signal appears in mono at both output connectors along
with the stereo effects. For instruments and sources with stereo outputs, use
both inputs. We recommend using the outputs in stereo whenever possible,
but if mono output is required, you can use either output connector. The left
and right signals are summed internally when only one output is used.
Footswltches afootswitch connected via the rear-panel footswitch jack allows you to
perform register step and/or bypass functions. Two momentary footswitch es
can be wired to atip-ring-sleeve connector. Astereo Y-connector allows two
identical single switches to be used.
When shipped. Reflex is configured to use momentary switches. You can
change this configuration to allow the use of latching switches by performing
the following procedure:
1. Simultaneously press the PARAMETER/LEARN and the REGISTER/
PRESET buttons. This will put the unit into Advanced Programming
Mode (lighting all 3front panel parameter LEDs).
2. Turn the REGISTER/PRESET knob to 15. The letter "F" should appear
on the display.
3. Turn the VALUE knob to select 0(latching) or 1(momentary).
4. Press the REGISTER/PRESET button to restore normal front panel
operation.
MIDI OUT/THRU Jumper when shipped. Reflex is configured for MIDI OUT operation. You can
reconfigure the unit for MIDI THRU operation with the following procedure.
1.Disconnect power.
2. Remove the two top and bottom cover screws which are closest to the
rear panel MIDI connectors.
3. Lay the unit upside down and remove the rack ear.
4. Lift the jumper off of its pi ns and reposition it accordi ng to the functionality
you want.
5. Replace the rack ear and the cover screws.
6. Reconnect power.
1-2

Reflex Service Manual Controls and Connectors
1. Turn Reflex's INPUT and OUTPUT controls all the way down (fully
counter-clockwise).
2. Connect Reflex inputs to an audio source, and Reflex outputs to an
amplifier or mixer.
3. Apply an input signal at alevel that you typically use.
4. While sending audio to Reflex, gradually turn upthe INPUTcontrol until the
Input Status Indicator lights green. Continue to advance INPUT until the
LED shows red on only the loudest peaks. If the LED shows red continu-
ously, turn the INPUT control down.
5. If Reflex is using aconsole’s sends and returns, set the MIX control fully
clockwise (100% wet). If you are using an instrument amplifier, start with
MIX set halfway up.
6. Gradually increase the setting of the OUTPUT control until the audio level
from the amplifier or mixer is approximately the same as when Reflex is
bypassed.
Under normal conditions Reflex requires minimal maintenance. Use asoft,
lint-free cloth slightly dampened with warm water and amild detergent to
clean the exterior surfaces of the unit.
Do not use alcohol, benzene or acetone-based cleaners or any strong
commercial cleaners.
Avoid using abrasive materials such as steel wool or metal polish. If the unit
is exposed to adusty environment, avacuum or tow-pressure blower may be
used to remove dust from the unit's exterior.
When ordering parts, identify each part by type, value and Lexicon Part
Number. Replacement parts can be ordered from:
Lexicon, Inc.
100 Beaver Street
Waltham MA 02154
Telephone: [phone]
Fax (Customer Service): 617-788-0499
ATT:Customer Service
MIDI OUT/THRU Jumper
Setting Audio
Levels
Periodic
Maintenance
Ordering Parts
1-3

Controls and Connectors Lexicon
R©turning units Before returning aunit, for warranty or non-warranty service, consult
for SGrvice with Lexicon to determine the extent of the problem, and to obtain
Return Authorization. No equipment will be accepted without Return
Authorization from Lexicon.
If you choose to return aReflex to Lexicon for service, Lexicon assumes no
responsibility for the unit in shipment from customer to the factory, whether
the unit is in or out of warranty. All shipments must be well packed (using the
original packing materials if possible), properly insured, and consigned to a
reliable shipping agent.
When returning aunit for service, please include the following information;
•Name
•Company name
•Street address
•City, State, Zip Code, Country
•Telephone number (including Area Code)
•Serial number of unit
•Description of the problem
•Preferred method of return shipment
•Return Authorization #, both inside and outside of package
Please enclose abrief note describing conversations with Lexicon personnel
and give the name and telephone number of the person directly responsible
for maintaining the unit.
Do not include accessories such as manuals, cables, footswitches, etc.
with the unit, unless specifically requested to do so by Lexicon Service
personnel.
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Audio Inputs (2)
Level -30dBu minimum
Impedance stereo/50 kQ unbalanced
mono/25 kQ unbalanced
Audio Outputs (2)
Level -2dBu nominal
+8dBu maximum
Impedance 75Q. unbalanced
Muting reduces transients during power on/off
Footswitch Connectors
T/R/S phone jack for bypass and register step
MIDI Connectors
5-pin DIN connectors for MIDI IN and MIDI OUT or THRU
(selectable via internal jumper)
Frequency response
Wet 20Hz-15kHz, -r1dB to -3dB
Dry 20Hz-20kHz, ±0.5dB
THD+N Wet <0.05% @1kHz
Dry <0.025% @1kHz
Dynamic Range
85dB, typical,
20Hz-20kHz bandwidth
Conversion
16 bit linear PCM encoding; 31.25kHz sampling rate
Power Requirements
9VAC, 1Awail transformer provided
Dimensions
19"Wx 1.75"Hx4"D
(483 X45 X102mm)
Weight
2lbs 11oz (1 .22 kg)
Environment
Operating
Temperature 32° to 104°F (0° to 40° C)
Storage -20° to 170°F (-30° to 75° C)
Relative
Humidity 95% non-condensing
Specifications subject to change without notice.
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Required Equipment
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Clean, antistatic, well lit work area
Variac, 1amp minimum
Double footswitch (Lex #750-09365 or equivalent)
MIDI cable (1 ft. minimum)
Low Distortion Sine Wave Audio Oscillator
THD+N Distortion Analyzer
Stereo headphones
Two (2) audio cables unbalanced and shielded with 1/4" phone plug on
one end and the appropriate connection on the other end to connect to
the Audio Oscillator output and Distortion Analyzer input
Yconnector for connecting the audio cables to the oscillator
9VAC power supply (Lexicon #470-09650)
3-1

Performance Verification Lexicon
initial Inspection
Power Up
1.Inspect the unit for any obvious signs of physical damage.
2. Verify that all front panel knobs operate smoothly and freely.
3. Verify that all screws and rear panel jacks are secure and inspect the AC
power supply for any sign of physical damage.
4. Turn the REGISTER/PRESET knob, to select 16RESONATOR.
5. Turn VALUE to the 6:00 position.
AC Current
1.Set the Variac to OVAC minimum.
2. Connect the OVAC power supply to the isolated variable output of the
Variac.
3. Connect the OVAC power supply to the power input on Reflex.
4. Slowly increase Variac to 120VAC.
5. Verify the AC current draw is <0.12 Amps.
On normal power up, Reflex will run the following tests:
Display Test
ROM Test
SRAM Test
WCS Test (Writable Control Store)
Interrupt Test
On normal power up, all display segments except for the decimal point, and
all LEDs except for the headroom LED, light for about 2seconds. This is
followed by the display of Lfor approximately 7seconds, after which the
display will indicate the current position of the REGISTER/PRESET knob. In
this case, +16 should be displayed with the DECAY LED lit.
NVS Inititialization
1. Power cycle Reflex while pressing and holding STORE/CLEAR and
PARAMETER/LEARN.
2. After 3or 4seconds, verify that the letter dappears on the display, then
release the buttons.
3. Press and hold the REGISTER/PRESET button until the display goes
blank, then release the button.
4. Press the REGISTER/PRESET button and verify the display reads: 15.
5. Pressthe REGISTER/PRESETbuttonand verifythatthe+symbolflashes
momentarily, and is followed by a display of: 15.
6. Turn the REGISTER/PRESET knob counterclockwise to point to 10Drum
Plate. The display should read: 9.
7. Press the REGISTER/PRESET button, and verify that the display reads:
1.This display will flickerfor approximately 18seconds, following which an
Lwill be displayed for approximately 7seconds. After this, the display will
read: +10 (the current position of the REGISTER/PRESET knob)
.
8. TumtheREGISTER/PRESETknobclockwisetoselect 13 CHORUS. The
display should read 13.
3-2

Reflex Service Manual Performance Verification
Display
1.Powercycle Reflex and verify that all display segments except the decimal
point, and all LEDs except for the headroom LED, light for approximately
2seconds. This is followed bythe display of Lfor approximately 7seconds,
after which the display will indicate the current position of the REGISTER/
PRESET knob. In this case, +13 should be displayed.
2. Power off Reflex.
Connections
1. Using the 15 foot 1/4" phone plug cable supplied with the footswitch,
connect one end to the footswitch and the other end to the Reflex rear
panel FOOTSWITCH (Bypass/Step) jack.
2. Connect the MIDI cable between the Reflex rear panel MIDI IN and MIDI
OUT/THRU jacks.
Encoders
1. Power on Reflex while pressing and holding STORE/CLEAR and PA-
RAMETER/LEARN.
2. After 3or 4seconds, verify that the letter dappears on the display, then
release the buttons.
3. Press and hold the REGISTER/PRESET button until the display goes
blank. The display should read: 12.
4. Press STORE/CLEAR to enter the test. Verify that the display becomes
dim and that the display reads: -C.
5. Turn the REGISTER/PRESET knob to its 6:00 position and verify that the
display reads +0.
6. Turn the REGISTER/PRESET knob clockwise one position, and turn
VALUE clockwise one position. The display should read: +1
.
7. Reset each knobto the remai ning 14positions and verify that the +symbol
is displayedwhen both knobs are in the same position. The display should
also indicate the current encoder positions in hexadecimal.
NOTE: When the knobs are in different positions, the -symbol will be
displayed along with the current position of the REGISTER/PRESET knob (0-
15). When the knobs are in matching positions, the -symbol will change to
the +symbol. To check the current position of VALUE, press STORE/CLEAR
•GISTER/PRESET Display REGISTER/PRESET Display
Knob Position Reading Knob Position Reading
Large Hall 0Rich Plate 8
Vocal Hall 1Drum Plate 9
Piano Hall 2Vocal Plate A
Music Club 3Ranger b
Guitar Stage 4Chorus C
Small Room 5Canyon d
Inverse 6Multi Taps E
Gate 7Resonator F
Press the REGISTER/PRESET button to exit the Encoder Test.
Functional Tests
3-3

Performance Verification Lexicon
Front Panel Buttons and Footswitches
1.Turn the REGISTER/PRESET knob to select 14 CANYON. The display
should read: 13.
2. Press the REGISTER/PRESET button to enter the Button Test.
3. Verify that the display reads: 0.
4. Individually press each button and footswitch, and verify that the display
indicates the correct value according to the following table when each
button is pressed. When no buttons are being tested, 0should be
displayed.
Front Panel Button Footswitch
STORE/CLEAR =1Left Footswitch =4
PARAMETER/LEARN =2
REGISTER/PRESET =3
Right Footswitch= 5
5.
To exit the test, simultaneously press PARAMETER/LEARN and
STORE/CLEAR. Verify that 13 is displayed when the buttons are re-
leased.
Dynamic RAM
1.Turn the REGISTER/PRESET knob clockwise to select 7INVERSE. The
display should read: 6.
2. Press the REGISTER/PRESET button to enter the test. Verify that r
appears on the display. After 13seconds, the +symbol should appear on
the display.
3. Pressthe REGISTER/PRESET button to exit the test. The display should
read: 6.
MIDI
1.Turn the REGISTER/PRESET knob clockwise until the display reads: 1 1
.
2. Press the REGISTER/PRESET button to enter the test. Verify that r
appears on the display. After 4seconds, the + symbol should appear on
the display, followed by 11
.
3. Remove the MIDI cable and the Footswitch cable.
4. Power off Reflex.
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Reflex Service Manual
Setup
1. Connect stereo headphones to the Reflex rear panel Left Output
(Phones).
2. Using the 2audio cables forthe sine wave audio oscillator, connect the
left and right inputs of Reflex to the Yconnector and connect the Y
connector to the output of the sine wave audio oscillator.
3. Set the Reflex front panel OUTPUT control fully counterclockwise.
4. Set the Reflex front panel INPUT and MIX controls fully clockwise.
5. Power on Reflex, and power on the low distortion sine wave audio
oscillator.
6. Input a220Hz sine wave at -SOdBV to Reflex.
7. Turn the REGISTER/PRESET knob to select 1LARGE HALL. The
display should read: 1.
8. Put on the headphones.
9. Set OUTPUT to acomfortable listening level.
Smooth Pots
1. Individually sweep the INPUT, MIX and OUTPUTcontrols overtheir entire
range.
2. Verify that no pops, clicks or scratchiness are heard when turning the
controls.
Quick Listen
1.Set the INPUT and MIX controls fully clockwise.
2. Set OUTPUT to acomfortable listening level.
3. Vary the frequency on the oscillator.
4. Verify that no pops, clicks, buzz, or other audio artifacts are heard.
Shock Test
1.Lift each end of Reflex 4" off the bench and drop it.
2. Verify that no audio, display, or LED intermittents are caused by this
action.
NOTE: TO AVOID DAMAGE TO THE UNIT, KEEP ONE CORNER OF
THE UNIT TOUCHING THE BENCH AT ALL TIMES.
Headroom LED
1.Disconnect the headphones.
2. Set both the INPUT and OUTPUT controls fully counterclockwise.
3. Increase the oscillator level to -35dBV.
4. Slowly increase INPUT over its entire range.
5. Verify that the headroom LED, lights green, then red during the clockwise
rotation of the knob.
6. Remove audio cables and power cable from Reflex.
Factory Settings
1.Set all front panel knobs fully counterclockwise.
2. Set the REGISTER/PRESET and VALUE knobs to their 6:00 positions.
Performance Verification
Listening Tests
3-5

Performance Verification Lexicon
Diagnostics Reflex software contain two categories of Diagnostics: Power Up Diagnos-
tics, which are run automatically each time the unit is powered on, and User
Diagnostics, which are invoked by simultaneously pressing the front panel
STORE/CLEAR and PARAMETER/LEARN buttons during power up.
Power Up Diagnostics when power is first applied to the system, aseries of diagnostic tests are run
to help avoid having the normal operating software attempting to run on faulty
hardware.
When the system first powers up, the maskable interrupt (from the UART/
MIDI IN) is disabled, the UART is initialized and the nonmaskable interrupt
(NMI) is disabled by toggling DlSABLEINT/from Output Register 2(U5 pin 9)
low. Nonmaskable interrupts, which occurfrequently (every 51 2us), must be
tightly controlled. Alow on the DISABLEINT/ line prevents the NMI/ line from
being pulled low and triggering an interrupt. Oncethe DISABLEINT/ line is low
the software loads software into the Lexichip which allows it to output aWC/
signal at the properfrequency (32kHz). At this point, the software jumps to the
diagnostic section, which turns on all of the front panel LEDs except the
headroom LED for approximately two seconds. It turns off the LEDs, checks
to see if akey was pressed and then begins running its tests.
At power up the following diagnostic tests are run:
AROM Test
BRAM Test
CWCS Test
EInterrupt Test
Upon completion of these tests, the SRAM (U9) is cleared to all Os, and the
normal operating software is run.
Pass/Fail of Power Up Diagnostics
Whenthe Power Up Diagnostics pass, the display stays blank until the normal
operating software displays the letter L(while the registers are read from the
EEPROM), then the selected preset or register ID number. If atest fails, the
letter ID of the test is displayed and the test is continuously re-run. To skip a
failing test, press and hold the STORE/CLEAR and PARAMETER/LEARN
buttons for approximately 1/2 second.
ROM Test
This is achecksum test of the system ROM. Achecksum test is performed by
reading each memory location in ROM and adding the stored value stored.
This number is compared with the total calculated when the software was first
assembled. Amismatch indicates aproblem with the ROM or with the Z80’s
ability to read the ROM (shorted address line, etc...). The last two memory
locations are reserved to store the comparison value. In practice, the ROM
test is primarily useful for verifying that the contents of the ROM were
transferred correctly from the master and are uncorrupted.
3-6

Reflex Service Manual Performance Verification
RAM Test
Several tests that get performed on the SRAM (U9) in the system. First, the
RAM is filled with the value 55 hex (0101 0101 binary), then each memory
location is read to see if it contains 55. If 55 is in the memory location, the
location is filled with AA hex (1010 1010 binary), and the next location is
processed. Once the RAM has been checked for 55’s and filled with AA’s, the
process is repeated, checking for AA’s and storing O’s. Then, the memory is
checked for O’s and the test exits.
WCS Test
The WCStest is identical to the SRAM test except that it is run on the program
memory space in the Lexichip 2(U14).
Interrupt Test
This test verifies that the NMI Interrupt is working, and that it occurs at the
proper intervals. The interrupt is allowed to run for aperiod of time that should
allow 20 interrupts. Acount of the interrupts is kept and compared for
overshoot and undershoot. More than 21 interrupts means the interrupt is too
short. Fewer than 19 interrupts means it’s too long. Note that the User
Diagnostics allow you to distinguish overshoot and undershoot.
User Diagnostics
The User Diagnostics provide more interactive access to the tests run by the
Power Up Diagnostics, and also provide access to tests, troubleshooting
tools and system configuration tools not available from the normal operating
system.
NOTE: As User Diagnostics must operate within the limits of the front panel
controls, it is not always readily apparent to acasual observerwhat the current
mode of the system is. Care should be taken to keep track of where you are
and how you got there.
Accessing User Diagnostics
To access User Diagnostics, press and hold the STORE/CLEAR and PA-
RAMETER/LEARN buttons during power up. The letter dappears on the
display to indicate you have entered User Diagnostics. Release the buttons
and wait approximately one second. To begin using the diagnostics, press
STORE/CLEAR, PARAMETER/LEARN or REGISTER/PRESET.
The Diagnostics Menu
The User Diagnostics contain 21 tests and tools. Turn the REGISTER/
PRESET knob to select sixteen of these menu items, each of which has a
displayed ID number. Execute any displayed item by pressing STORE/
CLEAR. PARAMETER/LEARN orthe REGISTER/PRESET button. An addi-
tional five menu items are selected in an “Alternate Mode”. Access this mode
by continuously holding down PARAMETER/LEARN. In this mode, the
decimal point will light. While holding down PARAMETER/LEARN, turn the
REGISTER/PRESET knob to select an item and press the STORE/CLEAR
or REGISTER/PRESET button to execute any displayed item.
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