Audio Research Definition DSi200 User manual

3900 ANNAPOLIS LANE NORTH / PLYMOUTH, MINNESOTA 55447-5447 / PHONE: [phone] FAX: [phone]
www.audioresearch.com
Owner’s Manual
D E F I N I T I O N S E R I E S
Model DSi200
STEREO INTEGRATED AMPLIFIER

Contents
Model DSi200
Section Page No.
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Description of Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1, 2
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2, 3
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Operating Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Disposal and Recycling Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Model DSi200
INT EGRA TED AM P LI F I E R D S I 2 0 0 HI G H D E F I N I T I O N ®
POWER MONO INVERT MUTE
D I S P L A Y
MODEL DSI200
INTEGRATED AMPLIFIER
PLYMOUTH, MINNESOTA
MADE IN U. S.A.
MAX POWER CONSUMPTION
815 W50/60 HZ ˜
SERIAL
VOLTS
6A FUSE SLO-BLO
(T3.15A 230V)
CAUTION
FOR PROTECTION AGAINST
FIRE HAZARD, REPLACE
ONLY WITH SAME RATING FUSES.
BAL 1
TUNER AUX
BAL 2 CD
INVERT POWER
MUTEVOL DN VOL UP
BAL L BAL R
DSP DN DSP UP MONO
PROC
l
n
VOLUME INPUT
D E F I N I T I O N S E R I E S
+ -
RIGHT
OUTPUT
- +
LEFT
OUTPUT
WARNING!
RISK OF HAZARDOUS ENERGY!
MAKE PROPER SPEAKER
CONNECTIONS
SEE OWNERS MANUAL
WARNING!
RISK OF HAZARDOUS ENERGY!
MAKE PROPER SPEAKER
CONNECTIONS
SEE OWNERS MANUAL
BAL 1 BAL 2 BAL 2 BAL 1CD TUNER AUX /PROC AUX/PROC TUNER CD
RIGHT INPUTS LEFT INPUTS
D S i 2 0 0

Model DSi200
1
Preface
Please take time to carefully read and understand the fol-
lowing instructions before you install or attempt to operate
your Audio Research DSi200 integrated preamplifier.
Becoming familiar with the product and its correct operat-
ing procedures will help assure you of maximum musical
enjoyment and reliable operation. The effort you invest
now will be well rewarded in the years ahead.
Warnings
1. To prevent fire or shock hazard, do not expose this
product to rain or moisture.
2. This unit operates on voltages which can cause serious
injury or death. Do not operate with covers removed.
Any necessary servicing should be carried out by your
authorized Audio Research dealer or other qualified
electronics technician.
3. The 14-gauge power cord supplied with this unit is
safety-tested and is equipped with a proper grounding
plug. If used normally, it will provide a safe earth ground
connection of the chassis. Defeat of the grounding plug
or use of a power cord without a grounding plug, or any
unauthorized modification of the active circuitry or
controls of this unit, automatically voids warranty cover-
age, and could cause injury or death.
4. For safe operation and protection against fire hazard,
replace fuses only with those of the same type and
rating as those supplied with this unit.
Packaging
Save all packaging accompanying this product. You have
purchased a precision electronic instrument, and it should
be properly cartoned any time shipment becomes neces-
sary. It is very possible that this unit could be damaged
during shipment if repackaged in cartoning other than that
designed for it. The original packaging materials help pro-
tect your investment from unnecessary damage, delay and
added expense whenever shipment of this unit is required.
Accessories
Spare Fuses:
2– 6 Amp MDQ slo-blo (100 & 120v)
2–T 3.15A Super-Time-Lag TT (220 -240V)
Description of Controls
F ront Panel Rotary Contro l s :
The DSi200 has two microprocessor-driven rotary
controls.
Vo l u m e
The rotary control on the left adjusts Volume (output level)
up or down for both R and L channels. Volume control is
also selectable via Vol DN and Vol UP buttons on the
remote control. Volume adjustment is indicated in the
display window by numeric digits on 0–103 scale.
Do not turn volume up beyond normal listening levels
when “mute” is engaged to avoid unexpected or possibly
damaging sound levels. Reduce volume level whenever
changing input sources, even when muted.
Input
The rotary control on the right selects any of 5 input
sources connected to the DSi200: Bal 1, Bal 2, CD, Tuner
and Aux. Each of these sources may also be selected via
direct access buttons on the remote control. The
selected source is indicated in the display window.
F ront Panel and Remote Control Buttons
POWER ON/OFF: Supplies power from A.C. wall outlet to
DSi200; indicated by active display window. Function
also on remote control.
For approximately 5 seconds after start up, “Mute”
appears in the display window and flashes until the auto-
matic muting cycle is completed. This also occurs in the
event of power interruption. Upon completing the cycle,
“Mute” will cease flashing. The DSi200 will remain muted
until normal operation is selected by pressing the “Mute”
button.
MUTE: When activated, electrically mutes all output of the
DSi200; indicated by “Mute” in display window. This con-
trol should be activated before switching inputs, changing
connections or shutting down your audio system to help
protect your speakers from unexpected signal pulses.
When deactivated, “Mute” disappears from the display win-
dow allowing normal operation. Function also on remote
control.
The DSi200 also has automatic muting to help protect sys-
tem components during A.C. power interruptions or low
line voltage. When sensing these conditions, the unit
automatically goes into “Mute” and disables all outputs.
The 5-second warm-up timer will restart and “Mute” will
flash in the display window when normal power condi-
tions have been restored.
Note that automatic muting is only designed to protect
against power line interruptions or severe voltage drop. It
will not mute in the event of subsonic transmissions from
a faulty input source or speaker malfunction.

PROCESSOR (PROC): The Aux/Proc input may be used as a
normal input for a line-level source, or it may be used as a
fixed level pass-through for use with a home theater
processor. When the Processor button on the remote con-
trol is engaged, “PROCESSOR” will appear on the display,
the volume will not be adjustable, and the gain will be
fixed at 26dB (typical of a separate amplifier). Fixing the
gain will allow the home theater processor (connected to
Aux/Proc) to control the overall volume of the complete
multichannel system, including the DSi200.
WARNING: Before unmuting the “PROC” input, be sure
to turn the volume down on the home-theater processor.
Never connect a line-level source (DVD player, tuner,
CD, etc.) and then select “PROC” input on the remote or
the speaker system could be damaged when the DSi200
is unmuted.
INVERT: Inverts absolute phase of output signal. Remem-
bers setting for each input independently. “Invert” disabled
in Processor mode.
VOLUME UP/ D O W N : Increases/decreases overall volume
level of both channels equally for whichever input has been
selected. Caution: do not turn up volume beyond normal
listening levels when “Mute” is engaged to avoid unexpect-
ed or possibly damaging sound levels. It is a good idea to
reduce volume whenever changing program sources, even
when muted. Function available on remote control buttons
and front panel rotary control on left.
M O N O : Sums L and R input for mono output from any
source selected. Remembers setting for each input indepen-
dently. “Mono” disabled in Processor mode.
Remote Control-Only Functions
DISPLAY DOWN/DISPLAY UP [DSP DN/DSP UP]: Decreas-
es/increases display intensity, offering six levels of bright-
ness and display “off”. If display “off” is selected, a small
segment of pixels remains illuminated in the center of the
display window as a reminder the unit is turned on. In
display “off” mode the display will illuminate for 10
seconds when any button (except Power on/off) is selected,
allowing for control function navigation.
BALANCE (BAL L / B A LR ) : Adjusts balance left or right
Adjustment appears in display window as movable marker
on bar graph. Useful for compensating for uneven speaker
placement or imbalanced output from a phono cartridge
or other source. Remembers setting for each input indepen-
dently. “Balance” disabled in Processor mode.
Connections
The Rear Panel has:
2– Sets of BAL input connectors (BAL 1, BAL 2)
3– Sets of SE input connectors (CD, TUNER, AUX/PROC)
4– Output binding posts (+) and (-), L & R
1– Power line cord 15A IEC connector for removable
power cord (supplied)
1– Power line fuseholder
IMPORTANT: Use the best available speaker wires and in-
terconnects. As your system improves in resolution from
the addition of quality components, it becomes increasingly
important to avoid the limitations of inferior system inter-
connections.
It is important sonically that your entire system be con-
nected so that the audio signal arriving at the speakers has
correct absolute polarity or phase (i.e. is n o t i n v e r t e d ) .
Connect the black or (-) speaker terminal to the wire that
connects to the appropriate-channel (-) gold binding post
on the DSi200. Connect the red or (+) speaker terminal to
the wire that connects to the appropriate-channel (+) bind-
ing post on the DSi200. Tighten the binding posts firmly to
assure good contact for best sonic results.
For “b i - w i r ed” loudspeaker systems (i.e. running separate
wires to bass and treble speaker terminals), simply repeat
the above instructions, taking care that all connections
have the same (+) or (-) polarity.
Connect the DSi200 to source components, using only the
highest grade of audio interconnect cables. To avoid sonic
degradation use the shortest practical length of
cables.
A.C. POWER CONNECTIONS: It is important that the
DSi200 be connected via its supplied 15 amp IEC 14-gauge
power cord to a secure, dedicated A.C. power receptacle.
Never connect to convenience power receptacles on other
equipment. Best results are usually achieved by plugging
the DSi200 directly into wall outlets.
The AC power source for the DSi200 amplifier should be
capable of supplying 6 amperes for 100 or 120 volt units,
or 3 amperes for 220 or 240 volt units.
For the very best performance on domestic 100 or 120 volt
circuits, the DSi200 should be connected to its own AC
power circuit branch, protected by a 15 amp breaker. The
other audio equipment should be connected to a different
power circuit and breaker.
The DSi200 uses a grounding system that does not require
a ground-lifter adaptor plug on the A.C. power cord to min-
imize hum. The power cord supplied with the
DSi200 has a standard grounding plug to provide maxi-
mum safety when properly connected to a grounded wall
receptacle. If there is any question regarding proper ground-
ing procedures in your installation, seek help from a quali-
fied technician. Caution should be taken before using
custom after-market power cords: they must be at least
Model DSi200
2

14-gauge and have a standard grounding plug properly
installed. These power cords are to be used with caution,
at the sole risk of the owner.
Installation
The amplifier may be installed in a ventilated cabinet;
observe the following guidelines to maximize the perfor-
mance and service of your amplifier.
With proper installation, the DSi200 may be left on contin-
uously for maximum performance on demand; it will draw
38 watts of AC power at idle. However, the DSi200 has
been designed and engineered to minimize any “warm up”
necessary for best sonics; generally, a half-hour to 45 min-
utes of actual playing time will bring the amplifier around
to more than acceptable performance levels, with some
additional improvement noticeable over the next hour or
two. Warm-up characteristics will depend upon ambient
room temperature at start-up, the nature of the installation
and the resolving power of the associated equipment.
Operate the DSi200 only in a horizontal (upright) position.
Adequate airflow and proper cooling can be maintained
only if there is no restriction around the unit.
The five (5) non-marring feet provide adequate spacing and
mechanical damping only from a smooth, hard surface.
Never operate the unit while it is sitting on a soft, irregu -
lar surface such as a rug or carpet.
If the unit is to be operated in an enclosure such as an
equipment rack, make certain that adequate air flow above
and below the unit is provided. The “ambient” operating
temperature should never exceed 120º F or 49º C. Improper
installation will cause premature component failure and
will affect your warranty, as well as the service life of
the unit.
It is normal for the DSi200 power amplifier to run slightly
warmto the touch. All components within are operated at
safe, conservative levels and will not be improperly affect-
ed, providing the requirements outlined above are adhered
to.
Do not operate your DSi200 without the top and bottom
covers installed. These are required both for safety as well
as shielding from interference (except in service operations
by qualified personnel).
Operating Procedure
Start-up:
1.Make sure you have read and complied with the
INSTALLATION AND CONNECTION instructions prior
to attempting operation.
2. Secure all rear-panel connections between DSi200, and
input sources, and loudspeakers.
3.Make sure the DSi200 is properly connected to a ground-
ed high-current power receptacle via the supplied
14-gauge, 3-prong grounded power cord (see AC POWER
CONNECTIONS).
4. Turn on source component(s) to be used.
5. Press Power switch (either on remote or front panel).
The display will illuminate and the MuteLED will flash
for approximately 5 seconds while power supply stabi-
lizes, indicating operation of automatic muting circuit.
After this automatic muting period the word “MUTE”
will stay on, indicating that your DSi200 is in the “mute”
position. Adjust the Volume control to the minimum
level. Press “Mute” button to initiate operation. When
the “o p e r a t e” position is manually selected the word
“MUTE” will turn off, indicating the DSi200 is ready for
operation.
Note: If the display does not come on, check the line fuse
for possible failure. An extra fuse for A. C. power is
included with your DSi200.
6. Press Input selector for desired source; set remaining
switch options to desired positions.
7. Activate selected input source, then deactivate Mute
switch and adjust Volume control as necessary.
8.Your DSi200 should now operate satisfactorily. However,
a full stabilization or warm-up time of approximately one
half hour is recommended for best sonic performance.
Shut-Down:
1. Activate “Mute” function.
2. Set Volume level to “0”.
3. Press Power switch to “off ”.
4. Turn off input sources.
Troubleshooting:
It is possible for a static discharge to temporarily disable
the microprocessor that allows the controls to function. If
this should occur, depress the “Mute” button, then turn off
the DSi200 and unplug from the A.C. receptacle for 60
s e c o n d s . Reconnect the A.C. plug and turn the unit back
on. The controls should resume normal operation. If the
problem persists, contact your dealer or Audio Research
Customer Service at 763-577-9700.
Model DSi200
3

Servicing
Because of its careful design and exacting standards
of manufacture, your DSi200 should require no routine
maintenance. The remote control's batteries (AAA) should
be replaced once a year.
CAUTION: Your DSi200 contains sufficient levels of voltage
and current to be lethal. Do not tamper with a
component or part inside the unit. Refer any needed
service to your authorized Audio Research dealer or other
qualified technician.
Should service be necessary, please contact your
Audio Research dealer, or Audio Research Customer Service
at 763 577-9700.
Cleaning
To maintain the new appearance of this unit, occasionally
wipe the front panel and top cover with a soft, damp (not
wet) cloth to remove dust. A mild, non-alkaline soap solu-
tion may be used to remove fingerprints or similar
smudges. Cleaners containing abrasives should not be used
as they will damage the anodized finish of the front panel.
A small, soft paint brush is effective in removing dust from
bevels, the recessed nameplate and other features of the
front panel.
Disposal and Recycling Guidelines
To dispose of this electronic product, do not place in land-
fill. In accordance with the European Union Waste Electri-
cal and Electronic Equipment (WEEE) directive effective
August 2005, this product may contain regulated materials
which upon disposal require special reuse and recycling
processing.
Please contact your dealer or importing distributor for
instructions on proper disposal of this product in your
country. Or, contact Audio Research Corporation (763-577-
9700) for the name of your importing distributor and how
to contact them.
Packing and shipping materials may be disposed of in a
normal manner.
Limited Warranty
Audio Research Corporation products are covered by a 3-
Year Limited Warranty, or a 90-Day Limited Warranty
(vacuum tubes). This Limited Warranty initiates from the
date of purchase, and is limited to the original purchaser, or
in the case of demonstration equipment, limited to the
balance of warranty remaining after original shipment to
the retailer or importer.
In the United States, the specific terms, conditions and
remedies for fulfillment of this Limited Warranty are listed
on the warranty card accompanying the product in its
shipping carton, or may be obtained from the authorized
retailer or from the Audio Research Customer Service
Department. Outside the United States, the authorized
importing retailer or distributor has accepted the responsi-
bility for warranty of Audio Research products sold by
them. The specific terms and remedies for fulfillment of
the Limited Warranty may vary from country to country.
Warranty service should normally be obtained from the
importing retailer or distributor from whom the product
was purchased.
In the unlikely event that technical service beyond the abil-
ity of the importer is required, Audio Research will fulfill
the terms and conditions of the Limited Warranty. Such
product must be returned at the purchaser's expense to the
Audio Research factory, along with a photocopy of the
dated purchase receipt for the product, a written descrip-
tion of the problem(s) encountered, and any information
necessary for return shipment. The cost of return shipment
is the responsibility of the purchaser.
Model DSi200
4

Specifications
POWER OUTPUT: 200 watts per channel into 8 ohms,
1% THD; 300 watts per channel into 4 ohms, both channels
driven.
FREQUENCY RESPONSE: (-3dB points at 1 watt) 5Hz to
55 kHz.
INPUT SENSITIVITY: 0.93V RMS for rated output (32.7dB
Gain) single-ended or balanced.
INPUT IMPEDANCE: 60K ohms single-ended, 120K ohms
balanced differential.
INPUTS: (5): BAL1, BAL 2, CD(SE), Tuner (SE), Aux (SE).
MAXIMUM INPUT: 20V RMS BALANCED, 10V RMS SE.
OUPUT POLARITY: Non-inverting from single-ended inputs.
Balanced pin 2+ (IEC-268).
OUTPUT REGULATION: 0.06dB 8 ohm load to open circuit
(Damping factor 167).
OUTPUT CURRENT: 15 amps peak at protective shutdown.
SLEW RATE: 5 volts/microsecond. (20% maximum duty
cycle).
RISE TIME: 5.0 microseconds.
HUM & NOISE: 800 microvolts RMS (94dB below rated
output IHF A-weighted).
CONTROLS: Volume (104 steps), Select Input.
Push Buttons: Power, Invert, Mono, Mute.
POWER SUPPLY CAPACITANCE: 160,000 uF total.
POWER REQUIREMENTS: 100-125VAC 60Hz (200-250VAC
50Hz) 445 watts at rated output (200WPC 8 ohms), 735 watts
at 300WPC 4 ohms, 38 watts idle, Standby 1 watt.
DIMENSIONS: 19" (48 cm) W (standard rack panel) x 51/4"
(13.3 cm) H x 141/4" (36.2 cm) D (front panel back). Optional
handles extend 11/2" (3.8 cm) forward of the 1/4" thick front
panel. Output connectors extend 0.9" behind rear panel.
WEIGHT: 37.2 lbs. (16.9 kg) Net; 43.3 lbs. (19.7 kg) Shipping.
Specifications subject to change without notice.
©2009 Audio Research Corporation.
5
Model DSi200

Model DSI200
5

Model

Specifications
FREQUENCY RESPONSE: +0-3dB, 0.2Hz to 160kHz at
rated output (Balanced, 200k ohms load)
DISTORTION: Less than .01% at 2V RMS BAL output.
GAIN: Main output: Selectable for each input: 24dB, 18dB,
12dB Balanced output. (18dB, 12dB, 6dB SE output.)
Record output: 0dB (Processor input: 0dB balanced).
INPUT IMPEDANCE: 120K ohms Balanced, 60K ohms SE.
Inputs (8): Tuner, Phono, CD, Video, Aux 1, Aux 2, Monitor,
Processor ( XLR and RCA connectors).
OUTPUT IMPEDANCE: 700 ohms Balanced, 350 ohms SE
Main (2), 20K ohms minimum load and 2000pF maximum
capacitance. Outputs (3): 2 Main, 1 Record (XLR and RCA
connectors).
OUTPUT POLARITY: Non-inverting.
MAXIMUM INPUT: Low Gain: 48V RMS BAL, 24V RMS SE,
Medium Gain: 24V RMS BAL, 12V RMS SE, High Gain: 12V
RMS BAL, 6V RMS SE.
RATED OUTPUTS: 2V RMS 1Hz to 100kHz into 200K ohm
balanced load (maximum balanced output capability is 15V
RMS at less than 0.5% THD at 1kHz).
CONTROLS: Rotary volume selector (104 steps) and
rotary input selector.
Push buttons: Power, Mono, BAL/SE, Proc, Monitor, Mute.
Also remote buttons: Display, Bal L, Bal R, Hours, Invert, Gain.
POWER SUPPLIES: Electronically-regulated low and high
voltage supplies. Automatic 50 sec. warm-up/brown-out mute.
Line regulation better than .01%.
NOISE: 1.3uV RMS residual IHF weighted balanced equivalent
input noise with volume at 1 (100dB below 2V RMS output).
TUBE COMPLEMENT: 2-6H30P dual triode, ( Hybrid
JFET/ tube audio circuit, solid-state power supply.)
POWER REQUIREMENTS: 105-130VAC 60Hz (210-260VAC
50/60Hz) 50 watts maximum.
DIMENSIONS: 19" (48 cm) W x 5.25" (13.4 cm) H (standard
rack panel) x 12" (30.5 cm) D. Handles extend 1.50"
(3.8 cm) forward of the front panel.
WEIGHT: 16.5 lbs. (7.5 kg) Net; 26 lbs. (11.8 kg) Shipping.
Specifications subject to change without notice.
©2006 Audio Research Corporation.
800 watts maximum
SENSITIVITY: 0.9V RMS for rated output (32.7dB Gain) sin-
gle-ended or balanced.
POWER BANDWIDTH: (-3dB Points) 5Hz to 30 kHz into
8 ohms, or 4 ohms.

Installation of Vacuum Tubes
N o t e : This unit has been shipped with the vacuum tubes
installed in a protective foam block under the top cover.
Using a phillips-head screwdriver to loosen the fastening
screws, remove the top cover and set aside. Remove the
tubes carefully from the protective foam block and store
the foam block with the carton.
Warning!
Do not attempt to install or replace vacuum tubes
unless this unit is first turned off and disconnected
from A.C. power outlet. Unit should be connected to
A.C. outlet and turned on only after all vacuum tubes
have been instal led and appropriate panels
replaced and fastened. See owner's manual for
installation details.
Before replacing vacuum tubes, turn off unit, discon-
nect from A.C. outlet and allow existing tubes to cool
before attempting to remove and replace with new
tubes. Hot tubes may cause burns or other injury if
not first allowed to cool.
When replacing tubes, do not touch other compo-
nents, as the circuit may retain sufficient levels of
voltage and current to cause injury or death.
Co ntact Audio Research Customer Servi ce
(763-577-9700) if you have any questions about
installing or replacing vacuum tubes in this unit.
B A L / S E: Select as appropriate for each input. For source
components having balanced (XLR) connections to the
DSI200, select BAL. For single-ended (RCA) sources,
select SE. Once selected for an input source, the setting is
memorized.
MONITOR (MON): Selecting MONITOR (“MONITOR”
appears on display) routes Monitor input signal to the Main
outputs.
The Input Selector indicates what is routed to the Record
out. To exit the monitor position and return to program
source controlled by input selector (CD, Tuner, Phono, etc.),
press monitor switch again.
Note: The gain of the DSI200 through the monitor input is
not adjustable by gain selector button (on the remote), and
is fixed at “High” gain (the gain setting on the display is
unlit in the “Monitor” position).
D I S P L A Y : Selects one of nine display illumination levels,
including off. When off, the display can be reactivated for

10 seconds at a low level by pressing any button
(except Power) on remote or control on front panel.
B A L L/ B AL R: Adjusts balance left or right. Adjustment
appears in display window as movable marker on bar
graph. Useful for compensating for uneven speaker place-
ment or imbalanced output from a phono cartridge.
Tape Recording Procedure
When using the DSI200 as a control center for recording,
the program source to be recorded must be connected to
one of the six inputs controlled by the Input selector
switch or to the Processor input. This routes the selected
program to the Record output.
Note: If the Processor input is activated by selecting the
“Processor” switch position, all other inputs will be deacti-
vated. When recording from the Processor input to the
Record out of the DSI200, the level of the recording will be
dependent on the level setting of the processor.
If you own a three-head tape deck, and wish to monitor the
actual tape while making a recording (for a true “A-B” com-
parison of signals before and after recording), connect the
tape deck output to the Monitor input.
It is also possible to dub from one tape deck to another.
Simply connect the output from one tape deck to an un-
used set of inputs controlled by the Input selector (Tuner,
Phono, CD, etc.) on the DSI200. This signal will then
be routed to the second tape deck through the Record
output when the appropriate input is selected on the Input
selector.
H O U R S : When pressed, displays number of operating
hours vacuum tubes have been in service. WARNING: after
replacing tubes, this function should be reset to “0” only by
a qualified technician. Hours display can be reset to “0” by
pressing black button labeled “Reset Hours” located on
lower right corner of circuit board directly behind display
window. The preamp must be “On” to reset function–the
service technician must be careful to avoid any contact with
other circuit components during reset operation. Contact
Audio Research customer service (763-577-9700) for infor-
mation regarding this procedure.
GAIN: The Gain selector limits the input level to the
DSI200, with resulting Low, Medium and High labeled gain
option settings to the outputs. Note that the gain to the
single ended outputs at each of the three settings is half of
the gain to the balanced outputs at the same setting. The
gain options allow limiting the output of “h ot” high-gain
signal sources to the preamplifier's input circuitry and pre-
vents potential overloading. Properly used, this results in
extremely wide signal input range capability while preserv-
ing optimum use of the Volume control. For each input
source, simply set the Gain selector at the highest of the
three gain settings viewed on the display that allows you to
use the Volume control over the desired range without au-
d i b l e
distortion on peak levels from your program source. Once
you have selected the optimum gain setting for a given
input, the DSI200 will “memorize” it and return to that gain
setting each time you select that input. Note that the Gain
selector defaults to the “High” setting for each input unless
another is selected.
I N V E R T : Inverts absolute phase of the output signal.
Remembers setting for each input.
INPUT CONNECTORS: The DSI200 provides eight pairs of
BA L/SE input connectors: CD , Tu n er , P ho n o, V i de o , Aux 1,
A u x 2, Monitor and Processor. The BAL/SE selector
button (front panel and on remote) should be selected
to match the type of connection used (BAL or SE) on each
input.
Connect either the BAL or SE connectors for each input.
Never connect the BAL and SE connectors simultaneously
for any input.
OUTPUT CONNECTORS: Two pairs of BAL/SE main
outputs are provided.
RECORD OUTPUT: The BAL/SE tape outputs should be
connected to your recorder's “Record” or “Line” inputs.
These outputs provide a fixed-level two-channel signal
( R , L ) to your recorder from whichever input is selected.
The non-variable output level will be the same as the out-
put of the selected source.
It is possible to dub or copy from one recorder to another
by connecting the output of the source recorder to an
unused set of stereo inputs (Aux 1, Aux 2). The signal
will then be routed to the Record Out connectors when
that input source is selected.
12V IN/OUT REMOTE START JACKS: The +12V DC in-
put/output jacks provide the ability to remotely turn on and
off the preamp and other linked components such as power
amplifiers having similar capabilities.
Installation Instructions
While the DSI200 does not dissipate an unusual amount of
heat, it is important that it be provided with
reasonable airflow to assure long, trouble-free operation.
In addition, the following installation guidelines will help
insure maximum sonic performance as well as reliable
service:
1. Operate unit in upright and horizontal position, prefer-
ably on solid, non-metal shelving.
2. Do not stack the preamp on top of a power amplifier: not

only could this cause overheating, but hum may be
introduced into the preamp from the proximity of the am-
plifier's power transformer. Do not stack components or
other objects directly on top of the DSI200.
3. Do not place or operate your preamp on a soft or
irregular surface such as a rug. This will prevent proper
ventilation.
Operating Procedure
Start-Up:
1. Secure all rear-panel connections between DSI200, pow-
er amplifier(s) and input sources.
2. Plug three-prong power cord from rear of chassis into
grounded AC wall outlet. The Power switch defaults to
“off” when the unit is plugged into a power receptacle.
3. Press power switch (either remote or front panel). “Mute”
will will flash in the display window for approximately
50 seconds, then cease flashing and remain in the
display. Press “Mute” to initiate operation.
4. Select input source, then BAL or SE as necessary.
The DSi200 should be turned on a f t e r the source compo-
nents of your system. If the DSi200 is turned on before
other components, it will amplify any extraneous turn-on
noises those components might generate, which could
potentially damage the loudspeakers. Good operating
practice dictates that the amplifier should be turned on
last, and turned off first in an audio system.
PROCESSOR (PROC): May be selected by button on remote
control. Selects external A-V (home theater) processor as
input source and controller of volume level for R and L
channels provides Unity Gain when this input is selected.
When engaged, “PROCESSOR” will appear in the display,
and the volume control is not adjustable because gain is
fixed. The DSi200 will also mute the input after “PROC”
is engaged.
If electronic crossovers or other AC powered equipment is
used with the DSi200 it may be necessary to use “ground
lifter” adapters on the power plugs of that equipment to
minimize system hum. Generally, the lowest hum is
achieved when the only direct connection between audio
common “ground” and true earth ground occurs in the
preamplifier, through its grounded power cord. Other
equipment in the system should have some form of isola-
tion to prevent ground loops and associated hum.
The vacuum tubes inside your DSi200 are quality 6H30
dual triode tubes and with normal use should not need to
be changed for approximately 4,000 hours of use. Replace-
ment tubes should be of equivalent quality and are
available from Audio Research. Note that tube numbers
(V1 and V2) match printed numbers next to tube sockets
on circuit board.