Crown SR-I, SR-II, Studio Reference I, Studio Reference II Specifications

Studio Reference I

T

STUDIO REFERENCE SERIES

Studio Reference II

he stunning realism you will experience
when listening to a Crown

T

ence™ amplifi er will redefi ne your expec­tations. The evolution of this studio standard
ushers in a new era of powerful, ultraquiet
amplifi ers capable of faithfully reproducing
the most demanding of signals. This kind of
sonic integrity does not happen accidentally.
It demands the leadership and technical excel­lence for which Crown has long been known.

With the best transfer function in the industry,
ultra-high dynamic range and extraordinary
damping factor, your Studio Reference amplifi er
comes closer to the ideal “straight wire with
gain” than any other amplifi er. As you listen,
it will become apparent—the amplifi er’s low­frequency transient response is the standard by
which all others must be judged.

Studio Reference amplifi ers integrate several
cutting edge technologies that make them the
most accurate reference amplifi ers available.
For example, in Stereo mode each channel
can actually be treated as a separate amplifi er
because of its separate high-voltage power sup­plies and ultra-low crosstalk.

Crown’s unconventional Grounded Bridge™ cir­cuitry delivers incredible voltage swings with­out using stressful output transistor confi gu­rations like other more traditional amplifi ers.
This results in signifi cantly lower distortion and
superior reliability.

For more details about the Studio Reference I
and Studio Reference II, contact the Crown
Technical Support Group at 800-342-6939 or
574-294-8200. Also, visit the Crown Audio
website at www.crownaudio.com.

Specifi cations

The following apply to units in dual mode with both channels
driven into 8 ohm loads and an input sensitivity of 26 dB gain
unless otherwise specifi ed.

Power

Output Power: See power charts below.

Studio Reference I

4 ohm Stereo (per channel)

8 ohm Stereo (per channel)

8 ohm Bridge-Mono

16 ohm Bridge-Mono

2 ohm Parallel-Mono

4 ohm Parallel-Mono

*1 kHz Power: refers to maximum average power in watts
at 1 kHz with 0.05% THD.

®

Studio Refer-

*1 kHz
Power

1,160W

780W
2,220W
1,580W
2,315W

1,565W

fi

Features

• Patented ODEP® (Output Device Emulation
Protection) circuitry detects and compen­sates for overheating and overload to keep
the amplifier working when others would
fail.

®

(Input/Output Comparator) circuitry

• IOC
immediately alerts you of any distortion that
exceeds 0.05% to provide dynamic proof of
distortion-free performance.

• PIP™ (Programmable Input Processor) con­nector accepts accessories that tailor your
amplifi er to suit specifi c applications.

• Extremely wide dynamic range.

Performance

Frequency Response: ±0.1 dB from 20 Hz to

20 kHz at 1watt.
Phase Response: +5 to –15 degrees from 20

Hz to 20 kHz at 1 watt.

Signal-to-Noise (A-weighted) below rated full
bandwidth power: Studio Reference I: 120 dB.

Studio Reference II: 117 dB.
Total Harmonic Distortion (THD): Less than

0.1% at full bandwidth power.
Intermodulation Distortion (IMD): (60 Hz and

7 kHz 4:1)

Studio Reference I: < 0.005% from full
bandwidth power to 78 watts, rising
linearly to 0.025% at 78 milliwatts.

Studio Reference II

4 ohm Stereo (per channel)

8 ohm Stereo (per channel)

8 ohm Bridge-Mono

16 ohm Bridge-Mono

2 ohm Parallel-Mono

4 ohm Parallel-Mono

*1 kHz Power: refers to maximum average power in watts
at 1 kHz with 0.05% THD.

*1 kHz
Power

555W
355W

1,100W

715W

1,115W

710W

• Ultra-high damping factor delivers superior
loudspeaker motion control for the cleanest,
tightest bottom end you’ve ever felt—or
heard.

• Super-low harmonic and intermodulation
distortion give your amplifi er the best transfer
function in the business.

• Two mono modes (Bridge-Mono and Parallel­Mono) for driving a wide range of load imped­ances.

• Custom-designed, tape-wound, low-noise
toroidal supplies with extremely high power
density.

Studio Reference II: < 0.005% from full

bandwidth power to 36 watts rising linearly
to 0.025% at 36 milliwatts.

Crosstalk (below rated full bandwidth power):

Studio Reference I: >100 dB from 20

Hz to 400 Hz and >70 dB at 20 kHz.
Studio Reference II: >100 dB from 20 Hz
to 400 Hz and >65 dB at 20 kHz.

Damping Factor: >20,000 from 10 Hz to 400
Hz.

Voltage Gain (at the maximum level setting):

Studio Reference I:

103:1 ± 6% or 40 dB ±0.5 dB at

0.775 volt sensitivity.
57:1 ± 6% or 35 dB ± 0.5 dB at

1.4 volt sensitivity.
20:1 ± 6% at 26 dB gain ± 0.5 dB.

Studio Reference II:

69:1 ± 6% or 37 dB ± 0.5 dB at

0.775 volt sensitivity.
38:1 ± 6% or 32 dB ± 0.5 dB at

1.4 volt sensitivity.
20:1 ± 6% at 26 dB gain ± 0.5 dB

Load Impedance: Safe with all types of loads.
4-8 ohms in Stereo mode, 8-16 ohms in
Bridge-mono mode, and 2-4 ohms in Parallel­Mono mode.

AC Line Voltage and Frequency Confi gurations
Available (± 10%): 50 or 60 Hz; 100, 120, 200,

220 or 240VAC. Power draw at idle is 90 watts
or less.

OFF RESET ON

CAUTION: To prevent electric

shock do not remove the top or
bottom covers. There are no user
serviceable parts inside. Please
refer all servicing to qualified
service personnel. Disconnect
the power cord before removing
the P.I.P. module to access the
input sensitivity switch inside
the amplifier.

ATTENTION: Débrancher avant

d'ouvrir.

WARNING: To reduce the risk

of fire or electric shock, do not
expose this equipment to rain or
moisture.

Registered with the
U.S. Patent Office.

4,330,809
4,611,180

Designed and constructed by

the Professional Audio Division

of Crown International, Inc.

1718 West Mishawaka Rd.

Elkhart, Indiana 46517 U.S.A.

OFF

STEREO

BRIDGE

PARALLEL

MONO

MONO

CAUTION: Turn off the amplifier

before changing this switch!

INPUT GROUND LIFT
LIFT

(AFFECTS PHONE INPUTS ONLY.)

CH-2 CH-1

PUSHPUSH

INPUT INPUT

(MONO)

UNBALANCED
INPUT WIRING

GND

GND

FX

Programmable
Input Processor (P.I.P.)

This amplifier is equipped with a selectable input sensitivity. Remove the P.I.P. module to access the sensitivity switch.

BALANCED

INPUT WIRING

GND

+

TIP

RING

–

SLEEVE

CH-2 CH-1

+

SLEEVE

3

12

TIP

CH-2 CH-1

Class 1 output wiring is required.

BRIDGE-MONO OUTPUT WIRING

1

Turn the amplifier off.

2

Set the Stereo/Mono
switch to Bridge-Mono.

3

Output across the
“+” terminals only.
Ch-1 is positive.

PARALLEL-MONO OUTPUT WIRING

1

Turn the amplifier off.

2

Set the Stereo/Mono

–

switch to Parallel-Mono.

3

Add jumper (14+ gage)

+

across “+” terminals.

4

Output across the
Ch-1 terminals only.

Model: Reference 1

50/60 Hz AC Volts: 120 Current: 17.8 Amps
Maximum Output: 1,160 watts per channel
into 4 ohms at 1 kHz with no more than 0.02%
THD (in Stereo mode).

Model: Reference 2

50/60 Hz AC Volts: 120 Current: 8.8 Amps

ELECTRONIC EQUIPMENT

Maximum Output: 560 watts per channel into

ELKHART, IN 46517
MADE IN U.S.A.

4 ohms at 1 kHz with no more than 0.02% THD

SERIAL NUMBER

(in Stereo mode).

®

INTERNATIONAL, INC.

000000

Studio Reference I

Studio Reference II

–

+

0000

Controls

Power: A two-position front panel pushbutton

on/off switch. Four-second turn-on delay.
Level: An independent 31-position detented

front-panel level control for each channel.
Reset Switch: This back panel switch can be

used to trip and reset the AC mains circuit
breaker.

Stereo/Mono Switch: Back-panel switch
selects between Stereo, Bridge-mono, and
Parallel-mono modes.

Ground Lift Switch: The input signal ground
may be isolated from the AC ground with this
back-panel switch to help prevent unwanted
ground loops. It affects only the phone jacks.
It has no effect on the PIP module’s XLR
connectors. Activating the switch inserts an
impedance between the sleeve of each phone
input jack and the circuit ground.

Input Sensitivity Switch: The three-position
input sensitivity switch inside the amplifi er
can be accessed by removing the PIP module.
Settings include 0.775 volts and 1.4 volts for
rated output, and 26 dB voltage gain.

Meter Switches: Two switches behind the
front panel can make the output meters dis­play either the dynamic range of the output
signal in dB (factory default), or the output
level in dB.

Indicators

Signal Presence: The green front panel indi-

cator for each channel fl ashes synchronously
with the channel’s output signal to indicate its
presence.

Enable Indicator: This indicator lights when the
amplifi er has been “enabled” or turned on, and
AC power is available.

ODEP Indicators: During normal operation of
the amplifi er, the ODEP (Output Device Emu­lation Protection) indicators glow brightly to
show the presence of reserve thermodynamic
energy. They dim proportionally as energy
reserves decrease. In the rare event that energy
reserves are depleted, the indicators turn off
and ODEP proportionally limits the output drive
so the amplifi er can safely continue operating
even under severe conditions. These indicators
also help to identify more unusual operating
conditions.

Input/Output Comparator: The red Input/Output
Comparator (IOC) indicator for each channel
fl ashes if any type of distortion reaches 0.05%.

Dynamic Range/Level Meters: A fi ve-segment
output meter is provided for each channel. The
meters are factory-set to show dynamic range
of the signals in dB, which is computed as the
ratio of peak to average output power. Also,
the meter can optionally be set to show output
levels.

Input/Output

Input Connectors: Balanced ¼-inch (6.35-mm)

phone jack for each channel. Balanced three­pin female XLR connector on the PIP-FX for
each channel.

Input Impedance: Nominally 10 k ohms, bal­anced. Nominally 5 k ohms, unbalanced.

Input Sensitivity: Confi gurable for 26 dB gain,

0.775 volt sensitivity, or 1.4 volt sensitivity.
Output Connector: Two pairs of versatile 5-way

binding posts are provided for the output of
each channel so multiple loudspeakers can be
connected easily. They accept banana plugs,
spade lugs or bare wire.

Output Impedance: <10 milliohms in series
with 2.5 microhenries.

DC Output Offset: ± 2 millivolts.

Output Signal

Dual: Unbalanced, two channel.
Bridge-Mono: Balanced, single channel. Chan-

nel 1 controls are active; channel 2 controls
should be turned down.

Parallel-Mono: Balanced, single channel.
Channel 1 controls are active; channel 2 con­trols should be turned down.

Protection

Studio Reference amplifi ers provide extensive
protection and diagnostics capabilities. Protec­tion systems include ODEP, standby mode, an
AC circuit breaker and transformer thermal pro­tection. These systems will prevent amplifi er
damage in virtually any situation. A four-second
turn-on delay prevents power-on thumps.

Construction

Durable black fi nish on aluminum chassis.
Dimensions: EIA Standard 19-inch (48.3-cm)

rack mount width (EIA RS-310B), 7 inches
(17.8 cm) high and 16 inches (40.6 cm) deep
behind mounting surface and 2.75-inch (7-cm)
protrusion in front of mounting surface

Net Weight:

Studio Reference I: 60.7 lb (27.6 kg)
Studio Reference II: 56.1 lb (25.5 kg).

Shipping Weight:

Studio Reference I: 74.2 lb (33.7 kg)
Studio Reference II: 69.6 lb (31.6 kg).

Cooling: Flow-through ventilation from front to

sides. On-demand proportional speed fan.

Crown’s Three-Year, No-Fault, Fully Transferable Warranty

Crown offers a Three-Year, No-Fault, Fully Transferable Warranty for every new Crown ampli­fi er—an unsurpassed industry standard. With this unprecedented No-Fault protection, your new
Crown amplifi er is warranted to meet or exceed original specifi cations for the fi rst three years of
ownership. During this time, if your amplifi er fails, or does not perform to original specifi cations,
it will be repaired or replaced at our expense. About the only things not covered by this warranty
are those losses normally covered by insurance and those caused by intentional abuse. And the
coverage is transferable, should you sell your amplifi er.

See your authorized Crown dealer for full warranty disclosure and details. For customers outside
of the USA, please contact your authorized Crown distributor for warranty information or call
574-294-8200.

Crown International
P.O. Box 1000
Elkhart, IN 46515-1000
TEL: [phone]
FAX: [phone]FAX
www.crownaudio.com

Specifi cations subject to change without prior notice. Latest
information available at www.crownaudio.com.

Grounded Bridge, PIP, and Studio Reference are trademarks,
and Crown, ODEP, and IOC are registered trademarks of
Crown International. Other trademarks are the property of
their respective owners. Printed in U.S.A.

© 2003 Crown Audio, Inc.

7/03 136734-1