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Page 31

Studio Reference

 

IIIII

 

&

 

II

II

II

II

II

  Professional Studio Amplifiers

Fig. 6.3  Studio Reference 

I

 Maximum Power Matrix

Maximum Power Specifications

Crown’s maximum power specifications represent the largest amount of output power you can expect from your ampli-
fier when it is driven to full output under the given conditions. These specifications can be used to prevent loudspeaker
and hearing damage.

The maximum power matrices include specifications for single cycle and 40 millisecond burst sine waves. Burst signals
act like large transient peaks that are present in common source signals. Loudspeakers can respond to a single cycle
burst, so the single cycle burst specifications should be used to help you protect your loudspeakers. In contrast, a
40 millisecond burst represents the typical response time of the human ear. Your ear will not respond to the entire
dynamic change of a burst that lasts less than 40 milliseconds.

The burst power specifications are provided at 0.05% THD which is a practical low distortion condition. Operating the
amplifier at levels higher than 0.05% THD can result in output power levels that are higher than those listed in the
maximum power matrices.

Maximum Power Notes:

All maximum power specifica-
tions are based on 0.5% regu-
lated AC mains with THD of
less than 1.0% and an ambi-
ent room temperature of 70° F
(21° C). Although it is an un-
usual condition, your amplifier
can function well with AC
mains voltages up to 10% over
the specified line voltage. With
overvoltage conditions, your
amplifier may be capable of
delivering instantaneous
power levels up to 20%
greater than the specifications
in the matrix.

1. A single cycle sine wave is

presented to the amplifier
and monitored for nonlinear
distortion. The average
power during the burst is
reported. Loudspeakers
must be able to withstand
this level if they are to be
safely used with this ampli-
fier.

2. A 40 millisecond sine wave

burst (10 percent duty cycle)
is presented to the amplifier
and monitored for nonlinear
distortion. Average power
during the burst is reported.
This power level is a mea-
surement of the amplifier’s
maximum transient power
that can be perceived by the
human ear.

8

Studio Reference 

I

 – 

Maximum Power (Watts)

Stereo/Mono

Mode

Bridge-Mono

(balanced output)

Parallel-Mono

16

4

Single Cycle Tone Burst

Load (Ohms)

AC Mains

120 VAC, 6 0 Hz

0.05% Dist Noise

(See note 1)

50 Hz

1,435

900

2,855

1,780

2,820

1,795

4

2

8

8

16

4

1,380

900

2,780

1,740

2,780

1,780

1 kHz

2,180

1,165

4,355

2,345

4,380

2,340

2,150

1,155

4,285

2,320

4,325

2,320

7 kHz

2,030

1,120

4,080

2,215

4,075

2,230

2,015

1,100

4,020

2,195

3,985

2,190

4

2

8

100 VAC, 50 Hz

Bridge-Mono

(balanced output)

Parallel-Mono

40 Millisecond Tone Burst

50 Hz

0.05% Dist Noise

(See note 2)

1,295

835

2,635

1,695

2,605

1,700

1 kHz

1,220

820

2,425

1,635

2,420

1,620

1,260

820

2,595

1,600

2,455

1,620

1,135

780

2,260

1,555

2,250

1,545

7 kHz

1,220

830

2,400

1,650

2,395

1,650

1,135

790

2,235

1,570

2,250

1,575

Stereo

(both channels

driven)

Stereo

(both channels

driven)

8

16

4

1,470

930

2,945

1,830

2,970

1,810

2,220

1,190

4,360

2,360

4,415

2,355

2,065

1,135

4,090

2,250

4,100

2,240

4

2

8

240 VAC, 50 Hz

Bridge-Mono

(balanced output)

Parallel-Mono

1,370

880

2,695

1,750

2,715

1,745

1,290

850

2,560

1,685

2,525

1,685

1,275

860

2,505

1,705

2,550

1,700

Stereo

(both channels

driven)

Summary of Contents for Studio Reference II

Page 1: ...294 8000 Studio Reference PROFESSIONAL STUDIO AMPLIFIERS OWNER S MANUAL Exported to select countries as Amcron Trademark Notice Studio Reference Smart Amp MPX 6 SMX 6 AMB 5 and grounded bridge are trademarks and Crown IOC ODEP IQ System and P I P are registered trademarks of Crown International Inc Other trademarks are the property of their respective owners K80604 0 8 95 ...

Page 2: ... Road Elkhart Indiana 46517 4095 U S A warrants to you the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown product for a period of three 3 years from the date of purchase by the original purchaser the warrantyperiod thatthenewCrownproductisfreeofdefects in materials and workmanship and we further warrant the new Crown product regardlessofthereasonforfailure exceptasexcludedinthisCrow...

Page 3: ...ions Magnetic Field CAUTION Donotlocatesensitivehigh gainequip ment such as preamplifiers or tape decks directly above or below the unit Because this amplifier has a high power density it has a strong magnetic field which can induce hum into unshielded devices that are located nearby The field is strongest just above and below the unit If an equipment rack is used we recommend locating the amplifi...

Page 4: ...peration 19 4 1 Precautions 19 4 2 Indicators 19 4 3 Protection Systems 20 4 3 1 ODEP 21 4 3 2 Standby Mode 21 4 3 3 Transformer Thermal Protection 21 4 3 4 Circuit Breaker 22 4 4 Controls 22 4 5 Filter Cleaning 23 5 Technical Information 24 5 1 Overview 24 5 2 Circuit Theory 24 5 2 1 Stereo Operation 24 5 2 2 Bridge Mono Operation 26 5 2 3 Parallel Mono Operation 26 6 Specifications 27 7 AC Power...

Page 5: ...former Network 17 3 16 Loudspeaker Fuse Nomograph 18 4 1 Indicators 19 4 2 Studio Reference Indicator States 20 4 3 Removing a Handle 22 4 4 Meter Switches 23 4 5 Input Sensitivity and Ground Lift Switches 23 5 1 Circuit Block Diagram 25 6 1 Studio Reference I Minimum Power Matrix 29 6 2 Studio Reference II Minimum Power Matrix 30 6 3 Studio Reference I Maximum Power Matrix 31 6 4 Studio Reference...

Page 6: ...tion com pany immediately Only you the consignee may ini tiate a claim for shipping damage Crown will be happy to cooperate fully as needed Save the ship ping carton as evidence of damage for the shipper s inspection Even if the unit arrived in perfect condition as most do save all packing materials so you will have them if you ever need to transport the unit NEVER SHIP THE UNIT WITHOUT THE FACTOR...

Page 7: ...itry delivers incredible voltage swings without using stressful output transistor configurations like other more traditional amplifiers This results in significantly lower distortion and superior reliability Patented ODEP Output Device Emulation Protection circuitry detects and compensates for overheating and overload to keep the amplifier working when others would fail IOC Input Output Comparator...

Page 8: ... Section 4 2 D Signal Presence Indicators These indicators flash synchronously with the amplifier s audio output to show signal presence Note These indi cators may not flash at very low input signal levels See Section 4 2 E Enable Indicator This indicator lights when the amplifier has been en abled or turned on and AC power is available F Enable Switch This push button is used to turn the amplifie...

Page 9: ...d easily They accept banana plugs spade lugs or bare wire N Stereo Mono Switch This switch is used to select one of three operating modes Stereo mode is used for normal two channel operation Bridge Mono mode is used to drive a single channel with a load impedance of at least 4 ohms and Parallel Mono mode is used to drive a single channel with a load impedance of less than 4 ohms WARNING Turn off t...

Page 10: ...from overheating If you experience a cooling problem you should consider several factors that may be contributing to the problem including load impedance air flow and ambient air temperature Low impedance loads generate more heat than higher impedance loads To avoid impedance related cooling problems connect loads to each channel with a total impedance of at least 2 ohms in Stereo 4 ohms in Bridge...

Page 11: ...e air flowing through the rack If you plan to use air condi tioning refer to Section 7 for information on calculating the hourly thermal dissipation of your system 3 3 Wiring Figures 3 5 through 3 7 show common ways to set up a Studio Reference amplifier Input and output connec tors are located on the back panel Be careful when BLOWER OPTION 2 BLOWER OPTION 1 AIR FLOW FRONT OF RACK DOOR AIR FLOW E...

Page 12: ...to the center position and properly connect the output wiring as shown in Figure 3 5 Each output channel has two sets of binding posts to make it easier for you to con nect multiple loudspeaker cables to each channel Be sure to observe correct loudspeaker polarity see Fig ure 3 5 and be careful not to short the outputs CAUTION In Stereo mode never tie an amplifier s outputs together directly and n...

Page 13: ... 1 PUSH PUSH FX STUDIO REFERENCE AMPLIFIER MIXER LOUDSPEAKER CHANNEL 1 THE CHANNEL 2 INPUTS ARE NOT USED ADD A 14 GAUGE OR LARGER JUMPER BETWEEN THE CHANNEL 1 AND 2 RED BINDING POSTS CAUTION TURN OFF AMPLIFIER BEFORE CHANGING THIS SWITCH STEREO BRIDGE MONO PARALLEL MONO PARALLEL MONO MODE Fig 3 7 Parallel Mono Wiring is very different from the other modes and requires special attention To select P...

Page 14: ...oating or ground referenced sources They have a standard tip ring sleeve TRS configuration the tip is positive the ring is negative and the sleeve is ground see Figure 3 10 Wiring for various sources follows the XLR wiring examples in Figures 3 8 and 3 9 If you install a P I P module other than the P I P FX P I P BB P I P FMX or P I P FPX do not connect in put signals to the phone jacks The phone ...

Page 15: ...unded system and usually cause hum in the output A common source of ground loop problems is the placement of input cables parallel to power cables or near power transformers The magnetic field that surrounds these conductors can induce the 50 or 60 Hz alternating current into your input cables To prevent this type of ground loop it is always a good idea to locate input cables away from 1 Hz 10 Hz ...

Page 16: ...oduced by inadequate output wiring will reduce the amplifier s power to and motion control of the loudspeakers The latter problem occurs because Use Good Connectors 1 Male connectors on loudspeaker cables should not be exposed to prevent possible short circuits 2 Connectors which might accidentally cause the two channels to be tied together when making and breaking connections should not be used A...

Page 17: ...mping factor and mark it on the Damping Factor line Your amplifier can provide an phenomenal damping factor of 20 000 from 10 to 200 Hz in Stereo mode with an 8 ohm load In contrast most other amplifiers have a damping factor rating of 200 or less Higher damping factors yield lower distortion and greater motion control over the loudspeakers To give you a basis for comparison effective damping fact...

Page 18: ... module is most commonly used for long term loudspeaker thermal protection Each Smart Amp channel provides an independent smooth output limiter that controls average output levels over time while it allows transients to pass Most of the other P I P modules that provide signal driven compression can be used to prevent loud speaker damage from transient voltage These modules include the P I P AMCb P...

Page 19: ...le indicator is provided to show the amplifier has been turned on or enabled and that its low voltage Fig 4 1 Indicators power supply and on demand forced air cooling sys tem are working It does not indicate the status of the high voltage power supplies For example the enable indicator will stay on in the improbable event that one or both channels overheat causing an internal shut down of the high...

Page 20: ...rgy and the signal presence indicator will flash to show that there is audio output The channel s output is exceeding 0 05 distortion The input signal level is too high and IOC is reporting either an input overload or output clipping The amplifier is in standby mode Possible reasons 1 The amplifier has just been turned on and is still in the four second turn on delay 2 A P I P module such as an IQ...

Page 21: ...s for multiple units so the system s start up current demands are better distributed over time The amplifier s overvoltage protection circuitry will put both channels into standby when excessive AC mains voltage is detected Studio Reference amplifiers should not be operated with an AC mains voltage of more than 10 over the unit s rated voltage If dangerous subsonic frequencies or direct current DC...

Page 22: ...ur second turn on delay that immediately follows the indica tors will flash as described in Figure 4 2 After the delay the ODEP indicators should come on with full brilliance and the IOC and signal presence indica tors should function normally 4 After the turn on delay turn up your source to the maximum desired level 5 Turn up the amplifier s level controls until the maxi mum desired sound level i...

Page 23: ...e The noninverted and inverted signal lines for the P I P module are connected in parallel with the corre sponding lines of the phone jack inputs The input sig nal grounds are not paralleled Specifically XLR pins 2 and 3 are connected in parallel with the tip and ring of the corresponding phone jack However pin 1 of the XLR is not connected in parallel with the sleeve of the phone jack This makes ...

Page 24: ... load by increasing conductance simultaneously in the high side NPN and low side PNP stage while synchronously decreasing conductance of the high side PNP and low side NPN The two channels may be used together to double the voltage Bridge Mono or the current Parallel Mono presented to the load This feature gives you the flex ibility to maximize power available to the load A wide bandwidth multiloo...

Page 25: ...E PNP LOW OUTPUT STAGE PNP HI OUTPUT STAGE OUTPUT Vcc Vcc TRANSLATOR LVA LVA Vcc Vcc BIAS CURRENT LIMIT TRANSLATOR BALANCE INPUT STAGE P I P BALANCED INPUTS 1 4 PHONE XLR VARIABLE GAIN STAGE ERROR AMP DISPLAY BIAS BRIDGE BALANCE Vcc Vcc POWER SUPPLY CONTROL DC LF TIMER POWER Vcc Vcc ODEP A B A ODEP B ODEP SUPPLY D E DISPLAY D C DISPLAY E HS TEMP C ODEP 24 24 ENABLE OVER VOLTAGE ...

Page 26: ...nsor S100 gives the ODEP circuit vital infor mation on the operating temperature of the heat sink on which the output devices are mounted Should the amplifier fail in such a way that would cause DC across the output leads the DC low frequency pro tection circuit senses this on the negative feedback loop and shuts down the power supply until the DC is removed 5 2 2 Bridge Mono Operation By setting ...

Page 27: ...e 26 dB gain setting 20 1 3 or 26 dB 0 25 dB Studio Reference I At 0 775 volt sensitivity 103 1 12 or 40 dB 1 dB at 1 4 volt sensitivity 57 1 12 or 35 dB 1 dB Studio Reference II At 0 775 volt sensitivity 69 1 12 or 37 dB 1 dB at 1 4 volt sensitivity 38 1 12 or 32 dB 1 dB Power Power Bandwidth At standard 1 kHz power Studio Reference I 1 dB from 5 Hz to 27 5 kHz and 3 dB from 3 Hz to 32 8 kHz Stud...

Page 28: ...or Two balanced phone jacks on the back panel and two balanced three pin XLR connectors on the factory installed P I P FX see Section 8 for infor mation on optional P I P modules Input Impedance Nominally 10 K ohms balanced Nominally 5 K ohms unbalanced Input Sensitivity Settings include 0 775 volts or 1 4 volts for standard 1 kHz power or a 26 dB voltage gain see Section 4 4 for more information ...

Page 29: ...teed to meet or exceed their specifications for three years Further because our published 8 Studio Reference I Minimum Guaranteed Power Watts Stereo Mono Mode Stereo both channels driven Bridge Mono balanced output Parallel Mono 16 4 FTC Continuous Average 0 1 THD Noise See note 4 1 kHz 20Hz 20kHz 750 1 490 785 1 575 1 565 Maximum Average Load Ohms AC Mains 120 VAC 60 Hz 1 kHz 0 1 THD N See note 1...

Page 30: ...1 THD N See note 2 565 360 1 145 720 1 135 715 20Hz 20kHz 495 340 1 020 690 4 2 8 8 16 4 440 320 900 655 520 345 1 045 690 1 030 675 535 355 1 080 700 1 065 690 460 330 970 665 0 05 THD N See note 3 1 kHz 560 355 1 130 715 1 125 715 525 340 1 070 695 1 055 685 4 2 8 100 VAC 50 Hz Bridge Mono balanced output Parallel Mono Stereo both channels driven 8 16 4 465 355 915 700 580 375 1 145 740 1 155 73...

Page 31: ...ing instantaneous power levels up to 20 greater than the specifications in the matrix 1 A single cycle sine wave is presented to the amplifier and monitored for nonlinear distortion The average power during the burst is reported Loudspeakers must be able to withstand this level if they are to be safely used with this ampli fier 2 A 40 millisecond sine wave burst 10 percent duty cycle is presented ...

Page 32: ...55 1 685 935 1 670 920 855 470 1 750 965 1 730 955 4 2 8 100 VAC 50 Hz Bridge Mono balanced output Parallel Mono 40 Millisecond Tone Burst 50 Hz 0 05 Distortion Noise See note 2 605 375 1 245 750 1 205 755 1 kHz 580 370 1 185 755 1 170 745 650 385 1 315 785 1 330 785 610 385 1 230 780 1 220 770 7 kHz 585 375 1 185 770 1 170 765 610 395 1 240 800 1 220 790 Stereo both channels driven Stereo both ch...

Page 33: ... K FREQUENCY Hz 2 1 0 1 2 3 4 dB 5 6 7 4 ohm 8 ohm 1 watt DAMPING 20 100 1 K 10 K 20 K 100 10 1 000 10 000 100 000 OHMS 0 001 0 0001 0 01 0 1 1 FREQUENCY Hz 8 ohm 20 100 1 K 10 K 20 K FREQUENCY Hz 8 ohm Fig 6 5 Typical Frequency Response Fig 6 6 Typical Damping Factor Fig 6 7 Typical Output Impedance ...

Page 34: ...I I II II II II II Professional Studio Amplifiers 0 60 dB 40 20 80 100 120 100 20 1 K 10 K 20 K FREQUENCY Hz 45 90 135 0 45 90 135 100 20 1 K 10 K 20 K FREQUENCY Hz Fig 6 8 Typical Phase Response Fig 6 9 Typical Common Mode Rejection ...

Page 35: ...ge 35 Studio Reference I I I I I II II II II II Professional Studio Amplifiers 0 60 dB 40 20 80 100 120 100 20 1 K 10 K 20 K FREQUENCY Hz Studio Reference II Studio Reference I Fig 6 10 Typical Crosstalk ...

Page 36: ...s to current draw in amperes Current Draw amperes AC Mains Power Draw watts x AC Mains Voltage Power Factor 83 The power factor constant of 0 83 is needed to compensate for the difference in phase between in the AC mains voltage and current The following equation was used to calculate thermal dissipation Total output power with all channels driven watts Thermal Dissipation btu hr Quiescent Power D...

Page 37: ...5 3 3 2 Duty Cycle AC Mains Power Draw Watts btu hr Current Draw Amps 3 5 2 9 2 3 1 7 1 1 5 3 4 4 3 4 2 4 1 5 4 Ohm Stereo 8 Ohm Bridge Mono 2 Ohm Parallel Mono Studio Reference II 245 215 180 145 115 kcal hr 1 360 1 150 940 730 520 100 120 V 220 240 V Thermal Dissipation btu hr Current Draw Amps kcal hr 100 120 V 220 240 V Thermal Dissipation AC Mains Power Draw Watts Fig 7 2 Studio Reference II ...

Page 38: ...o function as a stand alone unit as part of the IQ System s distributed intelligence Features include a smooth output limiter for transparent loudspeaker pro tection power supply gates for energy savings ODEP conservation which protects the output devices with precision input signal control interrupt driven report ing that lets you define error conditions and config urable short detection CLP Prog...

Page 39: ... three pin female XLR connectors and two female phono jacks for quasi balanced or unbalanced operation FXT I N P U T I N P U T 3 1 2 GND Programmable Input Processor P I P C H 2 C H 1 PUSH PUSH P I P FXT uses balanced 1 1 transformers to isolate the amplifier from the input signal It has balanced female three pin XLR connectors PA Programmable Input Processor P I P LINE MIC MIC LEVEL C H 2 I N P U...

Page 40: ...original factory pack A list of authorized service centers in your area can be obtained from our Technical Support Group 9 2 2 Factory Service To obtain factory service fill out the service information page that follows and send it along with your proof of purchase and the defective unit to the Crown factory For warranty service we will pay for ground shipping both ways in the United States after ...

Page 41: ...__________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ _________________________________________________________...

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