Crown Audio STUDIO AMPLIFIER manuale d’uso

® THE PROFESSIONAL AUDIO DIVISION OF CROWN INTERNATIONAL, INC. Printed on recycled paper. ©1995 by CROWN INTERNATIONAL, INC. P.O. Box 1000, Elkhart, Indiana 46515-1000 Telephone: 219-294-8000 S tu dio R efer en ce ™ PROFESSIONAL STUDIO AMPLIFIERS O WNER’S MANU AL Exported to select countries as Amcron. ® ® Trademark Notice: Studio Reference[...]

WORLDWIDE SUMMARY OF WARRANTY The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown 1 product, for a period of three (3) years from the date of purchase by the original purchaser (the “warranty period”[...]

The information furnished in this manual does not include all of the details of design, production, or variations of the equipment. Nor does it cover every possible situation which may arise during installation, operation or maintenance. If your unit bears the name “Amcron,” please substitute it for the name “Crown” in this manual. If you n[...]

Page 4 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers CONTENTS 1 We lc om e .......................................................................... 7 1.1 Features ................................................................... 7 2 Facilities .....................................................................[...]

Page 5 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers ILLUSTRA TIONS 1.1 Studio Reference I Am pli fie r ........................................... 6 2.1 Front Facilities ................................................................. 8 2.2 Rear Facilities ..........................................................[...]

Page 6 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Unpacking Instructions Please unpack and inspect your new amplifier for any damage that may have occurred during transit. If damage is found, notify the transportation com- pany immediately. Only you, the consignee, may ini- tiate a claim for shipping damage. Crow[...]

Page 7 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 1 Welcome The stunning realism you will experience when listen- ing to a Crown Studio Reference ™ amplifier will redefine your expectations. The evolution of this studio standard ushers in a new era of powerful, ultraquiet amplifiers capable of faithfully reprod[...]

Page 8 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 2 Facilities A. Level Controls Each channel’s output level can be adjusted accurately using the 31-position detented level controls on the front panel (see Section 4.4). B. ODEP Indicators During normal operation of the amplifier, the ODEP (Output Device Emulati[...]

Page 9 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers I. Reset Switch This back panel switch can be used to trip and reset the AC mains circuit breaker (see Section 4.3.4). J. Power Cord For 120 VAC, 60 Hz North American units, the Studio Reference I includes a 10 AWG power cord and NEMA TT30P plug, and the Studio Re[...]

Page 10 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 3 Installation 3.1 Mounting Studio Reference amplifiers are designed for standard 19 inch (48.3 cm) rack mounting or stacking without a cabinet. In a rack, it is best to mount units directly on top of each other. This provides the most efficient air flow and supp[...]

Page 11 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Fig. 3.5 Stereo Wiring you may want to install supplemental cooling like a rack-mounted blower or an air conditioner. A “squirrel cage” blower can be installed at the bottom of the rack so it blows outside air into the space be- tween the door and the front o[...]

Page 12 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers making connections, selecting sources and controlling output levels. The load you save may be your own! Crown is not responsible for damaged loads that result from carelessness or deliberate overpowering. CAUTION: Always disconnect the AC power and turn the level[...]

Page 13 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers greatly degraded. Also, turn down the channel 2 level control (fully counterclockwise). Note: The channel 2 input and level control are not de- feated in Bridge-Mono mode. Any signal feeding chan- nel 2 will work against the channel 1 signal, and usually results [...]

Page 14 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 3.3.4 Input Connection The balanced inputs have a nominal impedance of 10 K ohms (5 K ohms unbalanced) and will accept the line-level output of most devices. Phone jacks are pro- vided on the back panel, while the factory-installed P.I.P.-FX provides female XLR i[...]

Page 15 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers SOLVING INPUT PROBLEMS Sometimes large subsonic (subaudible) frequencies are present in the input signal. These can damage loudspeakers by overloading or overheating them. To attenuate such frequencies, place a capacitor in series with the input signal line. The [...]

Page 16 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers power cables and power transformers. We also recom- mend using shielded or twisted pair wire. With loose wires, use tie-wraps to bundle together each pair of in- put wires. This helps reduce magnetically-induced current by minimizing the cross-sectional area be- [...]

Page 17 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers amplifiers share a common cable tray or jacket, use tie-wraps to bundle individual conductors so the wires for each loudspeaker are kept close together. (Do not bundle wires from different amplifiers.) This reduces the chance of conduc- tors acting like antennas [...]

Page 18 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers available from most electrical supply stores. 3.3.6 Additional Load Protection Studio Reference amplifiers can deliver very high power levels, so it’s a good idea to add protection for your loudspeakers if it is not built-in. Loudspeakers are subject to thermal[...]

Page 19 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 4 Operation 4.1 Precautions Although your amplifier is protected from internal and external faults, you should still take the following pre- cautions for optimum performance and safety: 1 . Improper wiring for the Stereo, Bridge-Mono or Parallel-Mono modes can re[...]

Page 20 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers As dynamic range meters they show each channel’s ratio of peak-to-average power in dB. The dynamic range may be low for sources like AM/FM radio or low- quality recordings. Other sources like live music or high-quality recordings may be much higher. As out- put[...]

Page 21 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers and transformer thermal protection. These systems will prevent amplifier damage in virtually any situation. 4.3.1 ODEP Crown invented ODEP to solve two long-standing problems in amplifier design: to prevent amplifier shut- down during demanding operation and to i[...]

Page 22 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers former than in the output devices. This can overheat the transformer and activate its protection system. Studio Reference amplifiers are designed to keep work- ing under conditions where other amplifiers would fail. But even when the limits of a Studio Reference [...]

Page 23 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Fig. 4.5 Input Sensitivity and Ground Lift Switches Fig. 4.4 Meter Switches ® METER ON/ OFF SWITCH ON OFF DYNAMIC RANGE OUTPUT LEVEL METER MODE SWITCH 0 . 7 7 5 V 1.4 V SENSITIVITY SWITCH INSIDE ACCESS HOLE 26 d B UNBALANCED INPUT WIRING BALANCED INPUT WIRING CH[...]

Page 24 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 5 T echnical Information 5.1 Overview Studio Reference amplifiers incorporate several new technological advancements including real-time com- puter simulation of output transistor stress, low-stress output stages, an advanced heat sink embodiment and the Programm[...]

Page 25 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Fig. 5.1 Circuit Block Diagram FAULT ONLY ONE CHANNEL SHOWN NPN HI OUTPUT STAGE NPN LO W OUTPUT STAGE PNP LO W OUTPUT STAGE PNP HI OUTPUT STAGE + OUTPUT +Vcc –Vcc TRANSLATOR LV A LV A +Vcc –Vcc BIAS CURRENT LIMIT TRANSLATOR BALANCE INPUT STAGE P.I.P. BALANCED[...]

Page 26 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers output signal and the input signal from the gain pot, and drives the voltage-translator stage. From the error amp, the voltage translator stage chan- nels the signal to the Last Voltage Amplifiers (LVAs) depending on the signal polarity. The +LVA (Q104 and Q105) [...]

Page 27 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 6 Specifications The following applies to units in Stereo mode with 8 ohm loads and an input sensitivity of 26 dB gain unless otherwise specified. Low-Distortion 1 kHz Power: r efers to maximum average power in watts at 1 kHz with 0.02% THD and noise. Standard 1 [...]

Page 28 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Sensitivity: A three-position switch inside the P.I.P. com- partment used to select the input sensitivity for both chan- nels: 0.775 or 1.4 volts for standard 1 kHz power, or a 26 dB voltage gain. Meter On/Off : A two-position switch behind the front panel used t[...]

Page 29 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Crown specifications are guaranteed for three years. In an effort to provide you with as much information as possible about the high power-producing capabilities of your amplifier, we have created the following power matrices. Minimum Guaranteed Power Specificati[...]

Page 30 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 8 Studio Reference II – 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 470 340 960 680 555 360 1,105 720 1,10[...]

Page 31 Studio Reference I I I I I & 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. The[...]

Page 32 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Fig. 6.4 Studio Reference II Maximum Power Matrix 8 Studio Reference II – 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% Distortion + Noise (See note 1) [...]

Page 33 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 10 100 1 K 10 K 100 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 Typ[...]

Page 34 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) +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 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 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 7 AC Power Draw and Thermal Dissipation This section provides detailed information about the amount of power and current drawn from the AC mains by Studio Reference amplifiers and the amount of heat produced under various conditions. The calculations presented he[...]

Page 37 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 8 Ohm Stereo / 16 Ohm Bridge-Mono / 4 Ohm Parallel-Mono L O A D 50% 40% 30% 20% 10% 645 535 425 315 205 970 840 705 575 440 975 795 620 445 270 345 290 240 185 135 7.8 6.4 5.1 3.8 2.4 11.7 9.6 7.5 5.3 3.2 Duty Cycle AC Mains Power Draw (Watts) btu/hr Current Draw[...]

Page 38 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 8 Accessories 8.1 P.I.P. Modules One advantage of Studio Reference amplifiers is the ability to customize them using P .I.P . (Programmable In- put Processor) modules. Each amplifier is equipped with an edge card connector inside the back panel P .I.P . compartme[...]

Page 39 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers pressors, it only compr esses the signal to prevent over - load. It can deliver up to 13 dB of additional headroom without being noticeable. ISO Programmable Input Processor (P .I .P . ) —W ARNING— THIS P .I .P . PROVIDES FULL ISOLATION FOR ISO-MODIFIED AMPLI[...]

Page 40 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers 9 Ser vice This unit has very sophisticated circuitry which should only be serviced by a fully trained technician. This is one reason why each unit bears the following label: CAUTION: To prevent electric shock, do not remove covers. No user serviceable parts insi[...]

Page 41 Studio Reference I I I I I & II II II II II Professional Studio Amplifiers Crown Factor y Ser vice Information Shipping Address: Crown International, Inc., Factory Service, 57620 C.R. 105, Elkhart, Indiana 46517 Phone: 1-800-342-6939 or 1-219-294-8200 Fax: 1-219-294-8301 Owner’s Name: __________________________________________________[...]