Crown Studio Reference I Studio Reference II User manual

PROFESSIONAL STUDlO AMPLIFIERS
Studio Referenc dio Referenee
Some models may be exported under the name Asrr@rou@
O "99 8by Crown Ir~ternatit:,nal, fnc., P.O. Box t COO, Elkhart. lndizn~i 46575-?OQO U.S.A. Telephone: 219-244-
8000. Sfudio Refere?-9c:cawplifiers are produced by Crawn fnterrsaticsnal, Inc, xr'radernark Notice: Skrdio
Reference'* and Gronnd~d &!.idge7" are tradcrnarks and Amcnm:'@ &IrcswsT 10C? ODEP IQ S,ysl'cm.e" and
&"i.PF are registered trademarks trf Crcwn BntsrnationaY, Irx. Blher trademarks are the properv of their
respeclive owrwrs.

@Krawn"
--,,,
Stlidio Refgrence Service Manual
, , , .-. -""..."" R~K
6
*-....-
The information furnished in this manual does not Include all of the de"iaifs sf design, production, or variations of
the equipment. Nor does it cover every possible 8itua"ii~n which may ariss during installation, operation sr
maintenance. if you need special assistance beyond the scope of this manuas, please eontact the Crown
Technical Suppart Group,
Mai/: P.0. BQX 4008 Elkhart lN 465?5-1000
Sbippin-ag: Pit. 2 S,W,, 171 8 W, Mishawaka Rd., Elkhark EN 4651 7
Phone: $800) 342-6939/(2 1 9) 294-8206
FAX: $2 "19) 294-8361
Web: ~w~cPQw~~u~~~~co~
TO PREVEMT ELECTRlC SMOCK 80
NQT REMOVE TOP OR BQnDM
COMERS. NQ USER SERVICWBLE
. PARTSINSIDE, REFER SERVOCtNC
TO QUALIFIED SERVICE
PERSOMNEL* DISCONNECT
POWER CORD BEFORE REMOVING
RmR ENPUT MODULE TO ACCESS
GAIN SWITCH,
A PR~VENIR LE CHOG
~LECTRIOUE N'ENLEVU
PA8 LES CQUVERTURES,
RlEM DES PART lES
UTlLES A L"INT~RIEUR,
D~BRANCHER u BORNE
AVANT DWUVRIR U
MODULE EN ARRI~RE.
f 0 REDUCE THE RISK OF ELECTRIC
SHOCK, DO NOT EXPOSE THlS
EQUIPMENT TO RAIN OR MOISTURE!

Rev. Q 12-98 Initial Printing

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Rev 8
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Studio Reference Service Manu3l @crown
1 Bntroductisn ................................................................................................... 3-1
........................................................................ 1. 1 The Stndis Referents
1-1
1.2 Scope ................................................................................................ 1-1
............................
1.3 Warranty .~.~~~~~...~.~..A~~~~~....,......... 1-1
2 Specifications ................................................................................................ -2-1
2 . "Berformance ......................................................................................2. 1
2.2 Pswei ................................................................................................. 2-1
23 Cantrofs ............................................................................................. 2-2
2. 4 f ndicators .......................................................................................... 2.2
......................................................................................
2.5 l~putsautput 2-3
2.6 Output Signal ..................................................................................... 2-3
22 Protcctisn .......................................................................................... 2.3
2.8 Construction ...................................................................................... 2.3
3 Va1tags Conversion ........................................................................................ 3-1
.................................................................................................
4 Circuit Theory 4-4
...........................................................................................
4.1 Overview 4-1
4.2 Features ............................................................................................. 4-2
4.3 Frant End Operation .......................................................................... 4-2
4.3.1 Balanced Gnin Stage (BGS) ..................................................... 4-2
4.3.2 Variable Gain Stage (VGS) ........................................................ 4-2
4.3.3 Error Amp .................................................................................. 4.2
4.4 Voltage Amplification ......................................................................... 4-2
4.4.1 Voltage Transfators .................................................................... 4.3
.................................................. 4.4.2 bast Voltage Amplifiers (LVAS) 4-3
...............................................................
4.5 Grounded Bridge Topology 4-4
......................................................................... 4.5. Wigh Side (HS) -4-4
4.5.2 Law Side (LS) ............................................................................ 4.4
....................................
4.6 Output Device Emulation Prccalectian (OBEP) 4-5
4.7 Ganliol Circuitry ................................................................................ 4-6
4.7.1 DC$LF Protect ............................................................................ 4-6
4. 7.2 fault Circuit ............................................................................... 4-6
4.7.3 Turn On Belay ........................................................................... 4-6
................................................................................
4.7. 4 Fan Corjtrol 4-6
4.8 Power Supply .................................................................................... 4-6
4.8. 1 AC kine Fiiter ............................................................................ 4-6
423.2 Soft Start ................................................................................... 4-6
4.8. 3 Over Voltage Protection ............................................................ 4-7
.............................................................................. 4.9 Display Circuitry "4-7
............................................................................................
4.9.1 1QC 4-7
4"9+2 ODEP ........................................................................................ 4.7
........................................................................
433 Signal Indicafis~s 4.7

.......
........................................................................................................... "
5 Electrical Checkout and Adjustment Procedures ,,, ....................................... 5-1
51 General Informatiow ........................................................................... 5-1
52 Standard Initiat Conditions ................................................................ 5-1
53 DC Offset .......................................................................................... 5-1
5.4 Output Bias Adjustmen$ .................................................................... 5-1
55 OBEP Voltage Adjustment ................................................................. 5-1
5.6 AC Pawer Draw ................................................................................. 5-1
5.7 High tine Gutsue ................................................................................ 5-1
5-8 Common Mode Wejects'sn .................................................................. 5-1
5.9 Voltage Gain ...................................................................................... 5-2
533 Level Controls ................................................................................. 5-2
5. 1 1 Current bimi "r .... ............................................................................... 5-2
512 Slew Rate and *a OK Square Wave .................................................... 5-2
. ..........*<."...........................................................................
5 f 3 Crosstalk 5-3
5. 1-4 Output Power ................................................................................... 5-9
5.1 5 Reactive Loads ................................................................................ 5-3
5. 16 ODEP Limiting ................................................................................. 5-4
5% 17 Mute and Turn-On Delay .................................................................. 5-4
5. 18 Law Frequency Protection ............................................................... 5-4
5. 19 Signal to Noise Ratia ....................................................................... 545
5.20 Intermadulation Diskoflion ............................................................... 5-5
5.21 LED Functions ................................................................................. 5-5
5.22 Display Set-Up ................................................................................ 5-5
5.23 Turn-On Transients ........................................................................... 5-5
5.24 Turn-OM Transiep-rts .......................................................................... 5-5
525 Past Testing ..................................................................................... 5-5
6 Schematics .................................................................................................... 6-1
7 Parts Information ............................................................................................ 7-1
7. 1 General lnfarmation ........................................................................... 7-1
7.2 Standard and Special Parts ............................................................... 7-1
7.3 Ordering Parts ................................................................................... 7-1
........................................................
....................
7.4 Shipment .....,. 7-1
7.5 Terms ................................................................................................. 7-7
..
7.6 Illustrated Parts List ....................... ., ,.,, ................................ 7-1
.........................
................... Figure 7.1 Front Panel Exploded View ,.. 7-2
...................................... Figure 7.2 Top Main Assembly Exploded View
7-4
Figure 7.3 Bottom Main Assembly Exploded View ................................ 7-6
Figure 7. 4 Back Pans[ Assembly Exploded View ....... ., ........................ 7-8
Fi%jure 7.5 Output Assembly Exploded View ....................................... 3-1 61
Figt,i re 7% Capacitor Assembly Exploded View ................................... 7-12?
Figure 7. 7 PIP Cage Assembly Exploded View ................................... 7-15

R@K 0
. -.., _____ylll~1~1111__ . , ,
Stvd8"~ Reference Service Manuai @CrQWne
P, ,,
P
.................................................
8 Module information ........................................................................................ 8-4
8.1 General information ........................................................................... 8-4
8.2 Studia Reference 1 Module lnfsrmatisn ............................................. 8-1
............................................ 8.3 Studio Reference If Module Infsrmatisn
8-1
8-4 Q.4397 1-6 Main Module ........................ ... .. , .................................. $3-2
85 Q43369-0 Outp&r"lodeelie .................................................................. 8-8
8.6 Q43183A3 Control Module .............................................................. 8-11
8.7 Q43.450-8 Control Module ............................................................... 8-14
8.8 843584-2 Control Module ............................................................... 8-17
8.9 a4301 8-3 Display Modu8e ............................................................... 8-20
8.1 Q 64331 1-2 Main Module ................................................................. 8-23
.............
8.1 1 Q43388-0 Main Module ................... .... ..,,.. ,.,
8-28
8. t 2 Q43389-8 Butput Module .............................................................. 8-33
8.13 a4331 2-0 Display Module ............................................................. 8-36

@crowne
P -..".. .......- , , , ,
Studio Reference Service pw Manusf R~K 0
P
P
Figure 2.1 Studio Wefsrence Dimensions ......................................................... 2-3
Figuss 3.1 Specific Voltage Wiring ................................................................... 3-1
Figure 32 Circuit Breaker Selection ...... .............,... ...................................... 3-11
Figure 4 . t Simplified Studio Refereilea Biock Diagram ................................... 4-1
Figure 4.2 Simplified Ampiitier Front End and Voltage Ampiifiication Stages .. 4-3
Figure 43 Simpfified Grounded Bridge ................... ,..... .............................. 4-5
Figure 5. 1 Differentiatar Circuit ........................................................................ 5-2
figure 5-2 Differentiated Square Wave .............................. ..,,,,..*+.+'......... 5-2
................................................
Figure 53 10 kHz Square Wave ................... ...
5-2
Figure 5. 4 inductive Load CoId ........................................................................ 5-3
Figure 5. 5 5~nd~etive Load Warm ...................................................................... 5-3
Figure 56 Tartup@ Yest Waveform ..................................................................... 5-4
Figure 5-4 OBEP Limiting Waveform ..................................................................... 5-4
Figure 7. 1 Front Panel Parts ............................................................................. 7-2
Figure 4. 2Top Main Assembly Parts ................................................................ 7-4
Figure 7.3 Bottom Main Assembly Parts ....................... .................................. 7-6
........................
....................
Figure 7. 4 Back Panel Assembly Parts ......... 7-8
................... ........................................
Figure 75 Output Assembly Par& ,. 7-16
Figure 73 Capacitor Asssmbly Parts ............................................................ F.12
Figure 72 PIP Cage Assembly Parts ............................................................. 7-14
Figure 8. 1 a43371 -6 Main Msdule Map .......................................................... 8-7
Figure 8.2 Q43363-8 Output Module Map ..................................................... 8-18
Figure 823 Q43383A3 Control Maduis Map .................................................... 8-13
Figure 8.4 Q843458-8 Control Madula Map ..................................................... 8-16
Figuse 825 Q4J5Q4-2 Control Module Map ..................................................... 8-19
Figuw 8. 6 64381 8-3 Bispray Module Map ..................................................... 8-22
Figure8.7 a4336 1-2 Main Module Mag .................... ...... .............................. 8-27
figure 8.8 843388-0 Main Module Map ........................................................ 8-32
Figure 83 043389-8 Output Modube Map ..................................................... 8-35
Figurs 8'16 Q43312-0 Display Msduls Map .................................................. 8-38

t .I Ths Studia Referenee
The Studio Reference amplifiers are the flagship sf
Crown Internatfsna\. They oRsr the best in sound re-
production with a dynamic range capable of accurately
reproducing 20-bit digital recardings. Super low har-
monic and intermodulation dis$or$ion provides the best
transfer function in the business. And the ultra-high
damping factor af 20,000 detivsrs superior foud-
speaker motion control for a tight and clean low-end.
1.2 Scape
This massr_eaI contains sewice information for the Grown
Studio Reference power amplifiers.. It ia designed I~P
be used with the appilcable Reference Manual' How-
ever, some important information is duplicated in this
Servica Manual in case the Reference Manual is not
readily availabls.
This Service Manual includes severaB sections, These
sectiians include Sp~cifications, Vottag~ Conversion,
Circuit Thssry? EEfectrieal Che~kout, Parts Information,
Module Information, aod Exploded View Drawings,
Schematics are included. Note that a Mexdu%e is com-
prised a$ the circuit board with the component parts
instal!@d. Crown does not sell blank (unpopulated) cis=.
cuiQ boards.
CAUTIOH: TRs infermatien in this manual Is Intsndsd to b~
ossd by an exparlenc%d t@~hnlclaa only h
1.3 Warranty
Each Reference Manual contains basic pslieies as re-
fated to %he customer. In addition, it should be staked
that this ssrviee dacumentalisn is meant ts be used
snl y by properly trained service personnel. Because
most Crawn products carry a 3 Year Full Warranty (in-
ciud~ng round trip shipping within the United States),
aft warranty service should be referred to the Crown
Factory or Authorized Warran& Sewice Center. See the
applicablsOwner's Manual for warranty details, To find
the iocation QI the nEarsst Authorired Sarvice Center,
or to obtain instructions fcar receiving Crown Factory
Service, piease contact tho Crown Technical Support
Group (within North Amerrca) or your Crown/Amcrg;bn
Importgr (outside North America),
Plant 2 S.W,
171 8 W. Mishawaka Bd,
Elkhaa, IN USA 4651 '7
Phone: [phone]
Tall Free: (8QO) M2-6939
FM: (21 9) 294-8301
Web: .er~wnaudis~com
Introduction t -7

Sf ~dio Reference Service Manual
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introduction 4 -2