M466 — Compressor - Limiter

8-109 AMPLIFIER_SERIES The 8-109 serics 0f amplifiers are utilized a$ an internal component within various WBS scries 0 f audio conso | e modules . Each 8-109 amp] i fier mounts a$ plug-in assembIy onto the mo dule motherboard The 8-109 amp]ifier provides an actively balanced output with +30 dBm capability . It i5 employed a $ n output or booster amp]ifier with either ba ]anced or an unbalanced input . The following specifications apply to the 8-109 series 0 f amp]ifiers Unit Input Ba ]anccd Unba Tanced Ba ]anced Ba Tanced Unbalanced Ba ]anced Ba lanced Ba lanced Gain 8-109 8-109A 8-1098 8-109c 8- 1090 8- 109E 8-109F 8-109G 15 dB 7 dB 18 dB 39 dD 29 dB 29 dB 33 dk 23 dB Frequency Response: +0 . 2 dB from 20 Hz to 20 kHz. Noisc: -108 dBm EIN from 20 Hz to 20 kHz . Ha rmonic Distortion: Less than 0 .13 THD from 20 Hz to 20 kHz a t +30 dBm output (typically Tess than 0 . 02% at mid-band) Source Impedance: 600 ohms or Tess , balanced 0r unbalanced_ Input Impedances: Models with balanced input: Sk ohms minimum. 8-109A: 30k ohms 8-1090: 4700 ohms Input Levels: Depending on gain of particular mo de 1 and system operating Teve] s (Kefer to gain specifications above . ) 8-109-1-1

WARD-BECK SYSTEMS LTD

8-109 AMPLIFIER_SERIES Output Impedance: Load Impedance: Less than 100 ohms 600 ohms ba lanced_ Output Level : +30 dBm maximum_ Power Requirements: +21.5 volts dc 18 MA quiescent current, 65 mA at +30 dBm output. Ambient Temperature: 0 to 60 degrees Celsius Dimensions: 3.25" X 3,38" X 0 .57" (83 MM X 86 Mm X 15 mm ) Thc 8-109 comprises two amplifier sections one consisting 0 f Z1 with Q1 through Q4 , and the other 0 f 22 with Q5 through Q8 _ The Tinear integrated circuit 21 opera Les a5 preamplifier and buffer stage to drive the trans is tor output amplifier section. In the ma jority 0 f the 8-109 models , the inputs 0 f the two amplifier sections are interconnected 4$ cross coupTed di fferential pair to provide balanced input AI ternately , in thc case 0 f the 8-109A and D , single-ended , unbalanced input is used Thc balanced input yields scvera] input characteristics s imilar to thosc 0 f an input transformer Output Teve] rema ins constant when the input i5 fed from either balanced or an unbalanced source Good common mode rejection i$ another feature 0 f this type 0 f inpul configuration For amplifiers operating in the ba lanced mo de the value 0 f R15 cstablishes the feedback ratio 0 f the two amp]ifier sections and thus controIs the amp]ifier gain_ When utilized in thc unbalanced arrangement the Tower amplifier section (Z2 with Q5 through Q8) i5 used a $ the input seclion , with the input s igna] appiied to pin E2 _ Amplifier gain is determined by the va lues 0 f R6 and R1l One ha ] f 0 f the balanced output signa] appears at pin E6 _ The upper ha ] f 0 f the amp]ifier (Z1 with Q1 through Q4 ) operates as unity ga in 8-109-1-2

WAAD-BECK SYSTEMS LTD_

8-109 AMPLIFIERSERIES inverting amp]ificr with El externally strapped to E6 The output 0 [ a 11 mO de ] s 0 f the 8-109 series is actively ba ]anced and is brought out at pins E4 and E6 . 8-109-1-3

WAAD-BECK SYSTEMS LTD PARTS LISI 8-109 AMPL [ FIER SERIES 8-109 PART

6-106 COMPRESSOR_CONTROL AMPL [FIER The 6 - 106 contro] amplifier is printed circuit board unit des igned to bc used a $ d interna component 0 f the WBS M466 compressor/] imiter module The 6-106 mounts onto the M466 motherboard a5 plug-in unit The 6-106 Wil] accept two separate dc.input voltages one is used to control the compressor action , the other to contro] the Timiter action 0 f the M466 COMPRESSOR VOLTAGE PROCESSING: The dc signa) generated by the compressor amp]ifier and detector 0 f the M466 is fed to termina | EII of the 6-106 amplifier Z| Torms high-impedance buffer amplifier which in turn drives thc release contro] amplifier 22 The compressor release contro] i5 connected between termina]s E] and E2 _ IL determincs the rate 0 f discharge of capacitor C3 after s igna] remova 1 22 i$ fo ] owed by 23 , which is des igned to operae a5 logari lhic amp]ifier Thus Tinear input voltage change will result in Togarithmic vo | tage change operating the compressor attcnuator In this fashion , if plotted on dB sca]e, Tinear compression $ Tope i s achieved Fo]0w ing the logarithmic amp]ifier is 24 , which acts a $ summing amplifier for both the compressor a $ wel] a5 thc Timiter function . The compressor Tope is adjusted by changing the ga in 0 f 24 using different resistor va lues across termina 1 s E14 and E15 LIMITER VOLTAGE PROCESSING: The dc voltage generated at the output o f the Timiter ampli fier and detector 0 f the M466 i5 fed to termina] E12 0 f the 6 - 106 contro] amplifier 6-106-1-1

WAAD-BECK SYSTEMS LTD DESCRIPIION 6-106 COMPRESSOR CONTROL AMPLIFIER 25 provides the Timiting action . The output 0 f 25 i5 sumed via RI8 to 74 It a ]50 appears a L termina1 E13 , where it 1s used to operate two voltage comparators (part 0 [ 29 ) and fina]Iy drive the two LED 1imiter indicators. 26 is designed a $ variab]e impedance amp]ifier controlling the effective impedance across R2/ and therefore the Timiter release time Input control 0 [ 26 i$ affected by the Timit release contro] connected across termina] s E3 and E4 . A +16 volts dc supply vo]tage i5 applied to pins ES , E6 and E7 6-106-1 -2

WAAD-BECK SYSTEMS LTD PARIS LIST 6-106 COMPRESSOR CONTROL AMPLIFIER PART

8-109 AMPLIFIER_SERIES Output Impedance Less than 100 ohms Load Impedance 600 ohms balanced _ Output Leve) : +30 dBm maximum_ Power Requirements: +21.5 volts dc, 18 MA quiescent current, 65 mA at +30 dBm output Ambient Temperature: to 60 degrees Celsius Dimensions 25" (83 Mm 38" 57" 86 mm X 15 mm ) The 8-109 comprises two amplifier sections , one cons isting 0 f Z1 with Q1 through Q4 , and the other of 22 with Q5 through Q8 _ The Tinear integrated circuit L1 operates a5 preamplifier and buf fer stage to drive the transistor output amplifier section.

In the majority 0 f the 8-109 models the inputs 0 f the two amp]ifier sections are interconnected as cros 5 coupled differentia] pair to provide ba |anced input Alternately , in thc case 0 f the 8-1094 and single-ended , unbalanced input i $ used_ Thc balanced input yields scvera] input characteristics s imiar Lo thosc 0 f an input trans forie Output Teve] rema ins constant when the input is fed from either ba lanced or an unbalanced source Good common mo de rejection 1 $ another feature 0 f this type 0 f input configuration .

For amplifiers in the ba ]anced "Reeabice mode the va]ue of R15 cstablishes the ratio 0 f the two amp ifier sections and thus controIs the amp]ifier ga in. When utilized in thc unbalanced arrangement the Tower amplifier section (Z2 with Q5 through Q8) 15 uscd as the input section , with the input s ignal applied to pin E2 _ Amplifier gain is determined by the vaTues of R6 and Rll One ha] f 0 f the balanced output 5 igna ppears at E6 .

The 8i5 upper ha ] f 0 f the amp]ifier (Z1 with Q1 through operates as unity ga in 8- 109-1-2

M466 COMPRESSORILIMITER Ga i n: Unity _ Make up ga in 0 f 16 dB maximum is avai lable in compression mode only . +0.25 dB from 20 Hz to 20 kHz _ Frequency Response: Noise: At -10 dBm sensitivity: 72 dB below -10 dBi . At 0 +4 or +8 dBm sensitivity: 75 dB be /ow selected sensitivity setting: (Bandwidth 20 Hz to 20 kHz ) Harmonic Distortion: Less than 0 . 57 ThD from 30 Hz to 15 kHz a L 28 dBm output or less wi th 10 dB 0 f compression and/or Timiting Les5 than 0.1% at compressor or Timiter threshold Mcasured with sensitivity switch at +8 and release contro ] s at maximum (i.e_ fully clock wise) Sourcc Impedance: Input Impedance: Input Level: 600 ohms maximum , ba Tanced / unbalanced_ 30k ohms t108 _ baTanced -10 dBm to +8 dBm nomina ] +30 dBm ma x imum with sensitivity set at 0 _ Less than 100 ohms +108 , ba lanced_ Output Impedance: Load Impedance: 600 ohms , ba Tanced Output Level: -10 dBm to +8 dBm nomina] 128 dBm ma ximum Compression Ratio: Selectab]e , 1.5:1, 2:1 , 3:1 , 5 :1 (in dB) 50 : 1 (in dB ) _ Limiting Ratio: Compress ion Range: Greater than 30 dB _ Attack Time : Compressor: 10 m$ internally adjustab]e . Limiter: 50 u5

WAAD-BECK SYSTEMS LTD IECHNICAL DATA M466 COMPRESSORLLIMITER Rccovery Time: (From 10 dB 0 f ga in reduction) Compressor: 0 . 2 to 5s Limiter: 0 .1 to 5$ De-ess ing: Operates d5 frequency dependent com- pressor 3 dB point adjustable from kHz to 6 kHz . Phasing: Low number termina] s of input and out- put are in phase . Metering: Provision for externa] VU meter to mon - itor gain reduction or output Teve] 125 volts dc , 100 ma maximum Power Requirements: Ambient Temperature: 0 to 60 degrees Celsius Dimensions: 6 " wide 7" high 6 .5 " deep (41 MM X 178 MM 165 mm ) Accessories: M466M Meter Module M467 Noise Gate and Me er Module 1-2

WAAD-BECK Systems LTD

M466 COMPRESSORILIMITER Ga in: Unity . Make up gain 0f 16 dB maximum is ava i Tab]e in compression mode only . Frequency Response: +0.25 dB from 20 Hz to 20 kHz _ Noise: At -10 dBm sensitivity: 72 dB below -10 dBm At 0 +4 or +8 dBm sensitivity: 75 dB below selected sens itivity setting _ (Bandwidth 20 Hz to 20 kHz ) Harmonic Distortion: Less than 0 .

5% THD from 30 Hz to 15 kHz at +28 dBm output or Tess with 10 dB of compression and/or Timiting Less than 0 . 1% at compressor or imiter threshold _ Measured with sensitivity switch at +8 and release contro]s at maximum (i.e_ fully clock wise) Source Impedance: 600 ohms maximum , ba Tanced/unba lanced_ Input Impedance: 30k ohms +10% ba lanced Input Level : -10 dBm to +8 dBm nomina ] +30 dBm maximum with sensitivity set at 0 Output Impedance: Load Impedance: Less than 100 ohms +10% ba lanced_ 600 ohms balanced _ Output Level : -10 dBm to +8 dBm nomina ] +28 dBm maximum, Compression Ratio: Selectable , 1.5;1, 2:1, 3 : ] , 5 :1 (in dB ) Limiting Ratio: 50 :1 (in dB ) _ Compression Range: Attack Time: Greater than 30 dB _ Compressor: 10 MS , internally adjustable Limiter: 50 us , 1-1

M466 CQMPRESSORLLIMITER Recovery Time: (From 10 dB 0 f ga in reduction) Compressor: 0 . 2 to 5s Limiter: 0.1 to 5s De-ess ing: Operates as frequency dependent com- pressor dB point adjustab]e from kHz to kHz Phasing : Low number termina]s 0 f input and out- put are in phase . Metering: Provision for externa] VU meter to mon - itor gain reduction or output Teve] Power Requirements +25 volts dc , 100 mA maximum_ Ambient Temperature: Dimensions: 0 to 60 degrees Celsius 1.6" wide X 7" high 6 .5" deep (41 mm 178 Mm X 165 mm ) Accessories: M466m Meter Module_ M467 Noise Gate and Meter Module _ 1-2

M466_COMPRESSOR/LIMITER Input The input signa] is applied to pins and 2 0 f the edge con- nector The signa ] is routed directly to the noria ]Iy closed con tacts 0 f the INSERT switch SW7 Additionally the signa 1 i$ fed to input amplifiers 21 and 22 by means 0f bridging input . Depending on the position 0 f the INSERT switch, the output 0 f the M466 i$ originated either from the input or from the output 0 f the unit In this way it i5 possib ]e t0 bypass the entire compressor/limitcr circuit While still applying the input signa] to the unit therefore permitting adjustment and set-up to be ma de prior to insertion 0 f the unit into the s igna ] path. Electronic_Attenuator The input amplifiers are followed by an attenuator circuit com- prising 23 24 25 as we]1 as Q1 , Q2 Q3 and Q4 In principle, the circuit operates a $ voltage muitiplier uS ing the input signa 1 and the cuntro] voltage generated in the contro] amp]i - fier as its two inputs Transistors Q1 to Q4 are therma TTy coupled to provide good circuit stability over Targe oper- ating tcmperature range THRESHOLD Controls The output 0 f the voltage attenuator circuit is coupled via C31 to the COMPRESSOR THRESHOLD contro] SW4 to the MAKE-UP-GAIN contro] R72 and Lo the LIMITER THRESHOLD contro] SW5 via the COMPRESSOR INSERT switch Sw2c_ SENSITIVITY Switch The SENSITIVITY contro] enables the unit to operate with optimum and constant distortion and no i se specifications with varying system insert Tevels VU Meter Amplifier The VU meter amplifier (part 0 f 29 ) derives its input from constant Teve1 point in the system As result the 0 VU reading will correspond to the calibrated pos itions 0 f the SENSITIVITY switch SWI 2-1

WAAD-BECK SystemS LTD

M466_COMPRESSORZLIMITER Compressor_Amplifier and Rectificr The output from the COMPRESSOR THRESHOLD attenuator Sw4 feeds the signa ] via the DE-ESS switch SV6 and associated filter to amplifier 26 A full-wave rectifier consisting 0 f CRS and CRG follows 26 and in turn generates positive contro] voltage to opera te the compressor function 0 f the unit R5S determines thc attack time and is factory sct for 10 milliseconds . However the resistor may be varied from 2k ohms to 47k ohms to achieve other attack time charactcristics DE_ESS Control The DE-ESS circuit consists 0 f high pass filter comprising c21 RS8 and R59 With the DE-ESS function activated, only frequencies from kllz to 6 kHz and above will operate the compressor In addition SW6A reduces the release time of the compressor to approxiia tely ha] f when operated in the DE-ESS mode Both thesc mcasures combined cause the unit t0 be sensitive onTy to the high frequency components 0 f sibilant voice material Limiter Amplifier and Rectifier The output from the LIMITER THRESHOLD attenuator Sw5 feeds amp]ifiers 11 and 28 , which in turn are followed by the full wave rectifier configuration cons isting 0 [ CRTO and CRII A negative contro] voltage is thus generaled and supplied to the contro] amplifier The attack time is set at the factory to 50 microseconds and can be altered by changing the value 0 f R1og When the M466 is operating a $ Timiter only , its ma x i MUM output in dBm 15 dctcrmined by the setting 0f the SENSTT[VITY switch added a Igebraically to the setting 0 f the LIMITER THRESHOLD contro] Gain Reduction Meter_Amplifier The ga in reduction meter amplifier (part 0 f 79 , pins 12 , 13 and 14) monitors the attenuator control voltage generated in the 6 -106 contro| amplifier which appears at pin TEIO . This voltage cancels oul pre-sel bias adjusted by RI19 With no signa present thc bias is adjusted to produce 0 VU reading on an external VU meter (approx. 0 . 6v ) 2-2

WARD-BECK SYSTEMs LTD_ CIRCUIT DESCRIPIION M466_COMPRESSOR/LIMITER Limit Indicators Two voltage comparators (part 0 f 29 pins 1,2,3,5,6 and 7 ) compare the Timit monitor voltage at pin 1ET3 with two fixed voltages at pins 3 and 5 of 29 The unit is calibrated such Lhat with 6 dB peak Timi the LED {yeitowg CR!5 (green) Will Similarly CR16 Tight up will iuminate With 12 dK Timiting. peak Power Supply Decoupl ing An active power supply decoupling nelwork cons isting 0 f Q6 thru Q11 provides high degree 0 f isolation between the M466 and the +25 volt supply rails Transistors Q7 and 010 serve a$ monitors current and WiT] imit the current flowing through the transistors pass Q6 and 09 t0 approximately 150 ma_ This fcature is des igned to prevent excessivc Power supply demands on the Ma inder re- 0 f the conso ]e system in the event 0f component failure within the M466 _ 210 in conjunction with Q12 and 013 forms +16 vo]l high - slability regulator used to supply the required voltages to the contro1 amplifier 6 - 106 2-3

WAAD-BECK SYSteMS LTD OPERATINGINSTRUCTIOnS M466 COMPRESSORLLIMITER The M466 i5 des igned to operate as compressor and/or Timiter independent 0 f onc another a5 far a$ threshold , attack time and release times are concerned_ COMPRESSOR As compressor thc unit i$ capab]e 0 f compression over 40 dB input range from 20 dB below to 20 dB abovc the nomina] SENSITIVITY setling Four gain reduction SLOPES are ava i ablc , namely 1.5:1 , 2:1 3 :1 and 5:1 To iluslratc using 2:1 compression s lope 10 dB change in input Tevel will result in 5 dB change in output Teve1 Typically compressor is operated with 6 to 10 dB 0 f compres - sion This places the nominal operating point on the compres - sion s Tope In this manner , as the average input Teve] in- creases further, the increase in output eve | is proportiona |Iy reduced Conversely , as the averagc input Teve1 decreases the decrease in output Tevel 15 aso proportionally reduced The choice 0 f any given gain reduction slope in effect deter- mines the dynamic range 0 f the program ma teria] The average Tevel Tos $ resulting from thc compress ion action can be recovered at the output 0 f the unit 45 ing the MAKE-UP_ GA [ N control If hcadroom in excess of 30 dB 1$ required in particular mixing channel then thc SENSITIVITY should be set

M466_COMPRESSOR/LIMITER Input The input_Signa] is applied to pins and 0 f the edge com - nector The s igna i5 routed directly to the norma ]y closed contacts of the INSERT switch SW7 Additionally the signa] is fed to input amp]ifiers and 22 by means o f bridging` input Depending 0n the position 0 f the INSERT switch , Ehe output 0 f the M466 1 5 originated ej ther from the input or from the output 0 f the unit In this way it i5 possible to bypass the entire compressor/limiter circuit while still applying the input signa] to the unit therefore permitting adjustment and set-up to be ma de prior to insertion 0 f the unit into the signa path Electronic Attenuator The input amp] ifiers are fo]lowed by an attenuator circuit com- prising 23 24, 25 as wc] as Q1 Q3 &nd Q4 In principle , the rcuit operates voltage MU tiplier uS ing the input signd and the cuntrol Vo | tage generated in the contro] ampli- fier as its two inputs Transistors Q1 to Q4 are therma ]y coupled to prov ide good circu stability over Tarye oper- ating temperature range THRESHOLD Controls The output o f the voltage attenuator circuit is via C31 to the COMPRESSOR THRESHOLD contro] SW4 RouP-ed_ to the UP- GAIN control R72 and Lo the LIMITER THRESHOL; contro] Sw5 Via the COMPRESSOR INSERT switch SW2c SENSITIVITY Switch The SENSITIVITY con tro] enables the unit to operate with optimum and constant distortion and no ise specifications with varying system insert Teve] 5 VU Meter_Amplifier The VU meter amp]ifier (part of 29) derives its input from constant Teve1 point in the system As resu]t the 0 VU reading will correspond to the ca ibrated positions 0 f the SENSITIVITY switch SWI 2 -1

M466 COMPRESSORLLIMITER stereo tie connection Pin 10) provision made to connect the compressor contro] rcuitry o f severa1 compressors to - for the purpose 0 f stereo 8etheEhe or multi-channel operation. compressor contro] circuitry 0 f two or more units can thus be interconnected and the unit producing the highest control voltage will a5 5 ume contro] 0f &]1 interconnected units In order to produce imilar compression characteristics, SLOPE and RELEASE contro| 5 0 f a11 units should be set to iden - tica values Note that in contrast to the compressor action, the imiter action o f the individua] units are not intercon- nected and rema in independent of each other For certain production applications may be desirab]e to utilize the compressor (usua]ly operating on the 3:1 or 5 : 1 s]ope ) as Timiter in order t0 s]ightly reduce infrequent program peaks This particular mode 0 f operation requires very subtle onset 0 f compression To achieve this characteristic the compressor control circuitry Wil] ha ve be reca|ibra ted a5 outlined in the

PROCEDURE , step 24 _ LIMITER As Timiter and compressor circuits are entirely independent from each other THRESHOLD po ints and RELEASE l imes may be adjusted individually for compressor and Timiter functions . Thc LIMITER THRESHOLD contro] is adjustable in 2 dB steps up to 20 dB above the nomina 1 SENSITIVITY setting. With 50 :1 compression s]ope the setting 0 [ the THRESHOLD control deter- mines the upper headroom Timit 0 f the audio signa| being passed through the unit. When the Timiter i5 operating , the MAKE-UP-GAIN contro1 a $ described earlier is disabled . The amount 0 f peak Timiting action taking effect 1$ shown 0n two LED indicators The first LED (green) Tights up at 6 dB and the second one (yellow) a L 12 dB Timiting. If 12 dB 0 f peak Timiting persists the Teve] in the channel being con- trolled i$ abnorma ]Iy high and should be adjusted accordingly , either by changing SENSITIVITY or FADER settings 3 - 2

WAAD-BECK SYSTEMS LTD; 1 ] 0 3 3 { 3 5 3 8 5 1 5 6 5 L 1 1 1 8 3 1 1 5 1 9 5 1 39 6 ; 1 5 ; 2 1 { 2 7 5 { 1 d: 8 2 11 1 1 1 3 8 { ; 2 7 3 5 1 2 5 1 0 2 8 W@P Indino 4-

WARD-BECK SYSTEMS LTD_ 8 { 1 S ] { 1 8 1 8 Kh 8 6 ; 5 0 1 Ul 8 9 | 1 1 { 1 8 8 2 8 W#p Ind[O 4-2

WAAD-BECK SYSTEMS LTD ADJUSTMEnT PROCEDURE M466 COMPRESSORLLIMITER Reference_Drawings: 8466-01-001 B466-02-001 B466-06- 001 B6-106-02-001 B6 - 106-06-001 B8 - 109-02-005 B8 - 109-06-005 4466-04-001 M466 Functiona] M466 Schematic M466 Component Layout 6 - 106 Schematic 6-106 Component Layout 8- 1090 Schematic 8-1090 Component Layout M466 Connector Layout Notes: 1 ) Use SImPSON DVM type 464 or equivalent For 411 dc voltage measurements 2 ) In the interest 0 f s implicity a11 front pane] contro] $ described dre identified by the terms and abbrevialions used on the aclud] panel 1 ) Remove cards 8-1090 and 6-106 Release INS switch 2 ) Apply power and check: ~Tota] supply currenl approximately 21 ma -Voltage at pins 2E3 and 2E7 : 421 . 0 V to +21 .5 V -Voltage at pins TES and 1E7 : +16 V +0/-0.5 V 3 ) Check fo]owing points for dc voltage 4 $ indicated: 21 22 23 24 pin 6 : 25 pin 6 : 0 V 26 pin 6 : -3.3 V 26 pin 6 : 0 V 27 pin T : pin T: 0 V pin 7 : 0 pin 6 : 0 28 29 pin 6 : 0 V pin 8 : +0 6 V 4 ) ~Connect test c]ip a5 shown on drawing B466-06-001 between 1E9 TEIO and TES ~Plug in 8-109D ampl ifier Tota] supply current should rise to approximately 40 MA 5 -1

WAAD-BECK SYSTEMS LTD_

PROCEDURE M466 COMPRESSOR/LIMITER h) ~Increase input Teve1 to 20 dBm . Output Teve1 should increasc another 3 . 3 dB for tota 1 0 f 10 dB Note: If test equipment cannot supply this range 0 f input Tevels adjust COMP THLD to 20 and eslablish initia] threshold at -30 d Bm . 1) ~Chcck the 1.5:1 , 2:1 and 5 :1 compressor s]opes _ Errors should be within 10 .5 dB j ) Check compressor rclease: -Set SLOPF 3 :1 ~Set RLS (COMP ) sec -From thc threshold Teve1 increase input by 20 dB ~Switch input Teve1 back j0 dB Output Teve1 should take sec *1 sec t0 recover Adjust R14I ~Set if necessary RLS (COMP _ to 0 . 2 sec . and repeat a $ abovc . 16 ) Check de-ess circuitry a ) Set contro]s a5 fo] ows : -SENS -10 ~LIMIT THLD 0 -RLS (LIMIT) mid-position ~LIM out -DS SwiTciI in ~DS CONTROL ccw (1 kHz ) MG ccw ~GR/VU out (GR ) ~SLOPE 5 ~COMP TILd ~RLS (comp ) mid-position cOMP in -Ins in b ) ~Apply kHz , -10 dBm input signa] -Increase input Teve1 by 3 dB _ GR meler should start to show ga in reduction ~Reduce frequency 0 f input signa 1 to 500 Hz GR meter should return to origina] 0 read ing _ -Return to kHz , -10 dBm input signa | Increase frequency 0 [ input signa] and watch for GR meter to show ga i n reduction . 5-5

WAAD-BECK SYSTEMs LTD_

PROCEDURE M466 COMPRESSORZLIMITER c ) ~Repea t above steps wilh DS contro] sct fully CM and input frequency at 6 kHz . d ) Set contro]s a 5 fo]1ows: ~SENS ~LIMIT THLD ~RLS (LIMIT) ~LIM ~DS SwITcH ~MG GR/VU ~SLOPE ~cOMP THLD ~RLS (COMP ) COMP -InS 10 0 mid-position out out ccw out (GR ) 3 mid-position in in e ) ~Apply kHz , -10 dBm input signa] _ ~Note output Tevel -Turn MG contro] fully cM Output Tevel shou ]d increase by 16 dB +1 dB 17 ) Check GR meler function: -Set SLOPE to 5 : 1 ~From the threshoid point increase the input Teve] by 10 dB GR meter shou ld deflect downward Lo read approximately halfway between -7 and -10 , 18 ) Limiter adjustments a ) Set contro]s a $ foulows : ~SENS ~LIMIT THLD ~RLS (LIMIT) ~LIM ~DS SWITciI -MG ~GR/VU ~SLOPE -comP THLD ~RLS (COMP ) 10 0 mid-position in out ccw oul (GR ) 3 0 mid-position 5-6

WAAD-BECK systems LTD ADJUSTMENT_PROCEDURE M466 COMPRESSORLLIMITER COMP -INS out in b ) ~Apply kHz , -10 dBm input s i gna 1 ~Adjust RI01 (on motherboard) for 0 . 25 dB drop in output Teve] ~Increase input Tevel to +10 dBm , output should increase by Icss than 0 . 5 dB _ c ) If outpul Tevel increases by 0 .5 dB or more: -Decrease input Teve1 to -10 dBm and wait for recovery. ~Adjust R25 (on 6 - 106 ) S0 output increases by 0 . 5 dB ~Re-adjust RIOI (on motherboard) for drop 0 f 0 .5 db in output Teve1 -Increase input Tevel to +10 dBm and re-chcck increase in outpul_ d ) -If increase in output Teve] is still 0 .5 dB or more , repea t (b) and (c) as needed c ) Check imiter release: ~Set RLS (LIM) Lo 5 scc -From the threshold Teve] increase input by 10 dB . ~Switch input Tevel back 1o dK ~Adjust R30 (on 6-106 ) for release time 0 f 5 sec. +1 sec _ Note: If R3O i$ moved Loo far in the cw direction , the ga in 0 f 26 will exceed unity and the output Icve1 will slowly beg in to drop . Back 0 f f from this setting. ~Sct RLS (LIM) to 0 .1 sec and repeat as above Due to the fast release speed and the relatively s]ow meter response the change in output Tevc] wil be barely noticeabie 19 ) Delete 5-7

WAAD-BECK SYSTems LTD ADJUSTMENT_PROCEDURE M466 COMPRE SSORLLIMITER 20 ) Test and adjust LIMIT indicators: -From the threshold Tevel increase input Icve | by dB ~Adjust R146 (on motherboard) S0 green LE D CRIS just switches on VoItage at 29 pin 5 is approximately 8 mV at pin 3 approximately 6 mV ~Increase inp

PROCEDURE 5466 COMPRESSORLLIMITER Reference Drawings: B466-01 688838 B6 - 06-02-00 B6 - 106-06-00 B8 - 109-02-005 B8 - 109-06-005 A466-04-001 0466 Functional M46 chematic M46 Component Layout 6 - 106 Schematic 6-106 Component Layout 8-1090 Schematic 8-1090 Component Layout M466 Connector Layout equ valent for a11 Notes: Use SImPSON DVM type 464 vo] tage measurements the interest of simp icitxfted a 11 front panel contro] s described are denti b3 the terms and abbreviations used the actua pane Remove cards 8-1090 and 6-106 Release InS switch Apply power and check: Total supply current approximately -Voltage 2E5 and RE7: 421.0 to +21.5 ~Voltage pins and +16 V +0/-0.5 Check fo ]owing points for voltage indicated: pin pin pin Pin Pin Pin pin Pin pin Pin 8: +0 .6 V Connect {esesfeflig shown drawing B466- 06-001 between IFTO and IES _ -Plug 8-1090' amp Tota supply current should rise to approximatcly MA.

WbspsCE

PROCEDURE step 24 LIMIIER As Timiter and compressor circuits are entirely independent from each other THRESHOLD points and RELEASE imes may be adjusted individually for compressor and Timiter functions Thc LIMITER ThRESHOLi control 1$ adjustable in dB steps to 20 dB above the nomina 1 SENSITIVITY With & '5048 compression s]ope the set ting 0 f the THRESHOE?: contro] deter- m ines the upper headroom imi 0 f the audio signa| being passed through the unit When the imiter 15 the MAKE-UP-GAIN "Beratied_ contro1 a $ described ear] ier The amount of peak action taking_ itheingrs€ effect is shown on two LED indicators The LED (green Tights up at dB and the second 0ne (yellow) at 12 dB Timiting _ If 12 dB 0 f peak 1imiting persists the Teve in the channe] being con- trolled abnorma Iy hi and shou]d be SENSifivitd adjusted accordingly , either by changing or FADER settings 3 -2

1'14 6 6 COMPRESSOR /L IMITER

PART DESCR IPTION HFG MFG PA RT NUMBER

C" C37 caeee t tor • 10 uf /2S V d ele te Ke_et • T390C106 M02SAS

C" C39 " • 1 u F/3 S V 22 uF/2S V " Siemens T39 08105M03 5AS 84 1 31 3 -A 5 2Z6 -Z <40 • " " " C" • 10 uF{2S V Kemet T39 0 C10 6M0 2SAS <4 2 " 47 lIF/40 V S ie mens 841 238·C7476- T C43 • 0.02 2 lIf ase tcc CQ92 -MC- 223 M " CR 1 Dio de Moto r o l a l N4 0 0 3 CR2 " " " CR ' " " " C" " " " " CR' Fairchild l N4 148

" , CR' CR7 L[O . "d ," , flV1l7 C" Diode • , lN4 14 8 , C" CR 10 " " • CRll " , , CR 12 HO. "d , , FL V11 7 CRI3 Diode , 1" 414 , 8 CR14 • CR1 5 LED . green • fl Vl1 0

CR16 H D. yell ow , FLV 4 10

01 Refe r To 6 -10 7 oa ", Q' , Q4 Q5 del e t e a .c

Q6 Transisto r Te xa s T1P 298 ps

Q7 " Nation al PN ,3S6 9 BS

Q' " " Q9 " Te xa s W

T1P 308 OlD " Nati onal PN 36 45 :// tp ht

'- 2

WARD ~BeCI( SYSTEM S LTD .

PAR TS L IS T

M4 6 6 COMPRESSOR/ LI MITER

PART DESCRIPTIO N Kro HFG PART NUMBER

Qll r ran s t s t er National P" 364 5 Q12 • • • Q13 • " •

Rl ae s t s t o r W 52: R2 R3 • • '" 15K 4 70 11. Phil i p s • • R4 • J. J • R5 J.3 • R6 • J. J • R7 • 10K " R6 • • R9 Rl O • • '" '" 100 " • Rl\ • • R12 «t a • • '" m m • • 'J< • m • R15 " 15K "

Rl ' • 15K • Rl7 • 15K • Rl. • 620 • Rl' " 15K • R20 • 620 • • • '"'" • • '" '"

M466 COMPRESSORILIMITER PART DESCRIPT[ON MFG MFG PART_NUMBER R136 RI37 R138 R39 R140 Resistor Gw 55 5kI Delete) 4k7 47k (Delete ) Philips R141 R142 R143 R144 RI45 Trim pot Resistor KW 5% 620 2kZ 2K2 220 Piher Philips PT 10 500 R146 Trim pot Piher PT 10h (2.5) 20k SWI SW2 SW3 Sw4 SWS Switch RCL Schadow WBS 11-076 WBS 11-002 WBS 11-005 WBS 11-021 Grayhill SV6 SW7 SW8 SWg Schadow WBS 11-002 RCL Schadow VBS 11-076 WB S 11-005 Integrated circuit Na tiona] LMJOIAN 4 LMI458N 76 28 LMJOIAN Z30 LM348N LM376N Attenuator Assy WBS 6-107 WBS recommends the use 0 f replacement parts made by the specified manufacturers for continued optimum equ pment performance 6 -7

8-109 AMPLIFIER_SERIES 8-109 PART DESCRIPIION MFG MEG_PART_NUMBER R4 R5 R6 R7 R8 Resistor #W 5% 6K2 6K2 6K2 18k 18K Philips R9 R10 R1l R12 R13 16k 2k 16k 2k 390 R14 R15 R16 R17 R18 390 delete 22k 4K7 22k R19 R2O R21 R22 R23 22 470 nom 4K7 4K7 22k factory selected R24 RZs R27 R28 4K7 22k 470 nom 4k7 factory selected R29 R30 R31 R32 R33 4K7 Resistor IzW 53 6 .

& R34 R35 Resistor %W 5% 8-109-2-2