Audio Distribution Circuit

P.O.Box 3073 Pinegowrie 2123 Gauteng South Africa Tel: +27 11 838 0620 Fax: +27 11 838 0625 e-mail: [email protected] www.soundfusion.co.za

Soundfusion (Pty) Ltd. Co. Reg. No. 19940095870

TECHNICAL MANUAL STEREO AUDIO DISTRIBUTION AMPLIFIER MODULE E-234

Stereo Distribution Amplifier Amplifier Module E-234

GENERAL DESCRIPTION The E234 audio distribution card has been developed to complement the Soundfusion range of audio distribution amplifiers. The card evolved from the local industry standard, the Sound fusion E230. The card is essentially a one stereo input and 6-output 6-output distribution amplifier, but can be configured by means of jumpers to provide the following options: a) b) c) d)

One stereo input, six stereo outputs. One stereo input, five stereo outputs, 2 mono outputs. One stereo input, twelve mono outputs. One mono input, twelve mono outputs.

The two inputs are balanced, high impedance and feed through to the twelve output stages, which are each driven by a dual operational amplifier capable of driving 600 Ω loads. There is a level adjustment for left and right channels at the front of the card. Individual outputs are not adjustable. The circuit is fully balanced throughout and is powered by on board DC regulation as indicated by two LED’s at the front of the card.

Stereo Audio Distribution Amplifier – Module E-234

CIRCUIT DESCRIPTION Input: The two input stages consist of U1, U2 that provide a symmetrically balanced input. The low frequency roll-off point of 4Hz is determined by Cl, C2, R2, and R3. The high frequency roll-off is set by C3, R4 and C4, R5 at 80KHz. This point can be altered by increasing or decreasing C3 and C4 . Output level is adjusted by P1 and P2. The output of this stage appears at J1 where it can be routed to the distribution buses, left or right. The left and right signals also feed U3 that acts as a virtual earth-mixing amplifier. This creates a mono signal that can be linked via J2 and J3 to outputs 6, or all outputs. Output: Each output stage consists of a dual op amp which is capable of driving reactive loads, as occur in long cable runs, to greater than +l2dBu. The input stages are directly coupled to the output stages, thus eliminating blocking capacitors, which are detrimental to the sound quality of the signal. This is possible due to the low offset of the devices used. There is no individual adjustment of the output stages but R29 (CH1L) may be changed to obtain a different output level if necessary. The output impedance is set at 20 Ω by R32, R33. Power: The card is supplied with unregulated ± 22 VD C at pins 2 and 3, which is fed to the adjustable voltage regulators Ql Q2. There is pre-regukition decoupling with C55, C 56 56. The regulated voltage ± 16 VDC is determined by R123, R124, R125, and R126 and smoothed by C59 - C62. The LEDs LDI, L2 give on board indication of the DC condition.


STEREO AUDIO DISTRIBUTION AMPLIFIER MODULE E-234 COMPONENT LAYOUT

Stereo Audio Distribution Amplifier Module E-234 Component Layout

0V -V +V +V 1L

1R

2L

2R

3L

3R

4L

4R

5L

5R

6L

6R

IN-L

SOUNDFUSION

IN-R J3

C16

C20

C24 C24

C28 C28

C32 C32

C36

R39

R55

R71

R87

R103

R119

R41

R57

R73

R89

R105

R121

R42

R58

R74

R90

R106

R122

R36

R52

R68

R84

R100

R116

R35

R51

R67

R83

R99

R115

R40

R56

R72

R88

R104

R120

R37

R53

R69

R85

R101

R117

R38

R54

R70

R86

R102

R118

C15

C19

C23

C27

C31

C35

U5

U7

U9

U11 U11

U13

U15

C44

C46

C48

C50

C52

C54

C14

C18

C22 C22

C26

C30

C34

R31

R47

R63

R79

R95

R111

R33

R49

R65

R81

R97

R113

C43

C59

R34

R50

R66

R82

R98

R114

R28

R44

R60

R76

R92

R108

R27

R43

R59

R75

R91

R107

R32

R48

R64

R80

R96

R112

R29

R45

R61

R77

R93

R109

R30

R46

R62

R78

R94

R110

C13

C17

C21

C25

C29

C33 C33

U4

U6

U8

U10

U12

U14

C42

C45

C47

C49

C51

C53

C62

C60

C61

J2 C1

+

C2

C6

C7

+ C12 C57

R123

+ C58

R125

+

R1

R2

R13

R11 R11

R4

R3

R12

R14 R14

C3

C8

C5

C10

R7

R17

R9

R19

R6

R16

R5

R15

U2

U1

R18

R8 C56

Q2

Q1

D2 D1 C55 C55

R10

R20 C37

C38

C39

C40

C9

C4

R26 R23 R24

U3 C41 R21 R22 R25 C11

R124 R127 R126 R128

ADA 234 234 LD1

LD2

P1

J1

P2

Stereo Audio Distribution Amplifier Module E-234

STEREO AUDIO DISTRIBUTION AMPLIFIER MODULE E-234 PARTS LIST

PARTS LIST

Audio Distribution Amplifier Module E-234 Reference

Value

Description

R

1

20k

1/4 W 1 % metal film

R

2-7

l0 k


R

8-9

lk


R

10

120R


R

11

20K


R

12-17 12-17

l0 k


R

18-19

lk


R

20

120R


R

21-24

l0k


R

25-26

5k1


R

27-28

100R


R

29

lk2


R

30-31

2k2


R

32-33

10R


R

34

10K


R

35-36

100R


R

37

lk2


R

38-39

2k2


R

40-41

10R


R

42

l0 k


R

43-44

100R


R

45

1k2


R

46-47

2k2


R

48-49 48- 49

10R


R

50

10K


R

51-52

100R 100 R


R

53

1k2


R

54-55

2k2


R

56-57

10R


R

58

10K


R

59-60

100R


PARTS LIST

Audio Audio Distri Distribut bution ion Am Am lifier lifier Module Module E-234 E-234 Reference

Value

Description

R

61

1k 2

1/4W 1% metal film

R

62-63

2k2

1/4W 1% metal film

R

64-65

10R 10R

1/4W 1% metal film

R

66

10k

1/4W 1% metal film

R

67-68

100R

1/4W 1% metal film

R

69

1k2

1/4W 1% metal film

R

70-71

2k2

1/4W 1% metal film

R

72-73 72- 73

10R

1/4W 1% metal film

R

74

10 k

1/4W 1% metal film

R

75-76

100R

1/4W 1% metal film

R

77

1k 2

1/4W 1% metal film

R

78-79

2k2

1/4W 1% metal film

R

81-81 81- 81

10R

1/4W 1% metal film

R

82

10K

1/4W 1% metal film

R

83-84 83-8 4

100R 100R

1/4W 1% metal film

R

85

1k2

1/4W 1% metal film

R

86-87

2k2

1/4W 1% metal film

R

88-89

I 0R

1/4W 1% metal film

R

90

10K 10K

1/4W 1% metal film

R

91-92

100R 100 R

1/4W 1% metal film

R

93

1k2

1/4W 1% metal film

R

94-95

2k2

1/4W 1% metal film

R

96-97 96- 97

10R

1/4W 1% metal film

R

98

10K

1/4W 1% metal film

R

99-100

100R

1/4W 1% metal film

R

101

1k2

1/4W 1% metal film

R

102-103

2k2

1/4W 1% metal film

R

104-105 104- 105

10R 10R

1/4W 1% metal film

R

106 10 6

10K

1/4W 1% metal film

R

107-108 107-1 08

100R 100R

1/4W 1% metal film

R

109

1k 2

1/4W 1% metal film

PARTS LIST


Value

Description

R

110-111

2k2

1/4W 1% metal film

R

112-113

10R

1/4W 1% metal film

R

114

10K

1/4W 1% metal film

R

115-116

100R

1/4W 1% metal film

R

117

1k2

1/4W 1% metal film

R

118-119

2k2

1/4W 1% metal film

R

120-121

10R

1/4W 1% metal film

R

122

10K

1/4W 1% metal film

R

123-124

120R

1/4W 1% metal film

R

125-126

1k5

1/4W 1% metal film

R

127-128

2k2

1/4W 1% metal film

C

1-2

10µF

25V Electrolyt ic NP 2.5mm spacing

C

3-4

220pF

1 % Polystyrene axial 160V

C

5

6.8 pF

63V Ceramic 5mm spacing

C

6-7

10µF

25V Electrolyt ic NP 2.5mm spacing

C

8-9

220pF


C

10

6.8 pF


C

11-12

10pF 10pF


C

13-36

150pF


C

37-56

0.1µ F


C

57-58

10µF

25V Electrolytic 2.5mm spacing

C

59-60 5 9-60

0.1µ F


C

61-62

220µF

25V Electrolytic 5mm spacing

D

1-2

1N4007 1N40 07

Silicon diode

P

1-2

10k

Bourns 3296P Trimpot

Q

1

LM317

Positive Adjustable Voltage Regulator

Q

2

LM337

Negative Adjustable Voltage Regulator

PARTS LIST


Value

Description

U

1-15

NE5532 NE5532

Dual Low Noise Operational Amplifier

J

1-3

Jumper

2.54mm Molex

CON CON

1

64 way Edge Conn.

DIN41612 90° male (AB row)


STEREO AUDIO DISTRIBUTION AMPLIFIER MODULE E-234 JUMPER CONFIGURATIONS CONFIGURATIONS

Stereo Audio Distribution Amplifier – Type E234

STEREO AUDIO DISTRIBUTION AMPLIFIER TYPE E234 CIRCUIT DIAGRAM


STEREO AUDIO DISTRIBUTION AMPLIFIER MODULE E-234 CIRCUIT DIAGRAM


P.O.Box 3073 Pinegowrie 2123 Gauteng South Africa Tel: +27 11 838 0620 Fax: +27 11 838 0625 e-mail: [email protected]

www.soundfusion.co.za


SPECIFICATIONS Input impedance

> 10k

Output impedance

> 20 Ohms

Gain range (pot)

-12dB to +12dB

C.M.R.R. (ref + 6 dBu input)

Signal to Noise (ref + 6 dBu input)

100 Hz

> 60dB

1 kHz

> 62dB

10kHz

> 62dB

20kHz

> 62dB

Unweighted

< -90dB

(30 kHz BW) “A” weighted

< -100dB

Frequency Response Maximum Output (unity gain/ <0.1%THD) Amplifier driving 500 meters screened cable terminated in 10kOhms.

10 Hz to 20 kHz

< -0.05dB

20 Hz - 20 KHz

> +22dBu

Amplifier driving 500 metres screened cable terminated in 600 Ohms

20 Hz -20 kHz

> +18 dBu

20 Hz - 50 KHz

< 0.004 %

Total Harmonic Distortion. Amplifier driving 500 meters screened cable terminated in 10 kOhms and 600 Ohm load at+l8dBu (Unity gain)

20 Hz -20 kHz

< 0.006 %

Intermodulation Distortion 600 Hz and 7 kHz

20 Hz - 50 kl-fz

< 0.003 %

Cross talk

50 kHz

> -75 dBu

Total Harmonic Distortion 10 k Ohms and 600 Ohm load at +6 dBu (Unity gain)

10Hz

> - 130dBu

Audio Distribution Circuit

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