IC Audio Power Amplifiers: Circuit Design For Audio Quality and EMC
Audio Distribution Circuit
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Transcript of 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. R eg . No . 19 94 00 95 87 0
TECHNICAL MANUAL
STEREO
AUDIO DISTRIBUTION AMPLIFIER
MODULE E-234
Stereo Distribution 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 distribution amplifier, but can be configured by means of jumpers to provide the following options: a) One stereo input, six stereo outputs. b) One stereo input, five stereo outputs, 2 mono outputs. c) One stereo input, twelve mono outputs. d) 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 VDC at pins 2 and 3, which is fed to the adjustable voltage regulators Ql Q2. There is pre-regukition decoupling with C55, C56. 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
STEREO AUDIO DISTRIBUTION AMPLIFIER
MODULE E-234
COMPONENT LAYOUT
Stereo Audio Distribution Amplifier Module E-234Stereo Audio Distribution Amplifier Module E-234 Component Layout
+ +
+
+
C16
R39
R41R42
R36R35
R40
R37
R38
C15
C20
R55
R57
R58
R52
R51
R56
R53
R54
C19
C24
R71
R73
R74
R68
R67
R72
R69
R70
C23
C28
R87
R89R90
R84
R83
R88
R85
R86
C27
C32
R103
R105
R106
R100
R99
R104
R101
R102
C31
C36
R119
R121
R122
R116
R115
R120
R117
R118
C35
J3
C34
R111
R113
R114
R108
R107
R112
R109
R110
C33
C30
R95
R97R98
R92R91
R96
R93
R94
C29
C26
R79
R81R82
R76R75
R80
R77
R78
C25
C22
R63
R65R66
R60R59
R64
R61
R62
C21
C18
R47
R49R50
R44R43
R48
R45
R46
C17
C46 C48 C50 C52 C54
U15U13U11U9U7
C14
R31
R33R34
R28R27
R32
R29
R30
C13
C44
U5
C43
U4 U6 U8 U10 U12 U14C53C51C49C47C45C42
C62 C61 C60C59
C1 C2 C6 C7
J2
C12
R26R23
R24
R1R4
R2R3
R13R12
R11R14
C57
C58C3
C5
R7
R9
R6R5
R8
R10
C4
C8
C10
R17
R19
R16
R15
R18
R20
C9R21
R22R25
C11
C41U3U2U1
C40C39C38C37
P2J1P1LD2LD1
R128R127
R126R124
C55D1D2Q1Q2C56
R125
R123
ADA234
SOUNDFUSION
0V -V +V 1L 1R 2L 2R 3L 3R 4L 4R 5L 5R 6L 6R IN-L IN-R
Stereo Audio Distribution Amplifier Module E-234Stereo 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 l0k 1/4 W 1 % metal film
R 8-9 lk 1/4 W 1 % metal film
R 10 120R 1/4 W 1 % metal film
R 11 20K 1/4 W 1 % metal film
R 12-17 l0k 1/4 W 1 % metal film
R 18-19 lk 1/4 W 1 % metal film
R 20 120R 1/4 W 1 % metal film
R 21-24 l0k 1/4 W 1 % metal film
R 25-26 5k1 1/4 W 1 % metal film
R 27-28 100R 1/4 W 1 % metal film
R 29 lk2 1/4 W 1 % metal film
R 30-31 2k2 1/4 W 1 % metal film
R 32-33 10R 1/4 W 1 % metal film
R 34 10K 1/4 W 1 % metal film
R 35-36 100R 1/4 W 1 % metal film
R 37 lk2 1/4 W 1 % metal film
R 38-39 2k2 1/4 W 1 % metal film
R 40-41 10R 1/4 W 1 % metal film
R 42 l0k 1/4 W 1 % metal film
R 43-44 100R 1/4 W 1 % metal film
R 45 1k2 1/4 W 1 % metal film
R 46-47 2k2 1/4 W 1 % metal film
R 48-49 10R 1/4 W 1 % metal film
R 50 10K 1/4 W 1 % metal film
R 51-52 100R 1/4 W 1 % metal film
R 53 1k2 1/4 W 1 % metal film
R 54-55 2k2 1/4 W 1 % metal film
R 56-57 10R 1/4 W 1 % metal film
R 58 10K 1/4 W 1 % metal film
R 59-60 100R 1/4 W 1 % metal film
PARTS LIST
Audio Distribution Amplifier Module E-234Reference Value Description
R 61 1k2 1 /4W 1% meta l f i lm
R 62-63 2k2 1 /4W 1% meta l f i lm
R 64-65 10R 1 /4W 1% meta l f i lm
R 66 10k 1 /4W 1% meta l f i lm
R 67-68 100R 1 /4W 1% meta l f i lm
R 69 1k2 1 /4W 1% meta l f i lm
R 70-71 2k2 1 /4W 1% meta l f i lm
R 72-73 10R 1 /4W 1% meta l f i lm
R 74 10k 1 /4W 1% meta l f i lm
R 75-76 100R 1 /4W 1% meta l f i lm
R 77 1k2 1 /4W 1% meta l f i lm
R 78-79 2k2 1 /4W 1% meta l f i lm
R 81-81 10R 1 /4W 1% meta l f i lm
R 82 10K 1 /4W 1% meta l f i lm
R 83-84 100R 1 /4W 1% meta l f i lm
R 85 1k2 1 /4W 1% meta l f i lm
R 86-87 2k2 1 /4W 1% meta l f i lm
R 88-89 I 0R 1 /4W 1% meta l f i lm
R 90 10K 1 /4W 1% meta l f i lm
R 91-92 100R 1 /4W 1% meta l f i lm
R 93 1k2 1 /4W 1% meta l f i lm
R 94-95 2k2 1 /4W 1% meta l f i lm
R 96-97 10R 1 /4W 1% meta l f i lm
R 98 10K 1 /4W 1% meta l f i lm
R 99-100 100R 1 /4W 1% meta l f i lm
R 101 1k2 1 /4W 1% meta l f i lm
R 102-103 2k2 1 /4W 1% meta l f i lm
R 104-105 10R 1 /4W 1% meta l f i lm
R 106 10K 1 /4W 1% meta l f i lm
R 107-108 100R 1 /4W 1% meta l f i lm
R 109 1k2 1 /4W 1% meta l f i lm
PARTS LIST
Audio Distribution Amplifier Module E-234Reference 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 Electrolytic NP 2.5mm spacing
C 3-4 220pF 1 % Polystyrene axial 160V
C 5 6.8pF 63V Ceramic 5mm spacing
C 6-7 10µF 25V Electrolytic NP 2.5mm spacing
C 8-9 220pF 1 % Polystyrene axial 160V
C 10 6.8pF 63V Ceramic 5mm spacing
C 11-12 10pF 63V Ceramic 5mm spacing
C 13-36 150pF 1 % Polystyrene axial 160V
C 37-56 0.1µF 63V Ceramic 5mm spacing
C 57-58 10µF 25V Electrolytic 2.5mm spacing
C 59-60 0.1µF 63V Ceramic 5mm spacing
C 61-62 220µF 25V Electrolytic 5mm spacing
D 1-2 1N4007 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
Audio Distribution Amplifier Module E-234 Reference Value Description
U 1-15 NE5532 Dual Low Noise Operational Amplifier
J 1-3 Jumper 2.54mm Molex
CON 1 64 way Edge Conn. DIN41612 90° male (AB row)
Stereo Audio Distribution Amplifier – Module E-234
STEREO AUDIO DISTRIBUTION AMPLIFIER
MODULE E-234
JUMPER CONFIGURATIONS
Stereo Audio Distribution Amplifier – Type E234
STEREO AUDIO DISTRIBUTION AMPLIFIER
TYPE E234
CIRCUIT DIAGRAM
Stereo Audio Distribution Amplifier – Module E-234
STEREO AUDIO DISTRIBUTION AMPLIFIER
MODULE E-234
CIRCUIT DIAGRAM
Stereo Audio Distribution Amplifier – Module E-234Stereo Audio Distribution Amplifier – Module E-234
P.O.Box 3073Pinegowrie
2123 Gauteng
South Africa
Tel: +27 11 838 0620 Fax: +27 11 838 0625
e-mail: [email protected] www.soundfusion.co.za
Stereo Audio Distribution Amplifier – Module E-234 SPECIFICATIONS
Input impedance > 10k
Output impedance > 20 Ohms
Gain range (pot) -12dB to +12dB
C.M.R.R. (ref + 6 dBu input) 100 Hz > 60dB
1 kHz > 62dB
10kHz > 62dB
20kHz > 62dB
Signal to Noise (ref + 6 dBu input) Unweighted < -90dB
(30 kHz BW)
“A” weighted < -100dB
Frequency Response 10 Hz to 20 kHz < -0.05dB Maximum Output (unity gain/ <0.1%THD) Amplifier driving 500 meters screened cable terminated in 10kOhms. 20 Hz - 20 KHz > +22dBu Amplifier driving 500 metres screened cable terminated in 600 Ohms 20 Hz -20 kHz > +18 dBu Total Harmonic Distortion 10 k Ohms and 600 Ohm load at +6 dBu (Unity gain) 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 10Hz > - 130dBu 50 kHz > -75 dBu