- on Audio/Video/Photography
- Published in issue 2/2007 on page 0
Stereo Microphone Preamplifier
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CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor Members can exclusively download these files for free as part of their Membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service. Elektor recommends its business partner Eurocircuits as the company of choice for its own prototypes and volume production in selected cases.
The indication with connection point ‘C1’ should be moved one level down, i.e., from GND1 down to the same level as C9.
2. On the PCB component overlay, the labels of SMD resistors R29 and R32 have been transposed. Resistor 29 (2 k?) should be the top device in the row of resistors fitted to the right of S1 and S2. R2 (6k?8) should be directly below it.
R1,R12,R23,R34 = 470?
R2,R24 = 100?
R3,R33 = 4M?7
R4,R5,R25,R26 = 3k?3
R6,R11,R27,R32 = 6k?8
R7,R10,R28,R31,R45,R46 = 47k?
R8,R9,R29,R30 = 2k?
R13,R35 = 33?
R14,R22,R36,R44 = 220k?
R15,R37 = 2k?2
R16 à R19,R38-R41 = 22?
R20,R21,R42,R43 = 10k?
P1,P2 = potentiometer 10k? B Alps type RK09K11310KB (Farnell # 119-1725)
C1,C4,C6,C7,C8,C10,C13,C15,C16,C17,C19-C22 = 10µF 16 V tantalum, Vishay Sprague 595D106X9016B2T (Farnell # 392-8895)
C2,C3,C5,C9,C11,C12,C14,C18 = 470nF/25 V tantalum, Vishay Sprague 595D474X9025T2T (Farnell # 116-6814)
D1 = LED, 3mm, red
T1-T8 = BC856ALT1G, SMD, SOT-23, ON Semiconductor (Farnell # 114-7782)
T9,T10 = 2N7002, MOSFET, SMD, SOIC, Texas Instruments (Farnell # 102-1754)
IC1,IC2 = TL071CD, SMD, SOIC, Texas Instruments (Farnell # 958-9449)
K1,K2,K3 = 3.5mm jack socket with 3 contacts, Schurter R36310000 (Farnell # 149-933)
S1,S2 = SPST switch, angled pins, PCB mount, height = 12.7mm, C&K 7103MD9 AV2BE (Farnell # 957-5510)
BT1 = 9V battery with clip-on lead
K4 = 2-way PCB pinheader
Case with battery compartment, e.g. BC2, Farnell # 223-554
PCB, ref. 060237-I from ThePCBShop