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Bill of Materials

Main board BOM

# Designator Value Quantity Supplier Part Number Comment
Capacitors, film
  C25*, C50 0.1uF/63V 2 Mouser MKS2.1/63/5 * - optional, for 3124 mod
  C52, C8*, C9* 0.47uF/63V 3 Mouser MKS2C034701C00JO00 * - optional, for servo circuit
Capacitors, ceramic
  C1 220pF 1 Mouser C324C221J1G5TA  
  C18*, C19*, C23**, C24**, Cp2, Cp6, Cp11, Cp12** 0.1uF 6 Mouser K104K15X7RF53L2

* - optional, for monolithic op-amp

** - optional, for servo circuit

  C20, C21, C22 470pF 3 Mouser 1C10C0G471J050B  
  C53 0.01uF 1 Mouser FG18C0G1H103JNT06  
  C6 120pF 1 Mouser C315C121J1G5TA  
  C7* 100pF 1 Mouser C324C101J1G5TA * - optional, for monolithic op-amp
Capacitors, electrolytic (Low ESR recommended)
  C101 18uF/50V 1 Mouser UPW1H180MDD  
  C102 10uF/50V 1 Mouser UPW1H100MDD  
  C3, C26* 470uF/35V 2 Mouser UEP1V471MHD

Non polar

* - optional, for 3124 mod

  C4, C5, Cp3, Cp4, Cp7, Cp8* 22uF/35V 6 Mouser UPW1V220MDD * - optional, for servo circuit
  Cp1, Cp5 1000uF/50V 2 Mouser UPW1H102MHD1CV Low profile, <30mm
  Cp9, Cp10 100uF/63V 2 Mouser UPW1J101MPD6  
Resistors (1% recommended, except where noted)
  R1 9.76K 1 Mouser 271-9.76K-RC  
  R100, R101 750 2 Mouser 271-750-RC  
  R102 160 1 Mouser 271-160-RC  
  R103 5.1K 2 Mouser 271-5.1K-RC  
  R11, R12, R13, R14, R108 820 5 Mouser 271-820-RC  
  R3 200 1 Mouser 271-200-RC  
  R36, R37 6.81K 2 Mouser RC55LF-D-6K81-B-B


  R4, R104 20K 2 Mouser 271-20K-RC  
  R5*, R57, Rp8 100K 3 Mouser 271-100K-RC * - optional, for servo circuit
  R51 2M 1 Mouser 271-2.0M-RC  
  R52 3.6M 1 Mouser MFR50SFTE52-3M6  
  R53 4.7M 1 Mouser MFR50SFTE52-4M7  
  R54 680 1 Mouser 271-680-RC  
  R55 1.2K 1 Mouser 271-1.2K-RC  
  R6*, R7* 1M 2 Mouser 271-1.0M-RC * - optional, for servo circuit
  R8* 47 1 Mouser 271-47-RC * - optional, for 3124 mod
  R9*, R56 100 2 Mouser 271-100-RC * - optional, for monolithic op-amp
  RG1 15.8K 1 Mouser 271-15.8K-RC  
  RG10 205 1 Mouser 271-205-RC  
  RG11 86.6 1 Mouser 271-86.6-RC  
  RG2 9.09K 1 Mouser 271-9.09K-RC  
  RG3 5.49K 1 Mouser 271-5.49K-RC  
  RG4 3.57K 1 Mouser 271-3.57K-RC  
  RG5 2.32K 1 Mouser 271-2.32K-RC  
  RG6 1.5K 1 Mouser 271-1.5K-RC  
  RG7 976 1 Mouser 271-976-RC  
  RG8 619 1 Mouser 271-619-RC  
  RG9 374 1 Mouser 271-374-RC  
  R15, Rp2, Rp6 330 3 Mouser 271-330-RC  
  Rp3, Rp5 4.42K 2 Mouser 271-4.42K-RC  
  Rp9 10K 1 Mouser 271-10K-RC  
  Ropt* 22K 1 Mouser 271-22K-RC * - optional, 22K to 150K. Sets HF responce
  TRIM 600R T-Pad 1 CAPI Bourns-51-t-pad  
  D101 1N749A 1 Mouser


  D11, D12, D13, D14, D102, Dp1, Dp2, Dp3, Dp4, Dp5, Dp6 1N4007G 11 Mouser 1N4007G  
  D50, D103 1N914 2 Mouser 1N914  
  PWR ON Power On LED 1 Mouser W23GD Or any other 2mm green LED
  Q3 LM317LZ 1 Mouser LM317LZ  
  Q100 BC550C 1 Mouser BC550C  
  Q50 2N4393 1 Mouser 2N4393 or
  Q51 2N4126 1 Mouser 2N4126  
  Qp1 MPSA06 1 Mouser MPSA06  
  Qp2 MPSA56 1 Mouser MPSA56  
  U1 2520 1   2520 Any DOA of your choice or see separate BOM
  U2_* AD797 1 Mouser AD797ANZ * - optional, for monolithic op-amp
  U3* LT1013DIP 1 Mouser LT1013DIP * - optional, for servo circuit
  Up1 LM317T 1 Mouser LM317T  
  Up2 LM337T 1 Mouser LM337T  
  Up3 LM78L12 1 Mouser LM78L12ACZ/NOPB  
  Up4* LM79L12 1 Mouser LM79L12ACZ/NOPB * - optional, for servo circuit
Switches and relays
  K1, K2, K3, K4, K5 Relay, DPDT 5 Mouser TQ2-24V

Alternative variant:


(adjust R11-R14, R108 as noted!)

  PHANTOM SPDT 1 Mouser 108-1MS1T1B1M1QE-EVX  
  3to1, IMPEDANCE, PAD, PHASE DPDT 4 Mouser TL2201EEZA  
  GAIN_SW   1 Mouser 56DP30-01-1-AJN Stopped to 12 pos
  TO-220 heatsink, vertical   2 Mouser 637-10ABPE  
  Line input XLR, Female 1 Mouser NC3FD-LX-B Or any other Neutrik Series D/DL/DLX female XLR
  Line output XLR, Male 1 Mouser NC3MD-LX-B Or any other Neutrik Series D/DL/DLX male XLR
  GAIN, IN, OUT, 48VDC, 48VDC|| Header 5 Mouser 22-23-2021  
    Wire housing 5 Mouser 22-01-2027  
  24VDC, 24VDC||, FROM_GAIN Header 3 Mouser 22-23-2031  
    Wire housing 3 Mouser 22-01-2037  
  _DI, _TRIM Header 2 Mouser 22-23-2041  
    Wire housing 2 Mouser 22-01-2047  
  DI, TRIM Header 2 Mouser 22-23-2051  
    Wire housing 2 Mouser 22-01-2057  
    Crinp pins 37 Mouser 08-50-0032  
  _FP, FP Header 2 Mouser 30310-6002HB  
    IDC socket 2 Mouser 164-9006-E  
  _DI_IN 1/4" JACK 1 Mouser NJ6FD-V  
  Op amp socket   6 Mouser 0322-0-15-15-34-27-10-0  
  T1 (Input) 2622 1 CAPI CA2622  
  T2 (Output) 2320 1 CAPI or Cinemag EA2503, 2503-Litz or

Choose CMOQ-2L or CMOQ-2R according to your preferences.

Knobs and switch caps
  For 1/8" shaft   1 Mouser MPKES60B1/8 Or any other knob with a single set screw
  For 1/4" shaft   1 Mouser MPKES60B1/4 Or any other knob
  Switch caps   4 Mouser 1RLGR  
  Flat cable   1 ft Mouser 3365/10-CUT-LENGTH  
  Standoff, unthreaded, nylon, M3 clearance x 3mm (front panel and output transformer spacers)   6 Mouser R30-6700394  
  Standoff, M3 x 10mm, F/F (for front controls bracket mounting)   4 Mouser R30-1001002  
  Standoff, M3 x 5mm, F/F (for module board mounting)   4 Mouser R30-1000502 May be replaced with threaded rivets

312 Module PCBs set   1 RackNeve 312PCB  
  312 Module front panel   1 RackNeve 312FP  

Discrete op-amp BOM

# Designator Value Quantity Supplier Part Number Comment
Capacitors, ceramic
  C10d, C11d 0.1uF 2 Mouser K104K15X7RF53L2


  C1d 1000pF 1 Mouser C315C102J5G5TA  
  C2d, C3d 47pF 2 Mouser C315C470J5G5TA  
  C4d 39pF 1 Mouser C315C390J5G5TA  
  C5d 10pF 1 Mouser C315C100J5G5TA  
Resistors (1% recommended, except where noted)
  R10d 806 1 Mouser 271-806-RC  
  R11d, R12d 5R6, 0.5W 2 Mouser MFR50SFTE52-5R6  
  R16d 47K 1 Mouser 271-47K-RC  
  R1d 150K 1 Mouser 271-150K-RC  
  R2d 360 1 Mouser 271-360-RC  
  R3d, R4d 20K 2 Mouser 271-20K-RC  
  R6d 3.3K 1 Mouser 271-3.3K-RC


  R7d 3.9K 1 Mouser 271-3.9K-RC  
  R8d, R14d, R15d 1K 3 Mouser 271-1K-RC  
  R9d, R13d 56 2 Mouser 271-56-RC  
  D1d, D2d, D3d, D4d 1N914 4 Mouser 1N914  
  Q1d, Q2d BC550C 2 Mouser BC550C Matched hfe pair
  Q3d, Q4d, Q5d BC850C 3 Mouser BC850CMTF SOT-23-3
  Q6d, Q9d BC860C 2 Mouser BC860BMTF SOT-23-3
  Q7d BD139 1 Mouser BD13916S  
  Q8d BD140 1 Mouser BD14016S  
  Op amp pin   6 Mouser 3103-2-00-21-00-00-08-0  
  Diode thermal clamps set C-201 1 RackNeve WC201 1 set or 2 pieces