(kicad_sch
  (version 20231120)
  (generator "eeschema")
  (generator_version "8.0")
  (uuid "cams1-amp-hf-0003")
  (paper "A3")
  (title_block
    (title "CAMS-1 — HF Power Amp (LM3886TF) G=21 + -6dB pad")
    (date "2026-08-28")
    (rev "A")
    (comment 1 "Same as MID amp plus resistive pad Rpad1/Rpad2 before Cin")
    (comment 2 "Tune pad in QC for flat on-axis FR")
  )

  (lib_symbols
    (symbol "Device:R"
      (property "Reference" "R" (at 2.032 0 90) (effects (font (size 1.27 1.27))))
      (property "Value" "R" (at 0 0 90) (effects (font (size 1.27 1.27))))
      (symbol "R_0_1" (rectangle (start -1.016 -2.54) (end 1.016 2.54) (stroke (width 0.254) (type default)) (fill (type none))))
      (symbol "R_1_1"
        (pin passive line (at 0 3.81 270) (length 1.27) (name "~" (effects (font (size 1.27 1.27)))) (number "1" (effects (font (size 1.27 1.27)))))
        (pin passive line (at 0 -3.81 90) (length 1.27) (name "~" (effects (font (size 1.27 1.27)))) (number "2" (effects (font (size 1.27 1.27))))))
    )
    (symbol "Device:C"
      (property "Reference" "C" (at 0.635 2.54 0) (effects (font (size 1.27 1.27))))
      (property "Value" "C" (at 0.635 -2.54 0) (effects (font (size 1.27 1.27))))
      (symbol "C_0_1"
        (polyline (pts (xy -2.032 -0.762) (xy 2.032 -0.762)) (stroke (width 0.508) (type default)) (fill (type none)))
        (polyline (pts (xy -2.032 0.762) (xy 2.032 0.762)) (stroke (width 0.508) (type default)) (fill (type none))))
      (symbol "C_1_1"
        (pin passive line (at 0 3.81 270) (length 2.794) (name "~" (effects (font (size 1.27 1.27)))) (number "1" (effects (font (size 1.27 1.27)))))
        (pin passive line (at 0 -3.81 90) (length 2.794) (name "~" (effects (font (size 1.27 1.27)))) (number "2" (effects (font (size 1.27 1.27))))))
    )
    (symbol "Amplifier_Audio:LM3886"
      (property "Reference" "U" (at 0 12.7 0) (effects (font (size 1.27 1.27))))
      (property "Value" "LM3886TF" (at 0 -12.7 0) (effects (font (size 1.27 1.27))))
      (symbol "LM3886_0_1" (rectangle (start -10.16 10.16) (end 10.16 -10.16) (stroke (width 0.254) (type default)) (fill (type background))))
      (symbol "LM3886_1_1"
        (pin input line (at -12.7 5.08 0) (length 2.54) (name "+" (effects (font (size 1.27 1.27)))) (number "8" (effects (font (size 1.27 1.27)))))
        (pin input line (at -12.7 -2.54 0) (length 2.54) (name "-" (effects (font (size 1.27 1.27)))) (number "9" (effects (font (size 1.27 1.27)))))
        (pin output line (at 12.7 2.54 180) (length 2.54) (name "OUT" (effects (font (size 1.27 1.27)))) (number "3" (effects (font (size 1.27 1.27)))))
        (pin power_in line (at 0 12.7 270) (length 2.54) (name "V+" (effects (font (size 1.27 1.27)))) (number "1" (effects (font (size 1.27 1.27)))))
        (pin power_in line (at 0 -12.7 90) (length 2.54) (name "V-" (effects (font (size 1.27 1.27)))) (number "4" (effects (font (size 1.27 1.27)))))
        (pin input line (at -12.7 -7.62 0) (length 2.54) (name "MUTE" (effects (font (size 1.27 1.27)))) (number "6" (effects (font (size 1.27 1.27)))))
        (pin passive line (at 12.7 -5.08 180) (length 2.54) (name "GND" (effects (font (size 1.27 1.27)))) (number "7" (effects (font (size 1.27 1.27))))))
    )
    (symbol "power:GND" (power)
      (property "Reference" "#PWR" (at 0 -6.35 0) (effects (font (size 1.27 1.27)) hide))
      (property "Value" "GND" (at 0 -3.81 0) (effects (font (size 1.27 1.27))))
      (symbol "GND_0_1" (polyline (pts (xy 0 0) (xy 0 -1.27) (xy 1.27 -1.27) (xy 0 -2.54) (xy -1.27 -1.27) (xy 0 -1.27)) (stroke (width 0) (type default)) (fill (type none))))
      (symbol "GND_1_1" (pin power_in line (at 0 0 270) (length 0) hide (name "~" (effects (font (size 1.27 1.27)))) (number "1" (effects (font (size 1.27 1.27))))))
    )
  )

  (hierarchical_label "IN" (shape input) (at 20.32 63.5 180)
    (effects (font (size 1.27 1.27)) (justify right)) (uuid "hl_in"))
  (hierarchical_label "SPK_HF" (shape output) (at 220.98 63.5 0)
    (effects (font (size 1.27 1.27)) (justify left)) (uuid "hl_out"))
  (hierarchical_label "+25V" (shape input) (at 139.7 35.56 90)
    (effects (font (size 1.27 1.27)) (justify left)) (uuid "hl_p"))
  (hierarchical_label "-25V" (shape input) (at 139.7 96.52 270)
    (effects (font (size 1.27 1.27)) (justify left)) (uuid "hl_n"))
  (hierarchical_label "GND" (shape input) (at 50.8 110.0 270)
    (effects (font (size 1.27 1.27)) (justify left)) (uuid "hl_g"))

  (text "HF PAD (~-6dB): Rpad1 series 5.6k then Rpad2 5.6k to GND — same topology as MID after pad"
    (exclude_from_sim no) (at 20.32 25.4 0)
    (effects (font (size 1.27 1.27)) (justify left bottom)) (uuid "t0"))
  (text "Copy all MID amp passives (Cin..Lout) with _H suffix — see COMPONENTS_COMPLETE.csv"
    (exclude_from_sim no) (at 20.32 27.94 0)
    (effects (font (size 1.27 1.27)) (justify left bottom)) (uuid "t1"))

  (symbol (lib_id "Device:R") (at 35.56 63.5 90) (unit 1)
    (uuid "rp1") (property "Reference" "Rpad1" (at 35.56 58.42 90) (effects (font (size 1.27 1.27))))
    (property "Value" "5.6k" (at 35.56 68.58 90) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "rp1a")) (pin "2" (uuid "rp1b")))
  (symbol (lib_id "Device:R") (at 50.8 80.01 0) (unit 1)
    (uuid "rp2") (property "Reference" "Rpad2" (at 56 78.74 0) (effects (font (size 1.27 1.27))))
    (property "Value" "5.6k" (at 56 81.28 0) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "rp2a")) (pin "2" (uuid "rp2b")))
  (symbol (lib_id "power:GND") (at 50.8 83.82 0) (unit 1)
    (uuid "gp") (property "Reference" "#PWRH0" (at 50.8 83.82 0) (effects (font (size 1.27 1.27)) hide))
    (property "Value" "GND" (at 50.8 87.63 0) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "gpp")))
  (symbol (lib_id "Device:C") (at 66.04 63.5 90) (unit 1)
    (uuid "cin") (property "Reference" "Cin_H" (at 66.04 58.42 90) (effects (font (size 1.27 1.27))))
    (property "Value" "1uF" (at 66.04 68.58 90) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "cina")) (pin "2" (uuid "cinb")))
  (symbol (lib_id "Device:R") (at 86.36 63.5 90) (unit 1)
    (uuid "rin") (property "Reference" "Rin_H" (at 86.36 58.42 90) (effects (font (size 1.27 1.27))))
    (property "Value" "1k" (at 86.36 68.58 90) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "rina")) (pin "2" (uuid "rinb")))
  (symbol (lib_id "Amplifier_Audio:LM3886") (at 139.7 66.04 0) (unit 1)
    (uuid "u2") (property "Reference" "U2" (at 139.7 50.8 0) (effects (font (size 1.27 1.27))))
    (property "Value" "LM3886TF" (at 139.7 81.28 0) (effects (font (size 1.27 1.27))))
    (pin "8" (uuid "u2a")) (pin "9" (uuid "u2b")) (pin "3" (uuid "u2c"))
    (pin "1" (uuid "u2d")) (pin "4" (uuid "u2e")) (pin "6" (uuid "u2f")) (pin "7" (uuid "u2g")))
  (symbol (lib_id "Device:R") (at 114.3 88.9 90) (unit 1)
    (uuid "rf") (property "Reference" "Rf_H" (at 114.3 83.82 90) (effects (font (size 1.27 1.27))))
    (property "Value" "20k" (at 114.3 93.98 90) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "rfa")) (pin "2" (uuid "rfb")))
  (symbol (lib_id "Device:R") (at 114.3 104.14 0) (unit 1)
    (uuid "ri") (property "Reference" "Ri_H" (at 119 102.87 0) (effects (font (size 1.27 1.27))))
    (property "Value" "1k" (at 119 105.41 0) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "ria")) (pin "2" (uuid "rib")))
  (symbol (lib_id "Device:C") (at 114.3 111.76 0) (unit 1)
    (uuid "ci") (property "Reference" "Ci_H" (at 119 110.49 0) (effects (font (size 1.27 1.27))))
    (property "Value" "220uF" (at 119 113.03 0) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "cia")) (pin "2" (uuid "cib")))
  (symbol (lib_id "power:GND") (at 114.3 115.57 0) (unit 1)
    (uuid "g2") (property "Reference" "#PWRH2" (at 114.3 115.57 0) (effects (font (size 1.27 1.27)) hide))
    (property "Value" "GND" (at 114.3 119.38 0) (effects (font (size 1.27 1.27))))
    (pin "1" (uuid "g2p")))

  (label "PAD_NODE" (at 50.8 62.23 0) (effects (font (size 1.27 1.27)) (justify left bottom)) (uuid "lpad"))
  (label "HF_N_PLUS" (at 96.52 62.23 0) (effects (font (size 1.27 1.27)) (justify left bottom)) (uuid "lp"))
  (label "HF_OUT" (at 165.1 62.23 0) (effects (font (size 1.27 1.27)) (justify left bottom)) (uuid "lo"))

  (text "Also fit: Cf_H 20pF, Zobel 10R+0.1uF, Lout 0.68uH||10R, mute 100k+10uF, 100nF+1000uF rails — mirror MID sheet"
    (exclude_from_sim no) (at 20.32 130.0 0)
    (effects (font (size 1.27 1.27)) (justify left bottom)) (uuid "t2"))

  (sheet_instances (path "/" (page "HF")))
)