Noise Generator on ER-PROTO-01

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Tindie-mediums.png

ER-PROTO-01 NOISE P1090103-FR-B-720px.jpg

Features[edit]

Noise Generator[edit]

  • Credit Moritz Klein's Designing a white, pink & blue noise generator from scratch design

  • Noise Generator

Moritz noise.PNG

  • White/Pink/Blue noise

Moritz WHITE PINK BLUE.PNG

  • High Pass Filter (Blue Noise)

Moritz HPF.PNG

  • Low Pass Filter (Pink Noise)

Moritz LPF.PNG

Build[edit]

White Noise Generator[edit]

  • Voltage Gain = 148
  • Switched from TL074 to TL084

ER-PROTO-01 NOISE WHITE Before.PNG

  • Output seems pretty quiet (~200 mV)
    • Issue is 2N3904 is much quieter than a BC548
    • Switched to BC548
  • Offset errors = about 500 mV
    • Gain = 148, 500mV = 3.5mV offset voltage
    • Add offset voltage trimmer
    • Circuit from here

OpAmp Offset Adj.PNG

  • Schematic with offset

ER-PROTO-01 NOISE WHITE.PNG

White Noise Scopecaps[edit]

  • White Noise Scope capture
  • 2 mS / div

White Noise Scope Cap-01.png

  • FFT, 25HKz range

FFT White Noise 25KHz.PNG

Blue Noise Generator[edit]

ER-PROTO-01 NOISE BLUE.PNG

Blue Noise Screencaps[edit]

  • FFT 1mS scope setting

FFT Blue J4 Noise 1mS.PNG

Pink Noise Generator[edit]

ER-PROTO-01 NOISE PINK.PNG

Pink Noise Scopecaps[edit]

Pink Noise Scope Cap.png

FFT Pink J4 Noise 1mS.PNG

Pink Noise LTSpice[edit]

ER-PROTO-01 NOISE Pink LTSpice.PNG

Jacks[edit]

ER-PROTO-01 NOISE J38.PNG

Connectors[edit]

J1 - White Output[edit]

  • +/- 7.5V swing

J3 - Pink Output[edit]

J4 - Blue Output[edit]

Eurorack Power[edit]

ER-PROTO-01 U1 PWR.PNG

Build Details[edit]

ER-PROTO-01 NOISE P1090115-720px.jpg

On Controls Card[edit]

ER-PROTO-01 NOISE P1080760-JacksRework-720px.jpg

  • Install J1, J3, J4
  • Wire J1-S to J3-S
  • Wire J3-S to J4-S

On Daughtercard[edit]

ER-PROTO-01 NOISE P1090110-720px.jpg

  • Transistor Noise Source wiring

ER-PROTO-01 NOISE P1090111-720px.jpg

  • Opamp wiring

ER-PROTO-01 NOISE P1090112-ANNOTATED-720PX.jpg