Noise Generator on ER-PROTO-01

Features

• Eurorack 6HP, 3U module
• Noise Generator
  • Based on Moritz Klein's Designing a white, pink & blue noise generator from scratch design
  • White, Pink, Blue noise outputs
  • Outputs are all buffered
• Built on ER-PROTO-01 card
• 10 pin Eurorack power connector

Noise Generator

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

• Noise Generator

• White/Pink/Blue noise

• High Pass Filter (Blue Noise)

• Low Pass Filter (Pink Noise)

Build

White Noise Generator

• Voltage Gain = 148
• Switched from TL074 to TL084

• 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

• Schematic with offset

White Noise Scopecaps

• White Noise Scope capture
• 2 mS / div

• FFT, 25HKz range

Blue Noise Generator

Blue Noise Screencaps

• FFT 1mS scope setting

Pink Noise Generator

Pink Noise Scopecaps

Pink Noise LTSpice

Jacks

Connectors

J1 - White Output

• +/- 7.5V swing

Eurorack Power

Build Details

• Three card set
  • ER-PROTO-01 Front Panel card
  • ER-PROTO-01 Controls card
  • ER-PROTO-01 Daughtercard

On Controls Card

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

On Daughtercard

• Transistor Noise Source wiring

• Opamp wiring

References

schmitzbits White Noise Source