ER-VCF-02

Features

• This is a diode ladder VCF - original design by Moritz Klein, with a couple of small adaptions made by T Killa
• There are two CV inputs
  • CV1 with an attenuator to control the amount
  • CV2 with an attenuverter so it's possible to invert the signal as well as controlling the amount of modulation
• The filter is a low-pass filter only
• 3U tall
• 6 HP (30mm) wide
• Uses ER-PROTO-02 controls cards

Credits

• Tommy Killander Design

Pots/Connectors

Front Panel Pots

• POT RV1 - CV1 Attenuator adjustment
• POT RV2 - CV2 Attenuaverter adjustment
• POT RV3 - Not used
• POT RV4 - Not used
• POT RV5 - Resonance adjustment
• POT RV6 - Cutoff Frequency adjustment

Front Panel External Connectors

• J3 - Audio In
• J4 - CV Amount
• J5 - Attenuaverter input
• J6 - Audio Out

J3 - Audio In

• 3.5mm mono connector
• Tip - signal

J4 - CV Amount

• 3.5mm mono connector
• Tip - signal

J5 - Attenuaverter input

• 3.5mm mono connector
• Tip - signal

J6 - Audio Out

• 3.5mm mono connector
• Tip - signal

Front Panel Controls to Analog Card Connectors

J5 - Pot connector

J10 - Jack connector

Analog Card Connectors

J1 - Eurorack Power

J2 - POT (from Controls card)

J3 - Jacks (to/from Controls card)

Schematics

[1]

Issues

Rev 1

• Working

Videos

• Design base on Low Pass only version of Moritz Klein's design

• Not Voltage controlled, but interesting
  • Chapter 11.7 of Op Amps Textbook

Assembly Sheet

• Three card set
  • Front Panel
  • ER-PROTO-02 Controls card
    • RV1, RV2, RV5, RV6 (No RV3, RV4)
    • J3-J5
  • Analog card

• ER-VCF-02 Rev 1 Interactive BOM
• ER-VCF-02 Rev 1 Assembly Sheet