Downloads: Sound of Shadows v3 Manual SoS v3 Kit Manual
MSRP: US$149
Module width: 8hp
Supply Voltage ±12VDC
Supply Current (max draw @ ±12V) +12V: 51mA -12V: -21mA
Supply Current (max draw @ ±12V & +5V) +12V: 19mA -12V: -15mA -5V: -21mA
Max. Input Voltage (@ ±12V) 10Vp-p
Max. Output Voltage 6Vp-p
Input & Ouput (I/O) coupling Direct*
Output Impedance 1kΩ
Control Voltage (CV) inputs ±Vsupply
CV input coupling Direct
CV input impedance 100kΩ
Mounting Depth 35mm
Delay Length Min: ~31.3ms Max: ~342ms

SoS v3 on Modulargrid.

What is the Sound of Shadows?

The Sound of Shadows (SoS) is a voltage-controlled (VC) digital delay module based around the PT2399 echo IC from Princeton Technology – which was, by the way, originally designed for Karaoke equipment.

As with all f(h) products, the SoS was engineered towards maximizing functionality while keeping cost as low as possible. If some aspects of the unit seem awkward, it is most likely due to this. The goal is to make unique, useful, enjoyable, and affordable instruments, not just hoover out your bank account.

And remember: every instrument has its quirks and unexpected aspects, so RTFM! All the way through! Specific quirks are mentioned in the description of the particular feature they apply to, so please read this through before emailing!

*Details, samples, updates, and discussion can be found on the SoS thread on*

Difference in v3 from v2:

  • Removed VCA
  • Chainable rear header
    • Delay out
    • Insert in (Similar to using the insert jack but bypasses the Insert pot. Goes through feedback gain cell before entering delay.)
    • Delay in (Equivalent to Using the Input jack, no attenuation.)
  • Added +5V source selection jumper (board/bus) and changed to full 16-pin power header.

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