Sound quality

  • High quality precision filter capacitors
  • Stereo output terminals for dedicated high-fidelity output (available in all operating modes)
  • Sample playback fix for 8580 with configurable boost level and manual/automatic operating mode
  • Reduced audible noise due to individual voltage filtering and regulation for each SID
  • Configurable external audio input mute function for reduced noise
  • Replaces incorrect filter capacitors found in SX-64 and early C64 models

Voltage control

  • Generates safe and precise operating voltages for each SID
  • Protects SID input and output against over/under voltage and short circuit

Easy usage

  • Automatic SID model detection - any combination of 6581/8580 is supported
  • Manual on-the-fly switching between 6581 (old SID) and 8580 (new SID) - while the tunes/games/demos are playing!
  • Software selectable SID, allowing music player software to automatically select correct SID model
  • Stereo SID capable with second SID at either address $D420, $D5001 or $DE00
  • Also works with single SID if you just want to use old SID in new C64 or new SID in old C64

1) $D500 location is not possible on C128 models due to a slightly incompatible memory map


  • 4 detachable feature cables for easier installation and less clutter
  • Two lengths, you pick the length when ordering. Fits all variants of Commodore 64 and 128

Optional accessories:

  • The SIDFX adapter, our custom designed adapter that enables the SIDFX unit to fit into the ZIF sockets of a Reloaded MK1 motherboard while being mounted in a C64C chassis

Manufacturing of batch 2 is complete so we now have plenty of available stock!

Thanks to everyone who has shown interest by signing up on the wish list.

By exclusively accepting PayPal payments in our local currency DKK (Danish Kroner) we have been able to almost maintain the previous price level (only around €2 to €3 increase) even though this second batch size is much smaller and the component and manufacturing costs have generally increased.

Do you wish to purchase a SIDFX unit? Then please go to the wishlist and sign yourself up. You will receive a PayPal invoice from us within 24-48 hours. We aim to ship your order within 5 business days after receiving your payment.