Sontec’s mastering equalizers were among the first parametric EQs manufactured and are considered some of the most “musical” of all time. I.J. Research has released DIY kits for stereo and 8-channel versions of the Sontec, with a stepped, mastering version in the works.

Availability: No longer available.
Further reading:

• Sontec 1RU build thread
• Igor’s 8-channel Sontec eq!
• Promotional material for the Sontec EQ
• Universal Audio WebZine on the origins of the Sontec
• Front panels available from Purusha (DIY-Racked)