Back in the 90’s, computer audio devices were really limited. If you were relatively rich, you could afford a $150 Sound Blaster, or maybe a $75 Adlib. If not, you were limited to the very humble PC speaker. It turns out, however, there was one other option that didn’t get a lot of visibility.

The Covox Speech Thing (and a similar device called the Disney Sound Source) was an external audio device attached to the printer port and could output digitally generated sound. The device was a criminally simple 8-bit DAC created with a resistor ladder, an analogue output plug, and ran off simple digital signals from the printer port of the PC. How simple was it? So simple you can easily make it yourself.

Necroware does a great job covering the device, how to make your own, and gives you a full tour of the device as well as 90’s software you can use with it. Most notably, Tracker software which gave me tons of fond memories.

Update 02/2024:

Serdashop has the Covox compatible CVX4 Vogons Tuning Edition for €20. Now on it’s 4th and final version – CVX4 uses very high precision 0.1% all same value resistors, and a reverse engineered schematic (based on a real original covox). Other DIY clones use 1% or 5% resistors. Probably one of the best versions out there.

Links:

• https://hackaday.com/2014/09/29/the-lpt-dac/
• https://www.serdashop.com/CVX4