
I found myself in need of a very low-distortion 1,000 Hz sine wave
generator for an upcoming project.
A quick search on Ebay found several used pieces of test equipment that met or exceeded my requirements, but were priced at well over $1,000 USD.
I did also find some low-cost China sourced 1 kHz generator boards, but they had a distortion of 0.1% which was way above my 0.005% limit.
My current test gear includes a Keithley 2015 THD Multimeter with a low distortion sine wave generator, but it is only capable of 0.03% THD at 1 kHz.
It was time to see if I could build something for under $100 that would meet my needs.