Build your own low distortion oscillator!

hagtech · « **on:** 27 May 2003, 10:47 pm »

I dug this out from my archives... Here's a cheap, but very good circuit you can build for creating your own sinewave oscillator. It has a fixed output amplitude and 1kHz frequency. I built this using an OPA2134 (one side) and achieved about 0.01% distortion. Perfect for measuring my tube circuits. Modify as you like.

The frequency is determined by the R and C in the Wein bridge. The secret is the 5W night light lamp used in the feedback for stabilizing gain (Hewlett-Packard fame). My lamp measured about 7 ohms cold. Modify the negative feedback resistor (shown as 1k) for tweaking stability and amplitude.

jh

House de Kris · « **Reply #1 on:** 2 Jun 2003, 08:44 pm »

Thanks for taking the time of posting this. Although you state that it is good enough for your tube gear, do you have a better circuit that is good enough for using with solid state electronics?

hagtech · « **Reply #2 on:** 5 Jun 2003, 07:32 pm »

Sorry, I haven't built anything better than this. Didn't need it.

I used to own an HP8903B which had maybe 0.002% noise floor. Best is to just buy one. I've been trolling for a Tektronix SG505 for some time. I would highly recommend it if you need a super-low source at a reasonable price.

jh