THD is usually shown in negative dB. Most differential op amp datasheets only show distortion caused by the 2 nd harmonic (HD2) and 3 rd harmonic (HD3), as these are the main sources of distortion.

Calculating it is a complex mathematical operation (explained in depth here), but to put it very simply, 1% THD is -40 dB below the original signal, 3% THD is about -30 dB below, 10% THD is -20 dB ...

The recent Design Idea “Getting an audio signal with a THD < 0.0002% made easy,” discloses a low THD sine generator which led me to dust off a design that I had published in AudioXpress magazine [1] ...

New operational amplifiers optimized for high-performance audio and ultrasound applications combine extremely low total harmonic distortion plus noise (THD+N), -130 dB, with large output voltages ...

The SABRE9601 Headphone Amplifier delivers an unprecedented performance level of 122dB DNR and -117dB THD+N, making it the perfect companion for the critically-acclaimed SABRE-2M series of 32-bit ...

--(BUSINESS WIRE)--ESS Technology, a leading provider of high performance audio/video solutions, today announces the SABRE9602 Headphone Amplifier with an integrated ultra-low THD output switch as ...

THD is defined as ... especially when figures of greater than 90 dB or more are needed. The frequency source must be of a purity exceeding the desired measurement. Plus, the analyzer's ...