FFT Software Spectrum Analyzers

[ZeusMC]

Are any suitable for tube circuit development?

Thanks.

[K O'Connor]

Hi Guys

Any design or measurement software suitable for audio is inherently suitable for tube audio.

A friend of mine uses True RTA, a real-time analyser on his computer; see trueaudio.com. he thinks there is a better software from audiotester.de but has not used it yet.

Note that any computer-based measurement software is limited by the sound card in the computer. For THD you have to be as close as possible to the maximum amplitude allowed to get any sort of acceptable figures and this is tricky since there may be no way to know what level the sound card clips at. The RTA is doing relative measurements so it may work well enough to see certain aspects of performance and is likely more limited by the noise floor of the sound card. The problem in general with computer-based testing is that the sound card is not gain-calibrated. Bandwidth is another concern for high-end audio but maybe not for testing guitar amps.

Have fun

[ZeusMC]

OK thanks Kevin. I'll check it out.