Release 1.160

Release 1.160 (Sept 2022)

This is a pre-release with several new features, including two more visualizers. The visualizers are partially functional at this point, and more capability will be coming in time. UPDATE: The initial release was missing the new visualizers. The release was re-built and the new version is 1.160B. It's in the assets link below and the original 1.160 version has been removed.

• Added experimental 384K ADC mode. Use -384K on the command line to enable. Note that the DAC doesn't work at the 384K rate.
• Added dBVRtHz Y-axis units
• Bumped up font size of X and Y axis, bolded certain text. This is to improve legibility.
• For dark on light display theme, the background was darkened behind the various text regions to improve legibility.
• Fixed bug where dBR wasn't correctly displayed in measurement tile when in DBR Tracking mode
• Logo wasn't resizing correctly when window was resized
• Automated Tests now respect Start/End measurement frequencies. Previously, some plugins would consider as low as 1 Hz, which meant
  you needed a large FFT to prevent the DC offset from spilling into lower frequency bins
• Fixed bug where REST mask test was failing and computing mask pass/fail incorrectly. This fix allows Tractor to correctly work for mask tests on frequency sweeps.
• Update manual
• Tracking improvements for Wow and Flutter to help with modulation effects such as flange/phase
• Added experimental visualizer named "Filter Explorer." This tool aims to make it easy to understand filter performance and order with
  specialized tools to analyze filter plots. Currently, only bandpass filters are supported.
• Added in THD visualizer bargraph. This allows viewing THD components as a bar graph.
• Added "Oscilloscope" visualizer. This allows viewing in the time domain separate from the main display time/freq domain

The THD Visualizer output is shown below. Note the visualizer uses the GEN1 frequency setting as the fundamental. And then harmonics 2 through 10 are plotted. This particular plot is of a guitar distortion pedal. Note that if you pick a frequency of, say, 10 kHz, and you have a 48ksps sample rate, the harmonics will exceed the Nyquist, and an error will be display. So, be aware that you need a sample rate that supports 10 harmonics. Future iterations of the visualizer will allow customization for the number of harmonics

The Oscilloscope visualizer is shown below. There are two vertical cursors, with the ability to drag to zoom. This allows time domain display alongside frequency domain display of the main screen.

The Filter visualizer is shown below. You first select the filter type and then you can have cursors automatically placed. For example, on the bandpass filter shown, a button allows you to move a cursor to the peak, and then another button allows you to find the -3 dB points with two more cursors. From there, Q is calculated. The aim here is to make it easy to look at a low-pass, for example, and quickly learn passband ripple, filter corner, resonance, and roll-off. While this can normally be determined with cursors and a calculator, the tool here automates much of the tedium and calculation required. Currently, the visualizer only supports bandpass filters. More features will be coming.

The Wow and Flutter Visualizer had improvements made to help with tracking intentional modulation applied to a signal. Wow and flutter manifests as frequency modulation. That is, if the hole on a record isn't perfectly centered, then the speed of the record will rise and fall as it rotates, which results in changes to pitch. But certain musical effects for guitar and vocals intentionally modulate incoming signals to make the sound "bigger." In the plot below, you can see an unmodulated signal on the left. While the remaining 3 panels show different types of modulation, including vibrato, chorus and flange.