I got the cheapest (or only?) 3 wire 3 digit low range meters I could find on Amazon. I was actually looking for 10V range, but these 100V meters can switch their decimal point, so they work. https://www.amazon.com/dp/B0BG31FBX5
Three wire is important, since digital meters will not usually run below about 3V, so you need a meter with a separate power connection. Good thing there were 5 pairs, since one of the green ones already self-immolated (actually, it just went dark, but it did pull its supply voltage down to 2V, and when I then misguidedly (not sure what I was thinking) removed the inline resistor I had wired in to reduce the voltage it was running at, some actual smoke came out...).
Maybe I'll add a parts list to the separate thread.
Three wire is important, since digital meters will not usually run below about 3V, so you need a meter with a separate power connection. Good thing there were 5 pairs, since one of the green ones already self-immolated (actually, it just went dark, but it did pull its supply voltage down to 2V, and when I then misguidedly (not sure what I was thinking) removed the inline resistor I had wired in to reduce the voltage it was running at, some actual smoke came out...).
Maybe I'll add a parts list to the separate thread.
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A quick question: I see third harmonic dominance below about 200 Hz. The crossover frequency point between 2nd and 3rd dominance moves a bit with bias.
Is third harmonic increase expected at low frequencies, maybe due to the interstage transformer?
Of course there's always the possibility of user error, but my measurements seem to generally agree between Analog Discovery 2 + Audio Analyzer Suite and Focusrite Scarlett Solo + REW, and also in broad terms with Nelson's overall distortion graphs in the Zenductor 2 note.
Is third harmonic increase expected at low frequencies, maybe due to the interstage transformer?
Of course there's always the possibility of user error, but my measurements seem to generally agree between Analog Discovery 2 + Audio Analyzer Suite and Focusrite Scarlett Solo + REW, and also in broad terms with Nelson's overall distortion graphs in the Zenductor 2 note.