Zenductor 2 Amp Camp '24 version

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...).
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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.
 
If you are industrious, energetic, and highly motivated, you can lay out a clone of Nelson's PCB. His project description report includes a nice two-color diagram of the PCB, so you can copy the parts placement and the routing of the copper traces, from Nelson's original PCB design. It's attached to this post in the BA2024 thread. You don't need to design a PCB, Nelson has already done that. You only need to copy a PCB, which is faster and easier and less error-prone.

Then you have the option to purchase ten or fifty PCBs, use a few of them to build some Zenductor2's for your own use, and then sell or give away the rest -- to very thankful recipients.

I wrote a little tutorial about having PCBs made at a fab shop, here is a link: Ordering PCBs online (using Gerber files): A walkthrough -- featuring the fab "JLCPCB"
 
That's great, thank you Mark.

The problem for me though is scarcity of time available to do that.
I am about to start pruning my 6 acre vineyard, drive a huge number of posts in the ground, run wires and convert 2 blocks from bush vines to double Guyot, all in the next 3 months, hence my question.

I'll probably build it on a strip board as I've done with a lot of other projects.
 
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Post #286 of this thread suggests a build procedure which does not require you to wait for other people to eventually bring out kits, parts, documentation, and subsystems -- available for ordering. You put forth your own effort and you reduce the uncertainty of when-will-piece-X-be-delivered-to-me.
 
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