Two things I learned last night.
#1. Guitar and electronics talk that I'm fairly certain is very oversimplified.
When I built El Presidente, my cigar box guitar, from a kit, it included a piezo pickup (for our purposes, it detects vibrations on surfaces (like, say, the top of an acoustic guitar, and turns them into sound) . Unfortunately, piezo pickups have a very unfortunate reputation for having a kind of shrill tone.
This is due to two factors: 1) The disc is prone to resonating at a specific frequency which is honestly pretty high, and 2) it acts as a capacitor and turns the first input it's plugged into into a high-pass filter. So, when I plugged it into my Pignose (my main amp at the time with its low input impedance), it wound up pretty shrill. But when I got my first Joyo AC-Tone, it sounded a hell of a lot better. At first, I assumed it was because I finally got the Vox tone I had been hankering for for well over a decade. It turns out it was for two simple reasons: First, the input impedance to the AC-Tone was a Hell of a lot higher than the Pignose. If the high pass filter equations and the specs I found are accurate, this is more than enough to allow the entire audible frequency band to pass (with it reaching 20 Hz before even losing a third of a decibel). Second, after some sleuthing and as much research as I've been able to find without just opening the bloody thing up (because it would be a real fucking drag), and after looking up the piezo discs used by the same guys who created my kits,
I think I found the actual discs used. The resonant frequency: 3 Kilohertz (+/-.5 KHz). By an extraordinary stroke of luck,
the specs for the pedal the AC-Tone is based on state that the treble knob is centered on 3.2 KHz. So I could turn the highs down and it sounded a lot better. Shortly after this, I discovered
the Equal-Loudness Contour, and it turned out that, because this was also around the area where the human ear is most sensitive, this seemed to explain why those frequencies were so prominent. In addition to turning the treble down, I started to crank up the bass (which would presumably counteract the residual high pass filter effect that may still be going on, even with a 28nF/1M filter.) Turns out I was right for the wrong reasons! Also explains why, even after getting a Vox VT20X, I was actually less satisfied with the tone than I had been. The treble knob on that did not work as well with the amp than it did on the pedal. Perhaps if there was a cut control like on the actual AC-30 (which tames the high frequencies), but there wasn't.
#2. This is one of my favourite love songs:
Apparently it was originally called "Lydia," not because of anyone in the song, but because the chorus was lifted from a book called
Love for Lydia. Order placed!