The “new” amplified I prototyped probably isn’t required, and it is not quite right, in terms of design, due to the reliance on a double-ended power supply and amplifier configuration. The single supply amplifier design from the other week was tweaked to amplify at 10x, rather than only 2x, and the result is a maximum Vpp of 1V, which is the current target.

These oscilloscope pics show the original and then output signals, along with the iPhone playing the constant synth sound!