ZX Spectrum +3 Sound Distortion Analysis and Fix

We revisit the Sinclair ZX Spectrum +3 we fixed a few weeks ago and we attempt to improve the quality of the sound output. We compare the sound the AY chip produces on the Spectrum +3 to the Spectrum +2. We record some test sounds and compare the sound waves produced on the two computers. We look at the sound amplifier circuit on the +3 and attempt to make sense out of it. We look at the AY signal and the amplified signal with an oscilloscope. Then we model the amplifier on a circuit simulator and attempt to fix the clipping problem. Finally, we make a few minor changes to the +3 sound amplifier and run some tests. Support Noel's Retro Lab on Patreon: https://www.patreon.com/NoelsRetroLab Links: Original Spectrum +3 amplifier circuit: http://tinyurl.com/vmtcsaq Fixed amplifier circuit (similar to Spectrum +2): http://tinyurl.com/qu4kx68 Music: Glider Rider https://spectrumcomputing.co.uk/entry/2054/ZX-Spectrum/Glider_Rider Astro Marine Corps (AMC) https://spectrumcomputing.co.uk/e