Let's keep the parade of old Italian amplifiers going. This is a very small and lightweight combo amplifier from, I guess, the late 70s. The circuit board is visible and appropriately tiny; it features both mains and battery operation, either from the internal holder or from what's basically a DC jack.
Since it's hard to even come up with a picture of it, here's one.
Here's my traced schematic. I knew this wouldn't take much time and I feel confident about it, although the usual disclaimer about accuracy is repeated, since it's reverse engineered.
Main points of interest are:
The power switch chooses between battery, mains, or off. It's actually a 4P3T rotary switch, which FBT seemed to like a lot in that period. I've drawn it in separate sections.
Nice series-shunt feedback input amplifier.
Who said that old transistor amplifiers have to be muddy and unpleasant? This amplifier goes from bright to brighter thanks to the tone control being a low shelf, the bright cap on the volume and the small speaker. This probably comes from the (agreeable) assumption that most guitars have a way to cut treble, but not a way to cut bass.
The TDA2020 chip amplifier is marked "Italy". Cute and nostalgic.
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