« The little amp that doesn't have much to learn from the big ones ;-) »

Found at a ridiculously low price (€15), but it's worth much more if you go by the sound quality.

In summary:

It must be about 20 good watts
MIJ in the 70s, maybe early 80s at most?
A standard input, an overdrive (which, in my opinion, is a high-impedance input, not an overdrive in the guitar sense).
A line out, an additional speaker output (which I still need to test!), a headphone output (without speaker simulation, given its age).

The positives:

Clarity worthy of the Fenders of the time (and having owned a Vibro Champ, I speak from experience).
Excellent at taking pedals, especially modulation ones.
A (very) sturdy build.
The variety of outputs makes this Zip 100 an amp you'd want to experiment with a lot!
The active EQ is a joy, making the amp very, very versatile.

The less positive (for the price, I won't call it negative...):

Depending on the cleanliness of the guitar wiring, the buzzes don't forgive... P90 and distortion combined? Forget it
It's a shame the overdrive isn't a true overdrive, that was my only disappointment.

At €15 or even €150, go for it!