The Dynaco Stereo 70.
I built one from a kit when I was 14 years old. I used it for 12 years before switching to a pair of Dyna MK IIIs, then a larger Hafler. I cannot say the latter two were improvements. I now use a pair of NYAL Futtermans OTL3s.
The simple design has stood the test of time. There are now many excellent mods of it available for $800 - $2,000 range.
imho one of the all time classics - David Hafler was brilliant - and still a good amp esp for the money.
However.
It’s not integrated. The Dyna PAS preamp has also been souped up by current engineers/hobbyists. Pair them together for a classic look and sound.