The KBA75 that tweak1 mentioned for sale was probably mine. I rebuilt one myself and sold it just a couple of weeks ago. This is truly a gem of an amplifier. It has a warm delicate nature, yet still very good detail. The buyer gave feedback that the amp is outstanding.
Another old amp if properly rebuilt that is Equally good is a Sumo Nine. Beware without the boards having several parts replaced, it will not be in the league of the KBA75, but when updated with quality parts, this old amp is Excellent. A few last amps that you don't see mentioned often is a Muse One Hundred Sixty, Followed by a Muse One Hundred. I Also rebuilt an old Heathkit AA-1600 from top to bottom. Never hear anything about this old amp, but also Excellent. As with old amps, at a minimum power supply caps should be updated and most likely much more.
Another old amp if properly rebuilt that is Equally good is a Sumo Nine. Beware without the boards having several parts replaced, it will not be in the league of the KBA75, but when updated with quality parts, this old amp is Excellent. A few last amps that you don't see mentioned often is a Muse One Hundred Sixty, Followed by a Muse One Hundred. I Also rebuilt an old Heathkit AA-1600 from top to bottom. Never hear anything about this old amp, but also Excellent. As with old amps, at a minimum power supply caps should be updated and most likely much more.