I own a pair of original Marantz 9's that have served me extraorinarily well for over 20 years. They are no longer original because key resistors and capacitors have been updated, the power supply has been modified and the input filters and volume control bypassed (with significant improvement to the sound quality), but the original circuit is otherwise unchanged. I listen almost exclusively to acoustic music, and these amps have a truthfulness to the overall timbre of instruments, and a magic to the recreation of harmonic overtones, that have kept me with them over the years. Only in the past month have they finally been replaced in my system with a pair of Atma-Sphere amps.