I still own and use a McIntosh 2105 that I have owned since 1976. It has shown the door to quite a number of other amps that I hoped would be better. I do switch it off now with a recently purchased Audio Note Kits EL34 amp with C-core transformers, but the Mac still bests it in certain ways. A few years ago, I had the transistors replaced along with the big power supply capacitors. I sacrificed the option to have 4,8, and 16 ohm taps, and had my Mac tech install modern Cardas 5 way binding posts and new high quality gold plated input jacks. I also had the an IEC installed so that I could use aftermarket power cords. All of this really didn’t cost that much, and for those who aren’t collectors, and actually just use these amps to listen with, I would say take the plunge and try these modern modifications.
The old power cord is in no way worthy of any good amp, and it is such a pleasure to now have modern 5 way binding posts instead of those crowded, corroded old strips.
I just want to add that for all of those who want to pipe in and point out the technical deficiencies of this old amp, I agree! It is not even close in technical sophistication to modern amps, like the Pass Labs 250.5 that it embarrassed, but as always, the proof is in the way it actually sounds.