Sure but electronics may add an own, unintended, sound character and decay over time too. In best case it’s only noise, though I’m a bit afraid it would also tweak filter frequencies a bit, not that it would disturb much but if I optimize a track against a corrupted sound then the export won’t be optimal either.

It is exactly what you’ve said, I’m not planning to touch the controls anymore after all is setup, that’s why Im hesitating to go with feature rich and expensive. Hence you didn’t experience any decline in all the years of usage?

Would you say input = output (if, to make it simple, only one channel at a time has a signal)?