Quote:

I had an Onkyo 838 receiver

the improvement was obvious to everyone who auditioned it - sound was cleaner, less distortion, livelier, more accurate, etc. Nice soundstage, good depth. Music and movies both sounded better.

So in my experience, yes, upgrading from a receiver to separates, at least with a distance in price, is well worth doing and can add quite an improvement in sound.

Besides difference in price, there is a difference in model year. I understand the Onkyo 838 receiver was first made sometime around 1996.

In general, upgrading from a receiver to a pre/pro should in general lead to improved sound, even when they are both current year models. But upgrading from an older receiver to a current model pre/pro should lead to as you said, quite an improvement in sound.

Will