How much improvement in digital front ends?

The Marantz repair, which it turns out from other owners is not unexpected, has forced me to put an old Denon 2900 into service again as my main player for the foreseeable (I am resisting temptation to purchase a new Oppo or Sony for purely financial reasons). First blush, it's a step backwards: clarity lessened, somehow the soundstage is not as real as with the SA11, but, and it's a strange but, over a couple of days, and with a Virtual Dynamics David PC added to the mix, the Denon sounds pretty good. Not so much a lesser Marantz, more a different sonic picture. Of course, the players originated from similar eras, 2004 (denon) to 2005 (marantz) but they differed cost wise by an order of three, at least. Other than sonics, which are better, the Marantz has a far more elegant feel in use and tends to load faster. Still, it confirms my view that money thrown at the digital front end is not as effective as money spent on a good preamp or speakers.

Of course, this is a lesson I should have learned the first time I seriously upgraded a CD player. I'd been a slow adopter, even being lectured by a Naim dealer in the UK when I lived there who like me was a vinyl addict, upon hearing my reaction to his carefully arranged demo of the first Naim CD player (a company slow to launch this line and who trumpeted their audiophile credentials for delaying it until the early 90s) said that if I did not like the Naim then I'd never like CDs. Well, he was wrong, and that early Naim player was an ear-ache to me (Sorry Naim, I love you really). Fast forward to living in the US in early 90s, and unable to buy new vinyl, I conceded defeat and went to buy a CD player. I ended up with an entry level Rotel, unable to tell the difference (again to the dealer's annoyance) between it and his more expensive models. It was fine, for the time, and I still have it, but bombarded by the audiophile media through the 90s that I needed a DAC or a new high end player to really appreciate digital, I succumbed to a two-box Parasound set up. Oh dear. It was really not much better than the Rotel, even though the cable connecting the two cost as much as that player.

Long story short, the Denon 2900 replaced the Parasound, with a simple return to one-box, and sounded better. The Marantz sounded a little better again. How many dollars could I have spent on other parts of the rig with better return? Don't ask. So, just how good is that Oppo?