I'm a binge listener; I can go months without firing up the system. A disc on the JVC micro system or college radio on same. A binge started a few weeks ago. Some years back I decided that I should get a new player, since the Adcom GDA-600 was already old, and the Yamaha player even older. It came down to the Apollo and the similarly priced Rotel (forgotten the model).
What finally got me really irritated was a tilt in the soundstage: hard left way above the ear canal and hard right well below. Either headphone or either amplifier, tilted. Could be some issue with the Apollo's DAC, long since past warranty. So, I had the 600 in storage, and got it out and hooked it up.
WHAT???!!!
I paid $$$ for the Apollo, which sounds like crap compared!! Thus, I did some searching, and found a thread (search "mod adcom 600 opa627") on a similar site about modding the 600, from a few years ago. Which led to the (re-)discovery that the 600 is among the last DAC/players with ladder DACs, BB CPM63. Which led to other threads. Consensus, and boy howdy is it true, delta-sigma bites and good multi-bit ladder rules. Still. And, it seems, only D-S DACs are current production.
So, if you've got (or can get) an end of production 63 or 1704 (BB; don't know about the other manufacturers) DAC/player, do it. Then go find some place that tells you how to upgrade the PS capacitors, and as that 600 mod threads describes, may be upgrade the opamps.
Delta-sigma bites. Cheap goods sold dear.
