I was wondering if you have any hiss, coming from your amp, when the volume is turned up, but no music is playing.
It's kind of strange, because my DAC3 was deadly quiet.
One thing I did notice was that, if another cable was plugged into the DAC3, (in your example it would be the playstation) then I found it decreased the quality of the output on the DAC3, even if the other item was off. By the way I noticed this with my MBL DAC also, maybe it's me.
I have a Wireworld gold digital Coax on hand that I use on a squeezebox in the bedroom, I thought it sounded a little thin and lean in my opinion. I have tried it on the DAC3 when I owned it, and I've also tried it on the MBL DAC and I've compared a few other high-end digital cables and the Kubala Emotion AES/EBU is absolutely phenomenal and it's the best one i tried, including some others that were double the price. I actually kept it even though I went to a much more expensive MBL DAC. It is very balanced from top to bottom, very musical, analog-like, and involving, with deep tight bass, with a very dark background that is inaudible. It has resolution and transparency without sacrificing musicality.
I also felt that the DAC3 sounded better driving an Amp from it's balanced outputs.
If you ever get a Preamp, remember to put the volume all the way up on the DAC3, before pressing in the fixed volume button in the back of the unit. It makes a huge difference.
Good Luck, If you decide to go with the upgraded power supply. I agree with you that it usually helps, however keep in mind that Bel Canto Gear is pretty robust already.
Regards,
Rich