Helmut80:thanks for all that info pete. Didn't even know DACs could be upgraded. is it as simple as taking it to local hifi store and getting it done, or does it require a personal interest and know-how, because I don't have much patience or interest in fiddling and DIY I am afraid.
I'm the same, I don't trust my soldering skills enough to do it myself. I use Fidelity Audio (previously Audioupgrades), just send it away to them with a budget and any specific requirements and they send it back modded. Brent is the person to speak to there. I've had my DacMagic modded to Level 4 + Burson opamps. My feeling is that a DAC is the ideal piece of hifi to modify. Once you've got a good DAC in your system, you're unlikely to change it too often, whereas CD/Blu-Ray players or amps tend to get replaced more frequently. Having said that, I'm sending my newly purchased Marantz Blu-Ray to them next month for a new clock and some mods to the analogue 2 channel output.
With regard to opamps, when you consider that one of most respected audio opamps in the output stage of hifi is the LM4562 (as used in the DacMagic) which costs about £5.00 to likes of you and I, however, most manufacturers use even cheaper opamps than that. The Burson opamp costs about £120, and don't know if any manufacturers DAC's use this opamp, but I suspect the ones that do would be pretty pricey. Once run in, the Burson opamps give a completely classy sound, they keep the detail of the LM4562, but are less clinical, giving a superb midrange and bass, altogether more musical.Whilst some of the other upgrades produce subtle improvements, the leap forward sonically with the Burson's is unmistakable. I'd say the Fidelity Audio Level 2 + Bursons is the best value.