upgradeable dacs


I am tired of wasting money on buying dacs to have them be usurped by new technology within a year of purchase. many dacs that claimed being upgradable either were not, or were so expensive as to be not worth it. (original berkeley and bel canto come to mind) Other than the new nad dac line which i think really can be upgraded, does anyone know of higher quality dac products which can be upgraded without any nonsense? thanks
emster
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Empirical Audio Overdrive SE can be upgraded: USB interface, Master Clock for USB interface, Coupling Capacitors, separate power supply chassis and 13 internal regulators. It has already seen all of these upgraded over the last 2-3 years. Since it can drive amps directly, a transformer buffer stage is available to add-in other analog sources as well as bal-SE and SE-bal conversions.

Overdrive has been in reviewer and customer shootouts with all of the DACs mentioned, as well as Debussey, Weiss 202, PD MPD5, Emm Labs, Ayre, PWD, Metrum Hex and others.

Steve N.
Empirical Audio
The technology is changing quickly. Your question is relevant. The issue is whether or not the new DACs sound better to you. The newer ESS chips sound better to some but others like the NOS DACs. Vanilla or chocolate? My advice is that you will have to experiment. Trying to keep upwiththe latest tech in DACs is fruitless. It is impossible for a manufacturer to design a DAC to accept every new chip that comes along. Can you hear the difference? I propose that the software that plays your bitstream may be more important.
What formats are we talking about here? If its just redbook, I'm not sure how much more designers are going to get out of it. Its a pretty mature format. As far as everything else goes, I wouldn't get too worked up over it. If you buy something that sounds good to you now, it should still sound good in the future, even if there are upgrades. Not only that, who's to say the upgrades will be the best sounding option? Maybe in the future, you will be able to spend $500 on something that you like better and costs less than an upgrade. Anything can happen, especially with newer technologies.