What should I upgrade

Mapman,

I was thinking along the same lines that you are. I think that I could get away with a tubed pre for the reasons that you stated. I've always wanted something along the lines of an Audio Research piece. I just need to find one with remote control.

Bob,

I am getting what you are saying; and the more I think about it, the more sense it makes, especially with that three way speaker analogy.

So...what sort of crossovers are there available? I looked into the NHT X2, but can't find one. What else should I be looking at/for?

Tonyangel,

I agree with the replies that upgrading your dac will not give you a significant improvement, or even much of a change, in sound quality.

I think Elizabeth's and others' suggestion of a tube preamp is probably the alteration in your system that would result in the most significant change in sound quality. I used this strategy about 7 yrs ago (pairing a tube preamp with an Aragon 4004 ss amp) and this made my system more lifelike, textured, 3 dimensional and a touch on the warm side of neutral; just what I wanted.

The heat produced by a tube preamp is low, nowhere near the heat of tube power amplifiers. However, you do need adequate ventilation space around and especially above the preamp for the heat to escape. Nothing should be stacked on top of the preamp. I leave my tube preamp on 24/7, and just replaced the 4 tubes recently after 7 yrs, but this is not required.

I wouldn't change your speakers. Your Silverline Minuets are very nice and you like their sound. For smaller speakers, they're not overly efficient. They have an 88.5 sensitivity rating which means they may benefit from more power. You may want to try a new/used tube preamp with a higher powered ss amp. From personal experience, I know that pairing a tube preamp with one of the newer class D ss amps produces excellent results.

The Minuets are rated at 100-300 watts for power handling. I think your Aragon 2004 is at the lower end of this range, somewhere around 100 watts. Doubling or tripling your power will result in several benefits. The music should sound more relaxed/flowing and the dynamic range should increase. A class D amp will not only give you the added power, it will be neutral and pass along the tube qualities of a the preamp unhindered. Since it produces very little heat, it is also better suited to the confines of an entertainment center (although nothing should be stacked directly above it, either).

Just something to consider.
Hope this helped,
Tim

Speakers. Big tall full range speakers. You are missing the bottom half of the music. You are also missing the larger scale that big speakers deliver. No other change with make a huge difference.