@nonoise - if you believe the rest of your system is up to par, you could try a Furutech fuse in one component (such as your preamp), and then go from there. You may decide to convert to Furutech one component at a time. However, like I said, the Furutech is very much a DOUBLE EDGE SWORD. It can reveal every little problem in your system. It will reveal poor quality electrolytic capacitors that contain a lot of electrical resonance and all of a sudden your system sounds too bright and harsh. It can reveal speaker drivers that are ringing/break-up/blare because now your system is so strong that it has a rock hard muscle moving these speaker voicecoils. If you are ultimately after more resolution, air, extension, decay, deep bass resolution and punch, etc., the Furutech may be your end-game and I believe the work is worth the effort. However, it can be a lot of EFFORT!.
The SR20 is very clean and I have seen it excel in tube electronics. Listening to it, I think there is somewhat of a roll-off in the very high frequencies, so you will probably not get as much "air" and "ambience" as the Furutech. The SR20 are 60% off at Parts Connexion right now (clearance sale), so it might be worth it for $23 a fuse to try them out.