Has any audiophile fellows compare the sound.

I actually own both a REF 75 and a DS 225 - not quite the 450, but I doubt the difference in sound between the 225 and 450 is meaningful. The 225 has a more solid, well-defined bottom end, but is a little brighter at the top. Just about exactly what you would expect for vacuum tube vs. solid state. But the Ref 75 has plenty of bass and is silky smooth from top to bottom -- and has better imaging than the 225. All in all, I spend way more time with the 75 in my system than the 225. I also love the fact that the 75 can be biased from the front panel (unlike most ARC tube amps), and that when it is time to replace the tubes, I can get a complete set of replacements from either Tube Depot or The Tube Store for under $250.00.

Dear Rdavwhitaker I went to visit with my friend and him an I started to listening to music he has a REF 75 with a LS 17 pre amp and B & W speakers and the sound was fantastic exactly the way you describe it.

I was happy with my systems until I hear how wonderful the REF 75 sound to me.Yesterday afternoon I went to my local dealer to pick up a REF 75 and compare it to my DS 450 but I knows now which one is the best of the two. I will report to you what I found. Juan.

I have the REF 75 and it is a fantastic amp. BUT ... you haven't heard what is can really do until you change out the KT 120 tubes for KT 150's. This is a major improvement. The tubes are available from upscale audio. If you go with the 150's, you'll have to leave the cover off of the amp as the tubes are a little longer than the 120's.