Audio Research Corp Ref 5 SE

Hi ,my pre was starting to shine at 400 hours,at 450 it is still getting better and sounds alot different.Can't wait till 600.I would like ask,with this pre,do we need to add a power cord with sonic spectaculars.My tara labs air,has no sonic signature,just delivers good clean reasonibly fast power.So the pre is delivering the goods on its own,the way it should be, I suggest.Im interested in your thoughts as pc have come along way over recent years.Do I fix something,not broken,in that department.I do plan on holding onto this pre for along time,as its the best I've owned ,by a long way.My next best,imo was a ls 15.

I'm breaking in my upgraded phono 2SE. Right out of the box it sounded wonderfull for some hours: transparent, detailed with slam and a very present bass. Then the sound collapsed. After 600 hours the heights and mids are wonderfull, but I'm still missing the bass: ok it's detailed but it seems to stay behind some db's.

Brill, stay with it. My Ref 5 SE sounds great! I've got about 700 hours on it.

@Bifwynne. Is the bass the last to snap into place?

I don't recall. At this point, I think the whole presentation is quite impressive. Just curious, what's the input impedance of your amp? Is your Ref 5 SE driving anything else like a sub woofer? As an fyi, most ARC line stages, incl the Ref 5, should not be driving a combined load of less than 20K ohms.