I have xr45 & 50. The 45 fan does cut in but the unit stays really cool. xr50 on the other hand with no fan warms up like conventional fanless amps. I think Panasonic determined that the receiver could live with the added heat and that a cooling fan wasn't needed.
Neil,
Could you give us your take on the sonic differences between the XR45 and XR50, please ?
I have lots of earlier posts here and on AVS but in short I thought the xr50 sounds either a little sweetened or a little sweeter, though I'm not sure which. Let me explain - some sounds on the xr50 sound splashier and with a touch more of the sound that's described as 'warm' or 'rich' on analog amps. Now does that make it the better sounding amp? I'm not so sure, because it almost seemed to me as if the xr50 might have been tuned to sound a bit more this way. Those preferring a very neutral and unmodified sound might prefer XR45 which doesn't sound this way.
To oversimplify it, it would be like how a stereo with bass & treble boost might give the perceived or superficial impression of being better until you do some real rigorous listening.
Last spring I did extensive listening tests including one with 8 various musical passages. The test was around seeing if new XR50's needed 'breaking in' but also included observations as to whether XR50's sound different, better, or worse than XR45's or XR25's.
In my conditions, XR45 was felt to be preferable in 5 of the 8 passages. XR50 was overwhelmingly preferred for looks and ergonomics.
I was not able to discern significant audible difference between xr25 & xr45 incidentally even though we know xr45 has the superior electronics including power section. Perhaps my conditions or speaker selection werren't such to prove any difference between the two.
XR45/25 were easily noticed as different from XR50 between even casual non-audio enthusiasts. There wasn't as much consensus about which was better between the two. In both subjective and A/B blind controlled tests, new out of the box XR50's were less preferred than used Panasonic receivers of both the old and new series.
I still have an XR45 that I'm selling for space considerations but I afraid sentiment might prevent me from going through with it. It remains the favorite amp I've ever owned.
