[zeke]

I have been listening to the 550exr with the rev5 upgrade for a couple days now. IMO, and in my system, it is an improvement.

The highs are "more" and sweeter. The cymbals have more shimmer and decay -- and are more natural sounding imo.  The low volume level "background" highs( micro highs  ? ) are now more hearable ---  before i thought they were slightly attenuated.  So overall there is a tad more detail.  

The low frequencies are still great, but maybe have a little more "clarity" .

The mids are too tough a call imo.

Please understand that these comments are based on "aural memory", and not a direct comparison between two amps.  YMMV    

Hope this might help someone that is considering this upgrade..........

[vrs]

Any plans to make the R5 upgrades available to Omega Star solid state power amplifiers in future?

[avahifi]

The Rev5" upgrades only apply to the Fet Valve hybrid amplifier circuits.  The OmegaStar solid state units are a completely different design and technology and the Rev5 things do not apply at all to them.

Frank Van Alstine

[Dan Kolton]

I just got back my 550EX with the Rev5 upgraded from R.  I first played a CD with a duet by Bryn Terfel an Cecilia Bartoli from Mozart's Marriage of Figaro.  I felt like I should invite them both to stay for dinner as long as they were already in the room.  Next, I played a CD of a capella choral music by a group in which I sing (I'm on the recording).  This sounded so real, and so good, that it literally brought tears to my eyes.  Kudos, Frank!  You've done it again!