Round 2 at my amp techs,, he had to convert the DC power supply biz to get rid of the hum.. I'm not an amp tech, all I know is $80 more and it's golden. Never heard an EL84 amp sound so much like a 50 watt Plexi (or better). My 6545 always ran on the bright side of things. The RX is nice with the ability to dial the top end out a bit when using a Tube Screamer or Barber LTD in front of it. Yet it still retains killer Midrange.. The RX breaks earlier than most non MV amps. Pretty much my dream amp for that reason. I still love my Route 66, but don't see myself playing it much since I got the RX. My SG Standard, THD 2x12 cab & the RX is a perfect match.
If you like articulate tight low end and an amp that cuts thru any mix. Find an original RX.