Soooooooo many possibilities...!

Actually going to search right now to see if anyone in my area has that Manley Steelhead to demo!
Keep the suggestions coming though!  Paying close attention to all:)

ayre is solid state
and fantastic 
Aesthetix might suit you
the big hi end two box VTL is pretty special IMO
Lamm gear sounds great
i have a REF5se, tell us a bit more about what you found lacking in REF6

enjoy the search

i have done fair amount of business with Audio Classics..great people there

+1 on Manley Jumbo Shrimp/Chinook combo

I recently sold my C47... the DAC was very good sounding, but the phono stage was merely ok.  

The one piece of audio gear that I wish I’d never sold is the Atma-Sphere MP-3, and I would recommend an audition. Very quiet, and the soundstage is fantastic. 

Audio Research Ref 6 has not sold me

Just curious; which interconnects did you try with the Ref 6? Did you run balanced or RCA? If you go to the Cable forum and read the recent "Balanced Cables" thread, there is some great information from Ralph of Atma-Sphere about the XLR pin standard and the undeniable fact that many amp and preamp manufacturers do NOT comply with the standard for various reasons, some good and some not so good. So, ARC, despite their lofty reputation and perhaps for very good, rock-solid reasons, does not comply with the established XLR standard (this is IF Ralph is correct-when I contacted ARC directly as a Ref 6 owner, they refused to comment!). If ARC had complied with the standard, in all likelihood the quality and design of the XLR interconnect would not matter that much but because they did not, it does matter. A lot. I have a Ref 6 and a Ref 150 SE. The manuals to each emphasize in unusually strong language that the owner should use the very best IC they can afford to extract the full potential of the two pieces. The manual does not make any distinction between XLR and RCA. The Ref 150 SE is XLR only, the Ref 6 offers both forms of outputs as you likely know. I tried five different XLR's at various price points and heard tremendous differences among them. 

Glad to hear you like the Steelhead (thats what I meant in my other post not stingray), I’m sure Kevin Deal at Upscale audio would make you a great price on one,he sold me my chinook, if you decide in the end to buy one. The Steelhead is a phenomenal device, I wish I could have gone that route, but I am very happy with the Shrimp/Chinook. Also, did I mention how fantastic Manley Labs customer service is? Great Company to work with if you ever need too. Plus they sell tubes too.


https://www.upscaleaudio.com/


Matt M