Experience with Unison Research Unico CD player .

I have a Unison Research Unico CD player with valve output stage . My other components are ARC LS27 / Ref 150 and Wilson Audio Sophia 2's . My analogue front end is VPI TNT with Clearaudio tonearm and Benz Micro cartridge . Pre to power interconnects are Harmonic Tech MagicLink 2's and speaker cables are Harmonic Tech Pro 9 SE's . Interconnect between the CD player and the LS27 is .5 metre Cardas Golden Ref ( balanced ) . Both the LS27 & Ref 150 are still going through break in ( my prior amps were LS17 & VTM220 monoblocks ) . With the electronics upgrade I'm finding that the CD player sounds great on jazz and vocals but with rock music the bottom end is decidedly lacking in tightness and definition, ' overly polite ' is probably the best way I could describe it . I have heard that Cardas cables can sound very mellow and I'm wondering if anybody has experiences with what cables work well with this CD player . I don't want to swap my Cd player for something else if I can help it as I mainly use it when I am in ' casual listening ' mode and use my vinyl front end for serious listening . Any comments would be welcome and also any experiences with good CD players under $3K or so ... I am restricted to front loading as my CD player is on a middle shelf ... Many Thanks !
What 12AU7 tube do you have in your CD player and have you tried other brands? The most dynamic 12AU7 type tube I tried with a Unico integrated amp when I had one years back was a 1965 vintage Radiotechnique. Very tight and deep bass and also very detailed in the midrange with an extended top end. Not a romantic or warm and mellow sounding tube. Other preferred tubes in this application for a CD player have been the Amperex 7316 and Telefunken 12AU7.

Experimentation with tube dampers such as the ones made by Herbie's Audio Lab could also be beneficial. My experience with these in a similar application is better focus and soundstage, deeper and tighter bass and a generally smoother frequency response. Results may vary. Herbie's products have a 90 day return period so if it doesn't achieve the desired results it can be sent back.
Hi RB , thanks for your response , I replaced the original tubes with NOS TUNGSRAM ECC82 , which are 12AU7 equivalents , I'll try and hunt up the ones you have mentioned and also try some Herbie's dampers . Thanks for your informative response .
Chris .
I found 4 matched Radiotechniques on that auction site , bingo , here's hoping it helps ! Never been to Herbie's site before , thanks for the heads up ! Chris .
To answer the Cardas question yes they are mellow, especially the Golden Refs. Why not sub another IC if you one) and see if they sound better.
For 12AU7s with good definition you want German (RFTs included) if going with NOS . I also love the 7316s for imaging and crystalline top end, but they are expensive.
Hi Mechans ,
Thanks for your reply , I aim to try a 1 metre H T Magic link 2 between Cd & PreAmp , don't have any spare balanced interconnects at the moment . Tempted to try Nordost also but prior experience has shown a tendency towards brightness when used with digital sources .
Regards .