I need a good Preamp

I like my Parasound Halo P5.

@mechans , @wemfan ,
The Atma-Sphere 6SN7 based preamp (UV-1) does offer MM or MC as an option. Its sonics are like a great classic tube preamp, but it’s single-ended, so I recommended the balanced units due to the design of your Krell monoblocks.

I don’t own any PS Audio gear except one of their power cables. I have been over to their headquarters for a tour. Nice people and I bet they are up to answering any questions you have. Here is a review of the PS Audio $6K offering. http://www.soundstagehifi.com/index.php/equipment-reviews/1028-ps-audio-bhk-signature-preamplifier

PS might let you do a buy/try.

I do own a Rogue Audio RP-1 and I am very happy with the product and there are a bunch of reviews on this product out there as well as the RP-5. The RP -7 is their flagship Pre and If you give them a call I bet they might let you do a trial on the unit. The RP -5 got some great reviews as well.

http://www.rogueaudio.com/Products_RP7.htm

I really like the way the RP-1 softened up and breathed life into my class D rotel amp and B&W foor standing speakers.

I have been into Audio for over 40 years and have had every type of preamp 
Out their. The Best I havd found similar to a SET amplifier for only ond stage purity
Is a Direct Heated Triode Preamplifier.  The sonic purity is second to none .
Also when buying commercial built products if you are lucky.just 25% of thd 
Product is the cost to build it a $10k preamp maybe $2-k in parts at best yhe rest overhead ,45-50% dealer markup.
I went yo Audio engineer Radu Tarta,  he built me  a fantastic Dual mono 
Pass labs F6 , then this Fantastic DHT preamp . I get to choose options 
On every level . For example look at your power supplies no name average after best. In hear Lundahl from  Sweden, plus chokes for further filtering  4 pole capaciyors Mundorf or Jensen in the power supply, single chassis or 2 box seperate power supply and still much less money then a commercial unit 
And put it to shame in brand name parts quality. Unless you have tried a DHT preamp in uour system you have not heard it's potential at its purest.
I am having another one built look at even the volume control I have thd Latest Khozmo with remote the ball bearing action ,most gave thd pathetic Alps blue velves you loose a lot of purity evrn through the volume. Slagle transformer volume a little better still but $1-k  ,I took the Khozmo at $400 just an example
Of possibilities and options.  The Only possible down side is if your speakers are 
Super efficient, or some amplifiers gain too high  , thd majority  of equipmrnt 
Are fine. We'll worth inquiring ,.if looking for a fantastic pre with  quality remote 
For $2-k the  fantastic tube 4P1L    Vacuum Tube and name of preamp model.  

I’d recommend looking at Coincident Technology’s linestage. These preamps don't come up on the used market very often for good reason.

Coincident Linestage (uses 101D tubes) $5,000: http://www.usaudiomart.com/details/649343645-coincident-statement-linestage-rare-remote-version-w-upgraded-tubes-and-pc-free-shipping-paypal/

Some reviews:
http://www.high-endaudio.com/RC-Statement.html
http://www.enjoythemusic.com/superioraudio/equipment/0410/coincident_statement_line_stage.htm
http://www.audio-activity.com/coincident-statement-linestage-in-english.html
http://www.coincidentspeaker.com/review_coincident_statement.html