Replacing my Krell FPB 600 amp with a tube amp

@tattooedtrackman - It appears that your ARC Ref 6 preamp has two variable outputs and one fixed line out for use with a tape recorder.
You pay your $14,000 but you get what you pay for!

I think @rcprince may be right. I have gotten very good results from VTL MB450III mated to my ARC Ref 40 to drive my Q3s. The variable damping factor on the VTLs allows you to optimize for the speakers you are using and address the issues @almarg raises. The VTLs are also very robust with super reliable automated biasing. Even a full on tube failure is handled with aplomb. If you do go the VTL route however you are advised to buy from a VTL dealer as they can be sketchy on support if you don’t have that relationship. Finally make sure to connect the pre and power amp with balanced interconnects.

dweller.... That is correct... I will tell you that this ARC Ref 6 is so awesome in sound that it will very likely be my very last preamp. You must hear it to believe and appreciate it. 

@tattooedtrackman - I believe your ARC is AWSOME! I've had many ARC components over the years and I put them on a pedestal. Can honestly say that my current system meets ALL of my needs. The only way I'd enjoy it more is A. A bigger room (e.g. 25 X 50 feet)  and/or B. Legalized THC. Long live music!

Replacing my Krell FPB 600 amp with a tube amp

REALLY!!!!!!

Haven’t read any of the other posts, all I can say is "YOU"LL BE BACK".
The better I made all my tube amps sound with mods/circuit changes, the closer they got to the best solid state.
The only one that was close/equal to the best solid state was the OTL tubes, but you have to be careful what speakers you drive with them, which are usually the ones I don’t use.

Cheers George