Balanced outputs vs balanced design

my favorite fully differentially balance equipment is maid by montana audio

I own a ARC Ref 3; it is a fabulous differentially balanced linestage, with loads of finesse, micro and macrodynamics; I suspect it will match very well to your Halcro. . I am also exceedingly partial to amps manufactured by Jeff Rowland Design (JRDG) like the Concerto. I have heard it matched to several Rowland power amps--which like yours are class D switching amps--and the results are supremely musical. . . . and yes, Rowland preamps are all completely balanced designs.

Eldartford is correct; choose your components on sound alone, not whether or not they are balanced.

Some of the finest high end manufacturers build only single ended equipment.

An other linestage I have enjoyed very much and may in fact soundly slightly sweeter on the Halcro MC20 than Ref 3 is the VTL 6.5 Mk2 hybrid. . . still a truly balanced design and truly magnificent. Were I now in the market for a linestage I would consider this device extremely seriously as well.
By the way, tell me more about your experience with the MC20: Strong and weak points? what other amps did you consider? Any other digital amps in the race? What tipped the scale in favor of Halcro MC20?

Friends, thank you for the replies and suggestions. I will check out the preamps recommended, though it is apparent that they are a pricey bunch. I think that a used BAT 5VK is more in my price range - or perhaps a used Atma sphere. Missed out on a very well priced one on Ebay (just over 2k). Drats.
Guidocorona, I wish I could tell you that my path to the the Halcro was the culmination of an exhaustive trial of many contenders. But the fact is that I was looking for a beefy amp to drive a pair of Gallos that I was interested in and read a few very flattering reviews of the Halcro which packs a punch at 400 wpc. I also wanted an amp that does not pump out the heat like my Pass Aleph 3 - the "little furnace." I am a musician and was drawn to the transparent qualites attributed to the Halcro as well. Never figured I'd end up with the Halcro given the $5k price tag. But I got a lightly used demo with warranty from a dealer for $2400 on Ebay. It arrived yesterday and have not had a chance to plug it in. My current system is a Pass Aleph 3 and Blue Circle 21 powering a pair of Newform Balance speakers. It will be interesting to hear the difference between these two very different amps. My plan is to build another system, using the Halcro to push the Newforms which are not terribly efficient. So I need the pre for that Halcro set up. And then I will get a second pair of speakers for the Pass/BC. On the short list are Gallos, Tyler Signatures, Salk HT3's, Zen Adagios, or a Zu product. Not such a short list now that I see it in front of me. Unfortunately I live in rural Maine and do not have the luxury of ears-on trials. But I bought the Pass/BC/Newform unheard and have no regrets. I appreciate any thoughts y'all may have on the speaker end. There are those used Zu definition Pro's that look very nice.....