Kr Audio Kronzilla vs Atma-sphere MA1?

I would like to add one facet to your list of pros/cons - the companies themselves. After all, when you buy a product, you are buying the company. Oftentimes, down the road you will need to interact with the distributor and/or manufacturer for repairs, service, upgrades, or even just for information or recommendations.

To me, there is a monumental gap between the two companies. On the one hand, Ralph Karsten has spent nearly 30 years building an impressive track record of customer service, and being there for his owners after the sale regardless of whether they purchased the component new or used. There has also always been a definable and affordable upgrade path available to owners as the circuit evolves and improves.

I don't want to say too much about KR Audio in this particular post, but the erratic/eccentric reputation of Dr. (Mrs) Kron precedes her, and if you put some research into it, their US distribution will also raise a lot of questions in your mind.

I echo Trelja's thoughs and warnings, having owned a pair of KR 6000 monoblocks. I went through several of their VHD842 tubes which I bough new and they turned out to be faulty after about 100 to 200 hours of play. If you do go the KR route, and if you get new tubes, make sure you send in the warranty card immediately, or they will never want to know you if you run into trouble later. Also, I recommend biasing the amp(s) lower than recommended - they will last much longer. don't kid yuorself into believing the tubes will last 10k hours - I think it's nonesense and a loose rumour/promise. If the stars align, the KR amps sound great (I miss them in many ways), but I cannot recommend them, alas.

Atma-Sphere For sure.

I have been working with Eunice at KR and speak with her several times a week for a couple months now.  I was introduced to them via Renaissance Audio in Ann Arbor who I am using as my approved service center and is an outstanding company.  

KR Makes excellent amps and the reputation they have for the quality of tubes and amplifiers is outstanding.  Anybody can have good and bad experiences with a distributor, and yes, they are sticklers for the warranty card being returned.   The quality is excellent.  Return the warranty card and they will honor the warranties without question via a US Service center (Renaissance) that is outstanding.

No one is perfect but KR has been around a long time.  I sell their tubes and will include them as upgrades with Art Audio amps.  I also offer KR Amps to my customers when Art Audio's products don't meet their needs.  For instance, Art Audio offers nothing that can deliver 140w of power like the MA-1.  

How much power do you actually need?  Why these two amps?  What Kronzilla model are you looking at?  Please know there are trustworthy KR Dealers out there and we will stick by you!