My experience is "spot on" with Tubegroover. If you can find a ZX270, by all means try it. For me it is almost unbelievable that such an un-imposing little box can do what it does. I purchased the amp a few years ago and have never even bothered to open the cover, let alone replace the tubes. I don't even know what tubes are in it, and don't care. It's my only component that I get anxiety when I think I may someday have to risk shipping it back to Berning for something or another. Will probably drive it to Maryland if that day ever comes. Bridges best of tubes & SS.
Merlin VSM-mm master upgrade, Herron pre, Berning power, CGR cables
Merlin VSM-mm master upgrade, Herron pre, Berning power, CGR cables