A few clarifications from a German audiogoner: The amp you are talking about is not called RG4, but RG14. Older versions can be upgraded to the newest version MkIV. The engineer of Symphonic Line always was, and still is, Rolf Gemein. Mr. Lindemann was, and is, the engineer of his equally successful full line of high end audio amps, CD-players, and speakers. Symphonic Line has its own website, which so far is in German only, but the pages of which you can easily translate with the help of http://www.babelfish.altavista.com/
Last but not least, German high end magazine Stereo compared the new version to the older ones in its new May-issue and found the MkIV being noticably better, rating him as "excellent".
Last but not least, German high end magazine Stereo compared the new version to the older ones in its new May-issue and found the MkIV being noticably better, rating him as "excellent".