Atma-Sphere MA-2. Ralph Karsten is an outstanding, designer, manufacturer and human being. His amplifier and preamplifier designs are superb, and he's constantly finding new ways to improve the results he gets. Every improvement he creates can be implemented as an upgrade to any prior model, and with an upgrade to current factory spec comes a full new warranty. There are not many manufacturers out there taking care of their owners as are Ralph and Atma-Sphere.
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