My first preamp was a Classe DR-6. I used it with a Classe DR-15 amp. I was pleased with it but wanted something new, so I sold it. That was probably 20 years ago. I do recall it was well-built, and well-reviewed at the time. The guy who bought it was thrilled to get it from me. I see them sell today for more than I sold it for, which may be an indication of how well they have held up.