The TAD 6V6GT-STR “Redbase” Premium tubes showed up and I got them installed in the 6V6 Curly Maple amplifier. I took new voltages and have been listening to the tubes with a variety of music. These tubes are very detailed and musical. They produce a stronger bass than the 6V6Gs and a very even tonality in the ultra linear topology. I would consider these a nice upgrade for any 6V6 amplifier.