The “Premium Selected” tubes have passed the following tests: low noise, microphone, gain, sonic, shock, listening, and balanced output.
The TAD ECC81 / 12AT7-Cz is selected in order to achieve tubes that offer a balance between triodes, making it ideal for preparing the signal before being amplified. Its powerful character makes it perfect as a preamp tube or as a phase inverter to improve dynamics in the amp stage.