Tube Amp Doctor 7025WA / 12AX7 Premium Selected Vacuum Tube The TAD 7025 WA delivers full gain with smooth top end. No microphonic issues even with the most sensitive preamps. The 7025 WA supports a fat midrange and creates a bold tone with lots of overtones. Played clean the TAD 7025 WA delivers a warm liquid tone which is very responsive to dynamic playing. Overdriven the 7025 WA provides lots of sustain with well defined mid-range punch. Recommended choice for most demanding guitar amp input/V1 stages