Mullard 12AX7 Audio Preamplifier Valve - Part # 12AX7-MUL
Sovtek 12AX7 Audio Preamplifier Valve - Part # 12AX7-LPS
Electro-Harmonix 12AX7 Audio Preamplifier Valve - Part # 12AX7-EH
Quad Matched Set JJ Electronic EL34 / 6CA7 Audio Output Valves - Part # QD-EL34JJ
Tube Amp Doctor Premium Matched Quad Set of 6L6GC Audio Output Valves - Part # RT104