(SOLD) KR Audio PX4 Riccardo Kron Limited Series matched tubes in excellent condition. Used less than 300 hours on my Lampizator DAC under low heat. The regular KR PX4's are not even close to these RK limited edition tubes. Retail new $1,100. Asking $750. Paypal add 3% or no fee f&f.
Technical highlights:
• Improved structure support in the least vibrating glass points with double mica
• Ceramic bases
• Gold plated base pins
• Triple thickness glass
• Doubled cooling radiation surface for anode cooling
• Barium heaters that run colder and have better emission
• Closer tolerance matching
• 9th degree of vacuum for extended longevity
