811A Penta Labs High Mu Power Triode Matched Pair (2) Tested Tubes

Description

Platinum Tubes
811A Penta Laboratories High Mu Power Triode Matched Pair (2) Tested Tubes
The Penta Laboratories 811A is a high mu power triode designed for service as an audio frequency amplifier or modulator, or as an RF amplifier or oscillator. The 811A is capable of outputting up to 160 watts at frequencies up to 30 MHz. All Penta Laboratories tubes are burned in before testing and matching at our testing facility in Ventura, California.
Orders will be shipped within 30 business days
New Current Production
No returns, however defective devices will be replaced free of charge for 13 months*
Product is manufactured by affiliated or unaffiliated manufacturers in various countries. Country of origin is printed on the tube.
WHY PLATINUM TUBES?
Once purchased and received by Platinum Tubes, vacuum tubes undergo exacting quality control measures to further assure reliable, sonically acceptable performance. Each power tube is then tested and graded for technical characteristics specified by platinum tubes engineers. Only after a tube successfully passes these exacting challenges is it labeled and put into stock to be sold. Tubes not meeting these criteria are rejected to the supplier or disposed of.
Average tube life will depend on several parameters: product type, how the product is installed, loudspeaker efficiency, room size and acoustic damping, listening habits or average sound pressure levels, A.C. line stability and purity, and other circumstances. Generally, preamplifier tubes last up to 5,000 hours, while power amplifier output tubes will last up to 3,000 hours. Near the end of their useful sonic life, aging vacuum tubes may degrade the sonic character of the product(s) they are used in. The sound may become somewhat dry and lifeless, with a noticeable decrease in harmonic richness or bloom. Bass response may be diminished, and musical dynamics may flatten out or compress. Toward the very end of their service life, tubes may become noisy, noticeable as a slight rushing sound or rustling noise. It is far better to replace vacuum tubes prior to the end of their service life, before severe sonic degradation or outright failure occurs. Running vacuum tubes into failure may damage to other internal components and cause needless repair expense.
Factors which can shorten tube life include inadequate ventilation, overdriving loudspeakers at continuously high volume levels, severely fluctuating A.C. line conditions (e.g. sagging line voltage during summer peaks of air-conditioning demand), or severe interference pulses or electromagnetic interference.
*In the event of a failure, tube(s) must be sent back to us at the buyer's expense. We will expedite any replacements after testing the tube internally at our expense.