OSRAM Z729 / EF86 – MATCHED PENTODE PAIR (2 PCS)

Up for sale is a matched pair (2 pcs) of ultra-rare vintage NOS Osram Z729 / EF86 low-noise audio pentode vacuum tubes, supplied in individual white boxes. Made in England, these legendary British audio valves feature iconic Osram badging, mesh plate shielding construction, and top square getters. Worldwide recognized by audio purists, studio recording engineers, and tone connoisseurs for their extraordinarily quiet noise floor, lush midrange musicality, exceptionally low microphonics, and smooth frequency response. An elite-tier matched pair upgrade for Vox AC15/AC30 V1 input channels, high-end tube preamplifiers, and vintage condenser studio microphone circuits.

Both tubes have been fully tested on a precision Amplitrex AT1000 tube tester. Measured Plate Current (Ip in mA) and Mutual Conductance (uMhos) alongside percentage performance ratings relative to nominal factory reference specs (Reference: 3.0 mA / 1,800 uMhos) are detailed in the table below.

Technical Note: Custom duties and taxes are the responsibility of the buyer in their country.