This is a carefully selected pair of vintage EF86 / 6267 low-noise audio pentodes manufactured by M.B.L.E. in Brussels, Belgium, within the Philips/Mazda production family.
The pair is electrically impressive and cosmetically understated. It is intended for the buyer who values verified performance, close matching and authentic European construction more than decorative glass printing.
Both tubes were marked NOS when selected from inventory. Those exterior inventory markings were removed during careful cleaning before the final photographs were taken. Both tubes test at or above the Triplett 3444 average-new reference.
The exact numbered tubes shown in the photographs are the tubes the buyer will receive.
These tubes were selected together because they share closely matching construction:
They are also closely matched electrically.
Tube #1
Tube #2
Triplett 3444 reference
Both tubes test at or above the Triplett average-new reference.
Their transconductance readings differ by only 100 µmhos. Based on the pair average of 2,100 µmhos, the measured transconductance spread is approximately 4.8%.
The pair was matched primarily for:
Both tubes were individually verified:
Tube #1
8Y identifies the EF86 type
L identifies M.B.L.E., Brussels
Tube #2
The Philips factory-code reference identifies L as M.B.L.E., Bruxelles/Mazda. Its newer date format uses G for July and the final digit for the production week.
The original commercial brand stencils are no longer present on the glass. Tube #2’s etched production code is faint, and the pins show normal vintage surface aging.
These presentation details are clearly shown in the photographs and are reflected in the asking price.
In return, the buyer receives a carefully documented pair with strong measured performance, close transconductance matching, verified low-noise operation and highly consistent internal construction.
The EF86 / 6267 is a high-gain, low-noise pentode used in selected:
The EF86 is associated with selected Vox, Matchless, Dr. Z, Quad and studio-preamp applications. Equipment compatibility should always be verified before installation.
Vintage Brussels-made Philips-family EF86 tubes are often sought for a presentation described by listeners and dealers as:
Sonic results depend on the circuit, equipment and complete audio system.
The box numbers correspond directly with the measurements and photographs.
Carefully packed for secure shipment.
Results reflect measured performance on the Triplett 3444 at the time of testing. Exact pair documented in this sales listing.
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