Description

PAIR BY PERFECT GAIN E188CC VALVO BY PHILIPS HEERLEN TESTED WITH ROETEST NOS/NIB TUBE GOLD PINS Tested With Roetest V10 By GAIN NOS/NIB The Gain parameters is Tub nr.39 μ=33.3 μ=33.3 Tub nr.41 μ=33.3 μ=33.3 . The tubes were produced in 1966.You can clearly see it in the picture The tubes have same codes: 1 PAIR:VR6- Δ6A3 VR6 - Δ6A1 The gain is the parameter that mostly affect what we hear from a preamp/amp. Using tubes with the same gain lead to same sound level from each channel. We removed tubes close to inferior and superior limits. In photos you can see example of data. For tubes matched by curves or by Ip and Gm please see our other listings. The tubes passed all quality checks - vacuum, shorts, leakage, heater current etc. The tubes passed all quality tests (vacuum, leaks, shorts etc.), measured with Roetest, curves analyzed, the buyer will get all data, actual datasheet – test protocol, for each tube. Tested with Roetest V10, "the Rolls Royce of tube testers" [emissionlab quote], a wonderful german professional system for testing tubes, it shows everything about a tube. Those who use tubes are more familiar with terms like bias, gain (µ), plate current, slope/transconductance, and maybe someone is wondering what the term „D of plate” in the measured data means. Its value in itself is not so important but it is useful to calculate the other parameters taking into account Barkhausen's tubular formula S x D x Ri = 1 (slope * penetration * internal resistance=1), where D is –dUg/dUa at Ia=const. Barkhausen vas a german physicist, he was “the guru” of tubes, his theory and formulas guided the entire period of electronic tubes. Please allow for the following shipping times: EU countries: 5-8 business days, on rare occasions a few days more USA: 10-15 business days, on rare occasions more South East Asia (Japan, Singapore, S. Korea, Hong Kong, Taiwan etc) 10 business days, on rare occasions more India, China, Russia, Kazakhstan, Pakistan, Indonesia, Malaysia, Thailand, Australia, South Africa etc: at least 15 business days, but frequently around 25 business days Please note that shipping cost is calculated at average. If you have any objections please contact me for a specific quotation.