The most popular tube at the Soundlumia store, the audio tube that every serious audiophile wants to own, and perhaps the most legendary 6DJ8 tube on the planet. They fly off the shelves faster than we can restock, but here we are again: a very rare tightly matched pair of vintage 1960's Amperex Bugle Boy tubes made in Heerlen, Holland.
As far as the tonality, there isn't much to say except that who doesn't love Bugle Boy? These are the tubes that defined the house sound of Amperex Heerlen - very detailed, great bass definition, extensive midrange and the right amount of warmth. Instruments sound very natural and vocal reproduction is over the top. The sound stage is spacious and well structured, and instrument separation is the best you can get in this price range.
Professional Tube Testing
This set was tested and certified by RoeTest V11 Professional Tube Testing System with the following result:
Tube 1:
Measured transconductance(GM): 11.43/10.8 mA/V - 91%/86% (100% = 12.50 mA/V)
Measured plate current(IA): 11.812/11.16 mA - 79%/74% (100% = 15 mA)
Tube 2:
Measured transconductance(GM): 11.01/10.53 mA/V - 88%/84% (100% = 12.50 mA/V)
Measured plate current(IA): 12.99/11.385 mA - 87%/76% (100% = 15 mA)
Tube 3:
Measured transconductance(GM): 11.78/11.88 mA/V - 94%/95% (100% = 12.50 mA/V)
Measured plate current(IA): 14.197/14.167 mA - 95%/94% (100% = 15 mA)
NO shorts, leakage or gas. NO noise or microphonics.
Curve trace is also included in the original RoeTest report.
Appearance & cosmetic condition
We treasure this pair also because of the great cosmetic condition of both tubes - over 90% of the paint is intact and well preserved. The Heerlen factory date code etched on glass are perfectly visible on both tubes:
⊿6D1 (⊿ = Heerlen, 6 = 1966, D = April, 1 = Week 1 of the production month)
⊿6F3 (⊿ = Heerlen, 6 = 1966, F = June, 3 = Week 3 of the production month)
⊿6G2 (⊿ = Heerlen, 6 = 1966, G = July, 2 = Week 2 of the production month)
Packaging
NEW white tube boxes.
