Philips

Philips ECC81 12AT7 Foil D-getter Matched Pair - Heerlen 1955 TK1 - Same Code

Name: Philips ECC81 12AT7 Foil D-getter Matched Pair - Heerlen 1955 TK1 - Same Code
Brand: Philips
SKU: 266851141766
Price: 133.0 USD
Availability: OutOfStock

Philips ECC81 12AT7 Foil D-getter Matched Pair - Heerlen 1955 TK1 - Same Code

$133.00 USD

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Product Summary

The "textbook Heerlen sound" has been referenced in several Soundlumia listings of Amperex Holland 12AT7/ECC81 tubes, and many tube enthusiasts asked what that all means. So this is the answer: the late 1950s and very early 1960s tone, the beginning of over a decade's excellence in sound, the classic tonal template for all the great (and greater) Amperex/Philips/Valvo/Miniwatt tubes to be made in the years to come, the timeless Philips radio tone that many of us grew up listening to.

Sound Characteristics

The most distinctive sound feature of the Heerlen ECC81's is the transparent, natural and expansive midrange presentation, with a slight touch of warmth that illuminates your music. Every piece of music you play through these tubes sounds like from a vinyl record, whether your sound source is phono or not. The sound stage is spacious, deep and structured. Bass is incredibly deep but well controlled and feels as accurate as on the high end German ECC83's (Siemens, Telefunken, Valvo etc.) Thanks to the very rare foil d-getter on this pair, you get with fast response (as in the solid-state fast), overwhelming detail in sound and the realistic bass.

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): 4.06/3.24 mA/V - 74%/59% (100% = 5.50 mA/V)

Measured plate current(IA): 7.63/6.332 mA - 76%/63% (100% = 10 mA)

Tube 2:

Measured transconductance(GM): 4.11/3.25 mA/V - 75%/59% (100% = 5.50 mA/V)

Measured plate current(IA): 7.142/6.25 mA - 71%/62% (100% = 10 mA)

NO shorts, leakage or gas. NO noise or microphonics.

Curve trace is also included in the original RoeTest report.

Appearance & cosmetic condition

Besides the world-class sound characteristics, we still treasure this pair for its near pristine cosmetic condition given the tubes' age - nearly 100% of the paint is still intact on both tubes, and the Heerlen date codes are perfectly visible on both tubes:

Tk1 ⊿5J (Tk = ECC81, ⊿ = Heerlen, Holland, 5 = 1955, J = October)

Tk1 ⊿5I (Tk = ECC81, ⊿ = Heerlen, Holland, 5 = 1955, I = September)

Packaging

NEW white boxes.