12AX7 ( ECC83 ) TELEFUNKEN Smooth Plates Diamond Bottom Matched Pair Tubes Made in Western Germany '60s
Sound Description:
The 12AX7 TELEFUNKEN , in this sought-after 1960s version with Smooth Plates , Diamond <> Bottom , represents one of the highest standards of European tube production.
Crafted at the historic Ulm factory, this select pair combines refined musicality , low noise and impeccable tonal coherence , making it an ideal choice for audiophile applications, recording studios and reference hi-fi equipment.
Bass : Fast, dry, and defined. The low end is tight and articulate, without artificial bloat. It provides a clean, solid foundation, perfect for systems that prioritize precision and control.
Mids : Transparent, fluid, and three-dimensional. Voices emerge with naturalness and presence, while acoustic instruments are reproduced with balance and realism. The Telefunken midrange is known for its elegance and ability to reveal subtleties without overemphasis.
Highs : Refined, detailed, and never fatiguing. The upper range is bright but free of harshness, with a natural openness that adds air and spaciousness to the scene without becoming intrusive.
Dynamics : controlled, precise, and progressive. The response to microdetails is extraordinary, with a smooth and coherent rendition of the most complex excursions. The tube maintains composure even in the presence of fast passages or recordings rich in transients.
Soundstage : Wide, coherent, and well-layered. The stereo image is focused, with clear separation of sound planes and stable spatial reproduction, resulting in a believable and natural soundstage.
The 12AX7 TELEFUNKEN – Smooth Plates – Diamond Bottom – Made in Western Germany '60s is one of the most highly regarded tubes in the history of audio. Synonymous with German precision, tonal neutrality and legendary durability , it is the choice of choice for those seeking transparency, micro-detail and long-term consistency .
🎧 Use in Headphone Amplifiers and Hi-Fi Driver Stages
Perfect for high-resolution tube preamps, DACs with tube analog stages, OTLs, or reference headphone amplifiers. Particularly suitable for use with models such as the Focal Clear , ZMF Atrium , Sennheiser HD800S , or Hifiman Arya , for a neutral yet engaging performance with excellent headroom and microdynamics.
🎸 Use in Guitar and Bass Amplifiers
In the preamp sections of Marshall , Hiwatt , or Fender Custom Shop amplifiers, the TELEFUNKEN 12AX7 guarantees a clean, dynamic, and noise-free response, ideal for both studio recording and live performance where clarity and definition are essential. The attack is prompt but not aggressive, with natural harmonics and well-controlled sustain.
🎯 Note for audiophiles and technicians
An absolute reference pair for those who want neutrality, definition and reliability , both in critical reproduction systems and in top-level audio systems.
Test Results
Tested on AMPLITREX AT-1000 Tube Tester
Voltage Test: Va = 250V, Vg = -2V
Average 100%: Gm = 1600 ; Ia = 1.2 mA
TEST RESULT: VERY STRONG
Valve 1 :
- Section 1 : Gm = 1500; Ia = 0.9 mA
- Section 2 : Gm = 1500; Ia = 1.0 mA
Valve 2 :
- Section 1 : Gm = 1500; Ia = 0.8 mA
- Section 2 : Gm = 1400; Ia = 0.7 mA
Additional Tests Performed:
- Microphonics: Low. Tested and approved for use in hi-fi and guitar amplifiers, including V1.
- Balance: The sections show a slight deviation in values; excellent for use in hi-fi and musical applications (guitar).
- Output Quality: Excellent – Very strong and stable output, no fluctuations.
- Short circuits and GAS: Absent.
Conditions:
- Condition: Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.
- Functionality: Fully functional.
- Aesthetic condition: Fair – Writing almost completely faded, with obvious signs of wear on the glass or feet. See photos for details.
- Manufacturing Code: None – Telefunken Made in Germany, identifiable by construction features. 1960s
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