This setup truly reveals even the minutest details. Long 'D' Getter, early 50s, White Lettering: The tone was excellent and even with very good articulation. U-Getter with Foil Crossbar, White Lettering, early '50's, ULTRA-RARE: Absolutely wonderful sound! The Raytheon sound has a hint of darkness added to the detail.SIEMENS E188CC / 7308 1970's Made at Munich factory of Siemens & Halske in the 1970's.
Dating siemans 12ax7
In Belgium they made chicken food from used engine oil.
Or how about this story: In 2014 in China, several managers of a milk factory were convicted to death, for faking baby from oil, water and chemicals.
Pair Siemens E188CC Silver Shield NOS NIB Emission Matched: 110/105 % 110/115% 11.
Matched Pair Telefunken E88CC NOS NIB Emission 100/95% 105/100% 12.
Some of the following reviews are courtesy of Watford Valves in the U. The most up to date test data and reports will be found in the Tube primer documents elsewhere on this website.
My reviews are more technical in nature and a bit more "black and white", so these reviews by Watford Valves are really nice when you want some "tone" viewpoints. There is a link at the end of the reviews to their website.
One of the features of that amplifier is that many of the audio path internal components are also old stock and hand selected including OIP (oil-in-paper) capacitors, military quality hardened switches, and hand built transformers. The sound was so similar in all varieties that it is not possible to break them out individually.
This pre-amp feeds an E80L amplifier driving a pair of Teresonic Lowther-based speakers. As a class of tubes, the black plate Raytheon are truly superb--equal to the best of the RCA.
A little bit should be said about the equipment used.
The soon-to-be-released custom phono/line stage amplifier from Old Stock Audio has phenomenal articulation and uniquely reveals the subtleties of the tubes. There are seven different styles of 1950's and early 1960's Raytheon 12AX7 & 7025 that we were able to categorize.
If you have done any tube rolling, you know from experience that the 12AX7 has more effect on amplifier sound than the following 12AU7 or any other low/medium gain stage.