Siemens Products Tour
Siemens & Halske was a quality German tube manufacturer from way back. They made an excellent 12 volt series of tubes (12AX7, etc). However those of us that go back 20 or 30 years with the 6DJ8 know that when it comes to frame grid tubes (6DJ8, 6922, 7308), Siemens really shines and has always been one of the very best. This is not surprising, as that part of the world (Germany & Holland) produces some of the world's finest machinists. And that is what you need because the 6DJ8 tube uses a very tightly strung tungsten grid wire that is 0.00029 inches in diameter! This is the smallest tungsten wire that can be drawn consistently and is not even visible to the eye without a close look! But this was not new to Siemens as they had been experimenting and producing a tube, which was a predecessor to the frame grid back in 1926, it was the OCK tube, developed for undersea cable amplifiers. Well, what does all this experience and intrinsic skill give your music? A very quiet, smooth and neutral tube that has as much or more mid and high end detail as anything else ever made. The Siemens are particularly good at being free from noise & mic. and staying that way for a good long time. (I am talking about early production, not the mid- and late- 70s stuff) The only problem I have ever heard voiced about a Siemens 6-volt tubes would be in a system that was already too far on the light side and really needed a richer tube.