Newb Tube question
This may help. It is for NOS tubes https://www.gearslutz.com/board/attachments/low-end-theory/244587d1310547014-art-pro-mpa-ii-big-tube-discussion-thread-12ax7_guide.gif |
NOS tubes are vintage tubes which sound better than new production which mostly come from Russia, although these tubes have been improving over the past few years. The Project website states that the Tube Box S2 phono stage uses ECC83 tubes which is the European designation for 12AX7 tubes. These are widely used in audio components. The following website provides good info on the different manufacturers and a description of how the tubes sound. Lower down on the page are the tubes for sale. There are many versions of 12AX7’s which include different plate types and internal tooling. http://www.audiotubes.com/12ax7.htm |
Tube rolling is never ending quest, you’d better look and read an Tube Asylum site. You tube (ECC83 /12AX7) is slightly different from mine (ECC81 /12AT7), i ended up with NOS Sylvania Gold Brand (Gold Pins), Matsushita, military Telefunken are the most expensive... Sylvania was the best value for me. You can always look for RCA Avoid Chinese tubes, in general Russian military grade are not bad if they are very cheap, but you’d better look for NOS from the 50s 60s 70s. If (ECC81 /12AT7) are compatible for your phono pre you can ask me, i have some NOS |
With vintage small-signal tubes, long plate variants are usually considered more desirable. Long plates and short plates are not specific to a manufacturer, but they are generally used in reference to 12ax7 or 12au7 type tubes. "Long" is generally around 19 mm, and "short" about 16 - 17 mm. In most cases, a manufacturer produced long plates in their early-year runs of that type, and then later switched to exclusively short plates (late 1950s - 60s). In general, earlier vintages from any given manufacturer contain features that are considered more desirable (but it can be hard to decouple this from the fact that earlier vintages themselves are almost ALWAYS more desirable in vintage tubes!) - other examples of this include specific kind of getters (square, "D", or double halo getters versus later single halo getters), black plates vs. grey plates, triple micas vs. double micas, pinched waists vs. straight tubes, larger and prettier getter flash patches (e.g. Sylvania "chrome dome" 6sn7), etc. The "smooth plates" are a pretty unique feature and pretty much always refer to the Telefunken 12ax7/12au7 tubes. Those are excellent tubes. Ei (Yugolsavia) later bought the old Telefunken tooling and made smooth plate tubes for some years - these are good tubes too, but perhaps not as good as the original Teles. With new tubes you can find tall and short plate variants of 12ax7/12au7. If I were to generalize (though probably badly badly), the tall plates tend to give a sweeter sound but the short plates could be less microphonic (less to rattle around). |
