Sylvania JHS 12at7 Gray Plates 2 mica

1 Star2 Stars3 Stars4 Stars5 Stars (4 votes, average: 5.00 out of 5)
Loading...

2 thoughts on “Sylvania JHS 12at7 Gray Plates 2 mica

  1. WOW!!! I just received these tubes from Germany. Got them on Ebay for $16 for 3. Almost filed them away with the rest of the similar tubes until I noticed that these tubes have only 2 mica and… check out the heater connection on the top of the second mica. I haven’t seen anything like that before. but wait, it had plates that are very unusual for 12at7 – not wing shaped. So I started to so some research. Couldn’t find anything. Nothing on ebay, nothing on tubemongerlib.com. The closest one in plate structure was Telefunken ECC801S. At first I thought that these are just re-branded, but it clearly states made in USA and Sylvania didn’t do re-branding of other tubes under its own name. So why the heck did I spend all this time digging around the net try to find information? Because I wanted to buy more of these! These are not just good. These are incredible. The tonal delicacy that the tube could produce was absolutely out of this world. I thought that I had too much wine, so I plugged Telefunken 12at7 and Amperex 12at7. Telefunkens were not even close to the amount of details this Sylvania was able to produce. Amperex was very close, but a tiny bit of speed was missing. How do they compare to the JHS 12at7 triple mica? Triple mica is great, but these are phenomenal.

  2. Finally, I had the opportunity to try this quite rare tube (in a preamp section) since i found one on ebay for $14. To express my first impressions I can use only two words – fast and solid! I have never heard fastest 12AT7 tube than this one, at the same time it is very musical and you cannot hear any sort of congestion or smearing throughout the whole frequency range. It is also the 12AT7 with the most upfront sound with very deep and solid bass and completely natural midrange.

    The treble extremes are special story, it rivals Sylvania JHS black plates 3 mica in that region and it has even beter 3D effect. I found my listening room simply overwhelmed with tons of details and so far unheard sounds…
    Warmth is not its first name but this is the price paid for speed and magical treble delicacy. Personally, it creates a bit more bass output in my system so I decided to revert to RT 12AT7 for its more relaxed and bass-balanced sound. Nevertheless, with some other output tubes no doubt I`ll use it again, that kind of sound could not be forgotten so easily! HIGHLY RECOMMENDED with careful system matching.

Leave a Reply