One thought on “Raytheon 9au7 short black plates”

1. I was going through a pile of tubes that I got recently and found a few tubes that I didn’t play around with before 9au7. This tube is 9v version of 12au7, but unlike 12au7 it has the same pin out as 6dj8 or 6CG7, etc. The tube had black plates, which is good in my book and it was branded RCA. The plates where flat short plates and I don’t know of any RCA 12au7 that had this kind of plates, so there it went into my amp. A bit more investigation later uncovered that the tube is actually made by Raytheon. It took some time to warm up since my amp is wired for 6v and this tube needs 9v heater, but as I wrote before, that’s not too far apart. HOLLY F…………

   I absolutely couldn’t believe the sound that was coming from the tube!!! It was the most musical/liquid tube that I’ve tried. You have to listen to it to understand what it is. I just couldn’t stop listening. Every singer was opening a bit more of their sole through the tube. In addition to that, bass as very strong and tight and details were absolutely delicious.
   I put this tube for a test and 3 different amps and every time the results were the same – absolute liquidity!!!

   I even went ahead and compared this tube in blind test with Siemens E88CC and that little Raytheon won – in vocals!!!!!!!!!!!!!!!!!!!!!!! $3 tube won against $100 tube.

   I can’t believe that this kind of tube could have escaped attracting a lot of attention. The only explanation is that the tube is very rare and the unusual heater voltage made it obscure.

   So the next thing that I did I found a pair of these tubes on Ebay (the only pair that they had of the tubes) and bought it for $6 shipped!!!!! Nice.
   So if you have a system that takes 6CG7, 6DJ8, 6AQ8 try to find the tube – you might be VERY PLEASANTLY SURPRISED. HIGHLY RECOMMENDED.

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