Linlai E 6sn7 tubes

@weebeesdad , did the Chinese vendor list them as Grant Fidelity "top 10% Ultra Low Noise?" Does the tube have PVT stamped on the glass?

My take after reading the GF website is the Ultra Low Noise is a replacement for their previously offered tube, not just tighter specs on an existing tube. They mention a different tube structure.

@lowrider57 The vendor does not list them as a Grant Fidelity tube. The pictures shown are not detailed enough to show any markings on the glass. It does show a "plaque" on which is engraved "Linlai Tube E-6sn7 - 01512". When I receive the tube I will look for "PVT" stamped on the glass. I was under the impression that GF's low noise designation was just a tighter spec and not a different structure tube, but I could be mistaken.

Thanks for your reply.

@weebeesdad , my first impression was that these tubes were graded higher due to tigher specs, the same way Kevin at Upscale offers his tubes. The choice of tube listed is "Top 10% Cryod" or "QC Pass grade." You may be right, that they're not a new tube. They're a higher grade. 

A rating called QC Pass grade doesn't inspire much confidence in the quality of this tube. 

@lowrider57 The Linlai website does not grade their tubes, one could assume that their buyers should consider their purchase as having passed a Linlai quality control standard. That leaves me with my original concern that the tube I will be receiving may be of a lower quality even if it is a genuine Linlai tube, perhaps a Linlai "reject"? At this point I just have to wait until I receive it and listen to it, which, other than its reliability, will be the ultimate test regardless.

I have the Shuguang Treasure 6SN7s on my Don Sachs preamp. Don says in his website that these simply walk away from the holy grail NOS tubes. That's quite a statement.

Obviously this is not the case with all NOS tubes...as a lot of the culture that made these tubes is gone forever.

All of our customers that have installed some of these boutique tubes say the same thing- that the Psvane, TJMusic and so on have all the best qualities of the best NOS tubes without the weaknesses.

I can confirm that the Shugang plant that made the garden variety of 6SN7 burned down about 2 1/2 years ago. Also, FWIW every example we've seen of the Sophia 6SN7 has been weak. We've only seen them installed in customer equipment, and so far when asked no-one has said they were in the equipment for more than 6 months. So we think this tube has a defect causing a short lifespan; NOS tubes will last for years in our stuff.

So far the Linlai tube seems to be a better part. I'm hoping it has a good lifespan as I mentioned earlier; if this is the case the tube is a steal at its price.