That is a very broad statement, cheap Chinese tubes are just that, cheap and in most cases you get what you pay for but I quit chasing NOS tubes for my all tube system a long time ago, if Psvane makes a premium tube for what ever my need is I buy, install and move on.
Due to my history of importing Chinese audio components, several years ago, a number of people approached me in regard to doing the same with vacuum tubes.
Over the course of a couple of years, I sold a lot of Shuguang and Psvane tubes. While I found the ruggedness encouraging, the level of sonics surprised me most. In my experience, outside of today’s more exotic production, Chinese vacuum tubes represent the best sounding, most reliable in current production.
The base Shuguang 12AX7B, 2A3B / 2A3C, 300B, 211, 845, EL34B, EL84, and KT88 cost less than pretty much anything else out there, provide good sound, and the best reliability currently available. Yes, there were some tube types that did not hold up in the field, and after discovering that, I stayed away from them.
The Shuguang 12AX7B aka Silver Dragon bests most American and European offering from the golden age. I didn’t believe it, and it still seems implausible. But they blew the Mullard 12AX7 right out of my Jadis. I hosted a tube shoot out with 20+ audiophiles, some of which post here on Audiogon. We ended up breaking things up into three rounds of elimination. The Shuguangs surprisingly bounced such highly regarded tubes as the Telefunken smooth plate and Mullard, to make it to the last round to place in the top 3, along with the Sylvania triple mica black plate 5751 and Telefunken ribbed plate.
I’m not a big a fan of the sonics of the Shuguang 6SN7 and 5AR4, but have still found them quite reliable. I love the JJ 5AR4 in comparison, sonically, and that’s what I use in my amps as sound is my highest priority. But the JJ 5AR4 disappoint me as they just fail / arc over too easily. I will say the ugly and old looking NOS metal base Shuguang 6SN7 variant (labelled 6N8P) sound pretty good.
Because of personal experience, and learning the hard way, no one’s more skeptical of Chinese high-end audio components and the companies that produce or sell them as I am. But the vacuum tubes come from a different industry; one I have gained far more confidence in.
I recently got a pair of the Treasure C181's for my Don Sachs custom octal-tube based preamp and they are an improvement over all the 50's and 60's NOS 6SL7's I have been using. They are ultra detailed against a black background. I don't know about their longevity, but they are by far the best Chinese tubes I have ever heard, clearly bettering the fabulous NOS tubes I had been using and loving. I bought a quad of them for spare. Don tried them in his own preamp and his experience mirrors mine. Check around on eBay for the best prices on them.
I have several drawers, (hundreds and hundreds of tubes) full of tubes. Both NOS and new production. I have found the new production Shuguang and Psvane to be as good, if not sometimes better, (depends on the circuit) than any of my NOS tubes from Mullard, Amperex, Telefunken, Siemens, etc.
So saying "all" of the Chinese tubes are bad, it just wrong.
One has to be careful with broad brush statements when their are so many variables at play. I use a mix of NOS & Chinese tubes in my systems with excellent success. The NOS 845's & 300B's were just a little too expensive for my budget. I used the Shuguang ,Nature series & 300B Treasure Series in my Cary 211 amps & I am very happy with the sound as well as the reliability. I had the 300B's cryo treated which kicked their performance up another notch.
That is a totally inaccurate statement. Vac , and many others have been using dependable matched tubes for years Shugaung has been making tubes since 1958. They have had old RCA and Tungsol original machines in there from way back and have made new machines similar. Their El34, Kt88 Kt120 power tubes all very dependable . And small signal tubes a lot direct American copies .Old 60s50s tubes tubes better for various reasons mainly a bit better materials and much closer inspection per 100, hoot 1,000s if you want top tubes the a Black treasures are very good quality and highly musical. They are a bit $$ pricy but are superior for power tubes no Russion tube is better. And if you buy from them on eBay you get a full 12 month warranty . You will not top that.
We used to use the Russian 6SN7s. They really didn't perform well and were unreliable. About 1998 or so we switched to Chinese 6SN7s and they have been treating us quite well. They are not the best sounding 6SN7, but they are not bad. They are copies of the JAN Phillips 6SN7 and not surprisingly sound about the same.
I find that the Russian power tubes on the other hand work pretty well. The Chinese power tubes don't seem to do so well.
We use Chinese 12AT7s in our phono sections since its hard to find 12AT7s that are quiet and non-microphonic- terrible luck in that regard with the Russian tubes! But a box of 100 of the Chinese tubes will have only about 10 rejects, which is better than the about 90% reject of the Russian variety! Most of the NOS tubes these days are too noisy.
So my impression is that the Chinese do pretty good on the small signal tubes and not so good with the power tubes.
Regarding the boutique tubes: Psvane, Sophia and TJ Music:
This applies only to the 6SN7s so far, but customer feedback on these tubes is that they combine the best qualities of the NOS varieties without their weaknesses! pretty potent comments! No reliability issues have been reported so far (the last 2-3 years or so). Again, these comments apply only to the 6SN7 (there are no boutique 6AS7Gs as yet, and the only other tubes we use are the 12AT7 and 12AU7).
Chinese tubes are quite satisfying in my opinion. Not only more affordable, but also reliable and sonically good. I'm using the KT88 from Shuguang and compared to other brands that I tried on the same amplifier, the results (sonically) are not much different - especially when looking at the price difference. On other hand, I opted to swap the pre-amplification valves (12AU7 and 12AX7) from Shuguang to Genalex Gold Lion. Not because the Chinese ones were bad, but I truly heard a nice improvement in sound quality for a small amount of money.