Ah, I am sorry, I had forgotten I had promised to give some feedback on these valves.
The first thing to say is that there is no such thing as a better or best valve. They are just different and their suitability will be hugely dependant on the make of amp and also what other valves are used in the system.
I have been a fan of Psvane valves for quite a while having used the Psvane 2A3 HiFi series and the 12AU7-TII series in my Audio Innovations. I also used the 12AU7-TII to great effect in an Audio Innovations L2 Pre amp.
The need for the current search came about when the L2 preamp went and I got an Icon Audio L5 TX Signature edition preamp. It came with Shuguang CV181-Z valves.
All my comments therefore relate to these valves in the Icon Audio L5 but as I have used some of the valves in other kit I will try to bring that in as well.
Psvane CV181-TII series, the one with the bronze base. Straight off I have got to declare my love for this valve. In the L5 it gives me everything that I want out of my system, clear rhythmic and controlled bass, a sweet and musical mid range and detail in the upper ranges without becoming hard. This is the valve that I have kept in my preamp and it does everything that I want. Against that I have got to say that it is the most unreliable valve I have ever come across. I have bought it from the UK dealer, direct from china, direct from HK and also from other non UK dealers. What seems to happen is that after a while there might be a crackling noise through the speakers or a feint plopping noise. All of the sources, including China and HK, have replaced the valves without quibble but even so I think it can be an issue. All I can say is that I have tried to 'make do' with one of the other valves in my shoot out but in the end I couldn't do that and persevered until I got a perfect pair of the TII valves. It has been commented that there may be an issue with my amp causing the failures but the pair of CV181-TII valves that I have now have been fine for several months.My advice is to buy from known dealers who know that you are using the valve in a preamp and make sure you get the Premium or Export grade of valve. As an aside, I do have a set of 845 power amps which also use the 6SN7 as driver valves. I ultimately concluded that the CV181-TII was not my preferred driver in the 845 amps and instead chose the Shuguang CV181-Z. And thats what I mean about my comments having to be taken in the context of the system and other valves being used. I have yet to try the 845 amps with different First stage valves and that may change my thoughts on my preferred driver valve.
Psvane 12AU7-TII series. Icon Audio themselves sometimes use the 12AU7 valve in the L5 preamp i place of the 6SN7 (with a base adaptor obviously). The 12AU7-TII immediately sounds very similar to the CV181-TII. Very sweet and musical. Plenty of detail and very tuneful. But after extended listening there was just a nagging feeling that something was missing. Putting the CV181-TII valves back in solved that riddle. It was the fantastic bass and lower register of the CV181-TII that was missing. Although the 12AU7-TII was not my ultimate favoured valve in the T5, I do use 8 of them in my Second Audios and I must say I have not found anything to come anywhere near them in those amplifiers. It is clear a very fine valve and I recommend giving it a go.
Psvane 6SN7 HiFi Series. This is a fine valve. It has lots of detail but is perhaps has a (hardly noticeable) slight hardness to some of the upper register when in my system. To my mind the bass is not as satisfying as the CV181-TII but it is certainly there. This is a much cheaper valve than the CV181-TII and I would say it is very good value indeed for the price. I use the 2A3 HiFi Series in my Second Audios and like those very much indeed (although I have been trying the Psvane 2A3 TII meshplates in the Second Audios!!).
6SN7-SE from Grant Fidelity. The round one! This is the valve that started off this thread. It is certainly different in how it looks. It may not physically fit in all amps due to is width but luckily the Icon Audio L5 has plenty of space around and they slotted in a treat and look simply fantastic. I let this valve get run in for a couple of weeks because it was obvious that each day of use did improve the valve (I listen to my hi fi for about 9 hours a day because it is in my study where I do all of my architecture business work). This was clearly a very very fine valve and is of the highest quality in terms of sound. It has a lovely top and mid range which is very musical and has plenty of detail. The bass is there but to my ears was not as defined as the CV181-TII. I have a couple of tracks that I tend to listen to for this and they whilst they sounded very good with the 6SN7-SE, I preferred the CV181-TII. It was a close call though. The same was true for the upper register where I just preferred the CV181-TII. I could quite see that in another amplifier it could easily have gone the other way and the 6SN7-SE would have come out on top. I am sure that if you are tempted by the 6SN7-SE you will not be disappointed.
Shuguang CV181-Z. This is the valve which came in the L5 pre amp from the factory in Leicester. It is also a very fine valve. If I had not listened to any of the other valves then I am sure I would have been more than happy with this valve. It sounds great. However, to my ears and with my Power Amps it was sounding slightly muddy and unresolved in the bass. The overall effect though was very musical and often I would just sit back and enjoy the music and forget that I was trying to decide which valve I preferred (this also happened with the 6SN7-SE from Grant Fidelity). It only lost out to the acid test of putting the CV181-TII back in and when that 'Ah, Yes' feeling returned and the sound was once more just how I like it. And those words really sum up the whole test. I have selected the valve that I like because it makes the music that I like in my system. I mentioned above that I also have another system with a pair of 845 power amps. They are the MM845 MkII monos from Icon Audio and in which I have installed the Psvane WE845 valves. In these it was the Shuguang CV181-Z which came out on top compared to the CV181-TII. That's what I mean about there being no ultimate best valve. They are all just different.
The test system for all these was a Meridian 602 transport feeding a Chord Hugo DAC, Icon Audio L5 TX PreAmp, Audio Innovations Second Audios with Border Patrol Power Supplies, Living Voice Avatar Mk 2 speakers.
So, no answers but plenty to talk about. The only other thing to say in relation to Psvane valves (tubes but you guys know what I mean by valves) is that Rachel at Grant Fidelity is hugely knowledgeable and helpful. What is more they have the test kit to actually test valves after they have left the factory to ensure proper working and correct matching. I have an AVO VCM163 valve tester which I use to test all valves before I install them and I can assure you that may other so called matched pairs from other vendors are no such thing. Just because it is written on a 'test certificate' doesn't mean it is true.
