Which 6SN7SE should I get?

It has come to attention that some shoppers are confused by the different ‘6SN7SE’ tubes available on the market now.

We here clarify as below:

What we offer is called ‘Treasure Globe 6SN7-SE’ (GF Limited Special Edition).

GF stands for ‘Grant Fidelity’.

Globe is the shape of the glass enclosure as most 6SN7 tubes are either straight bottle, or mini 300B shaped with a shoulder.

SE stands for Special Edition, as this model was custom made for us based on the best possible design feature and electronic specs for single ended triode (SET) tube amplification.

We contracted tube factory made the special batch for us. We screen all tubes by our QC standards, not factory’s QC, and then further graded them to ‘low noise Grade A’ and ‘driver grade B’. For those not passing these two grades by our QC standard (about 53%), we instructed factory to destroy them (this we cannot verify if done or not, or these sub-grade tubes flew out of back door to some other vendors).

All our ‘Treasure Globe 6SN7-SE’ (GF Limited special Edition) tubes have front Chinese calligraphic logo of ‘Treasure’, plus a back printed line of ‘GF Special Edition’. They are only sold from THIS website, not any other vendors directly or indirectly. Whoever claim they sourced the tubes from us and of same quality, it’s NOT true.

Psvane itself has launched 6SN7SE (clear glass globe shape, with white ceramic base), and 6SN7BE (blue glass globe shape, with white ceramic base). Both are offered under ‘HIFI series’ as varieties to entry to mid level 6SN7. These are NOT the same tube as our ‘Treasure Globe 6SN7-SE’ (GF Limited special Edition). Other tube factories in China may also offer globe shaped 6SN7 and call it ‘6SN7SE’ – they are NOT the same as our offering and have no relations to us either.

Hope the above clarifies the confusion around this SE model, and allow all shoppers to shop wisely with adequate information.

Happy Listening.

Grant Fidelity

Another tube factory is born…LIINLAI with many new tubes!

Check out our new additions: Tubes by LINLAI – a new tube factory from China!

Who is LINLAI? (click on link to read more)

What tube they make?

  • Flagship: Elite E-series
  • Replica – WE Series
  • Innovation & Budgetable – DG Series

845, 805, 300B, 101D now in stock! Others coming soon.

Promo Offer! LINLAI factory is sponsoring us for ‘Feedback Bonus’ – valued at $50 per pair for first 30 pairs of all Elite and DG models combined, from now till Sept 30th, 2020. Conditions to receive the ‘Feedback Bonus”:

  • Must place order through THIS website, not other online vendors
  • Order completed by September 30th, 2020
  • Minimum order amount $499 for LINLAI E-series and DG-Series tubes only, not WE-series.
  • Submit a minimum 200 words ‘comparison’ feedback by email to what tubes you previously use – focus on sonic difference rather than putting down other brands. We are not buying good reviews – we want to hear from audiophiles how LINLAI sound in comparison to other tubes you have used.
  • First come first served. Bonus offer will end when 30 pairs reached.

What you should know about high voltage tubes such as 845, 211 and 805

Some precautions about using high voltage power tubes:

Unlike other vacuum tubes such as KT88 or EL34, which typically run at 450V plate voltage, high voltage power tubes such as 845, 805 and 211 run at plate voltage 900V or even higher depending on your amp design. Due to the high voltage in the circuit, biasing an 845 / 805 or 211 amp improperly may expose you to lethal high voltage causing instant death. If you haven’t owned any tube before, we recommend you to be cautious when starting with a 845 /805/211 tube amps and get yourself comfortable with maintaining such high voltage tube amps.

Always bias your amplifier by strictly following your amp manufacturer’s instructions. Do not bias the plate current over suggested reading (usually in mA) in any case. This will cause tube overheat, tube failure, shorten tube life significantly and even burn out other parts inside your amp.

High voltage tube has maximum rating of plate heat dissipation. Do not run your amp at a plate current that could cause the tube plate turn red hot (it is a cherry-ish deep red glow in a dark room. Normal tube glow is more towards orange-ish). When you start using a new tube, try it first in a room with dark light so that you can observe the plate color closely. If the plate turns red hot, turn down your amp bias immediately until the plate no longer show overheat symptom. Bias the two channel’s plate current readings to the same safe level for both tubes. It’s not recommended to have two channels biased at different level.

Plate heat dissipation (measured in watts) = plate voltage (in Volt) x plate current (in mA) / 1000

For example, if a tube amp has plate voltage of 960V on the 845 tube by design, and if the 845 tube has max plate heat dissipation rating of 75w, your maximum plate current bias reading should be 78mA. If the amp has plate voltage of 910V by design, your maximum plate current bias reading should be 82mA. It is not recommended run a tube constantly near its peak rating so ideally you should set your plate current bias at about 10-15% below the maximum. This will prolong your tube life and ensure a safe and long term enjoyment of your amp.

Although each tube amp has its designed plate voltage for tubes at a fixed input power voltage, a variation of more than 5% of your input power voltage may cause the plate voltage for tubes vary greatly (for example, swing from designed 910V to 950V or even higher). In such a case, your tube could be overheated and fail in a very short time. It’s strongly recommended to use a power conditioner properly designed for audio with your tube amp to reduce the possibility of such an accident and financial loss.

An excellent tube amp design along with poor selection of parts and poor production quality control could also cause your amp to overheat a tube and cause it fail prematurely. Always choose amplifiers made properly for your local voltage from a reputable reseller. In the past, we have seen many after-market modified Chinese tube amps which have been sold into North America with main transformers not designed for the right voltage, and cause not only inferior performance, but also tube failure or burning up components. Be very cautious when buying ‘cheap’ dual voltage tube amps from overseas.

Last but not least, never leave your tube amp unattended for extended period of time. Never leave a 845/805/211 high voltage tube amp on without anyone in the room.

We usually do not recommend people to chase so-called ‘high wattage output’ 845/211/805 amps. Some of these amps were designed to run output tubes at its marginal peak rating in order to squeeze a few extra watts – those watts you as a consumer may never actually need because most tube amps only sound excellent in their ‘sweet spot’ output ranges, that is – not too low and not too high. Allocating your funds to a pair of properly matched higher efficiency speakers to your 845/211/805 amps is a much much better bang for the buck, and it’s a much enjoyable musical experience too. Do NOT waste your money on chasing the last few watts by driving your tubes hard, instead focusing on get the BEST first few watts!

Due to the complicated feature of a tube amp’s design and user’s settings and maintenance vary greatly, tube manufacturer only warrant a vacuum tube for 90 days. If a tube has inherent manufacturer defect, it will show in the first 90 days of normal use and it will be covered by warranty. Improper usage including amp voltage not properly matched to your local power voltage, using tubes in an amp not suitable for the specific tube or set bias too high or too low, input power spikes etc will result in tube failure prematurely – such incidence will not be covered by tube manufacturer’s warranty.

6CA7-Z / KT88-Z or WE 6CA7Plus / WE KT88Plus – which one?

Answer to an inquiry from Germany – related to Unison Simply Italy:

6CA7-Z and KT88-Z were released over 10 years ago to the market as the very first high end upgrade tubes. But over years, the factory’s lack of quality screening has flooded market with mixed quality. We (Grant Fidelity) no longer carry them as the ‘selection’ cost is simply too high and performance varies too much. 


WE Plus series is the latest release before Shuguang factory went into relocation and ceased production in 2020 till further notice. From our own evaluation, the sound of this series is much better than previous Z-series (yes people do hear lots of good things about Z-series as they have been on market for 12 years with certainly more users). We selected through the entire factory stock and acquired less than 10 quads which meet our quality standard. We won’t hesitate to recommend them, simply just by the excellent test results we have seen on those we picked.


For your amp – i see the manufacturer website showing it uses EL34. It can be replaced with WE6CA7Plus no problem. I don’t see mentioning this amp can use KT88 – so please make sure your amp indeed can use KT88. If so, WEKT88Plus can be used. 


In general, KT88 gives more bass low frequency but resolution for midrange and high frequency isn’t as good as 6CA7. You can have to decide what is more important to your listening and choose accordingly. 


Hope this helps. 

[Best of the Best] from ENTIRE factory stock of WE KT88 Plus / WE 6CA7 Plus – Very limited availability

By popular demand by our loyal customers to experience different varieties of KT88 / EL34 types of tubes, we have sourced the ‘best of best’ possible quality of WE KT88 / 6CA7 Plus from the Shuguang tube factory’s entire current stock for the ‘most demanding and quality conscious audiophiles’. VERY LIMITED QUANTITY on both models. Get yours before it is sold out…. (Shuguang factory has ceased production due to factory re-location and a recent fire. Production resume time is unknown at this moment so we are not sure when we will be able to source these models again… so don’t wait too long till stock sold out.)

Who is LINLAI Tubes?

LINLAI is a brand name, and it is a phrase taken from an ancient Chinese poem praising ‘the Beauty of Music’.

LINLAI is a trademark belong to a NEW tube factory in China – formed by a team of engineers who exit Psvane in 2019. This story script sounds like an ‘encore’ of how Psvane was formed a decade ago, when a team of engineers exit the state-owned Shuguang tube factory.

What tubes does LINLAI produce?

As a newly established tube factory but certainly formed by a group of veteran professionals including an ex-VP Production from Psvane tube factory, LINLAI started its product line with triode tubes other than small signal tubes or other power tubes. Triode tubes include 300B, 2A3, 211, 845, 805 and they also produce 274B rectifier tubes.

It is said LINLAI will start producing popular power tubes such as EL34/6CA7 and KT88/6550 at late 2020. Higher power output tubes such as KT120 and KT150 will only be considered for production when the factory has fully commissioned the process to perfection for KT88 type first.

Should you purchase LINLAI Tubes?

There have been many many same models of triode tubes (such as 300B, 845 etc) pumped out by the two major tube factories from China, Shuguang and Psvane, in the past 10 years, under different OEM brands and series. Now comes the 3rd high end tube factory LINLAI. So how do you choose among them?

Psvane is derived from Shuguang. LINLAI is a derived from Psvane. It is no surprise to see some similarities across their tube offerings, since the engineers are hopping from one employer to another. Each brand has its own core offering:

Shuguang – more dominant in entry level stock tubes for tube amp manufacturers. We found the quality control on high end Shuguang tubes is a hit and miss. If you go with this brand, be sure to purchase from a reputable vendor who does their own screening and stand firmly behind their warranty. You may notice that we at Grant Fidelity are now gradually discontinuing Shuguang tubes – mainly due to the Shuguang factory warranty terms are not as good as Psvane has offered, and we see much higher reject rates for Shuguang tubes than from Psvane tubes. It would be ideal for Shuguang as a manufacturer to tighten its quality control and do not let all quality level of tubes out of factory door.

Psvane – with a decade of experience in making primarily high end tubes, Psvane and Grant Fidelity have formed a solid relationship for us to pay a price premium in order to have “first dip to their new production inventory”, which in turn greatly reduce our reject rates from each Psvane factory shipment. Psvane warranty policy so far has been solid – by promptly replacing tubes within agreed warranty terms. If we rate Shuguang warranty from 1-10 scale, it is a 6 or 7 max in our opinion. But Psvane can score to 9 out of 10 based on our experience.

Linlai – As a new comer, Linlai is also focusing on upgrade tube market, by introducing two innovative series – one with “Moly plate”, and the other with “Overhung filament” structure. Sonic feedback from early adopters in Asian market has been very positive, let alone its sharper pricing compared to Psvane. Linlai has also offered “as good warranty as Psvane, in some case even better”. Even though we have limited first hand experience on warranty claim yet (since we literally haven’t had any Linlai tube failure yet!), our communication and commitment received from Linlai has been top notch. We would say that consumers can purchase Linlai tubes with the same confidence as with Psvane branded tubes.

We will be working with professional reviewers in the next while to have more unbiased reviews done on the Linlai tubes. Please keep come back to our website, or google audio forums to see early adopter audiophiles’ listening impression.

The 100% Identical WE Replica series by LINLAI:

LINLAI’s WE-series offering are identical to Psvane WE series. There is NO difference. They are 100%, 1:1 identical, visually and electronically.

It is a ‘1:1 duplicate’ of the ‘Psvane WE845 replica’, by LINLAI Tubes, made according to the exact same blueprint, with exactly the same materials from the same suppliers as before. NOTHING IS CHANGED, except the brand printed on the glass. We were told that Linlai holds the design right of these WE replica tubes, as the designer of the series have now joined Linlai.

As a newer business, LINLAI is pursuing market shares aggressively, so they priced some of the WE model (such as 845 and 300B) lower than what Psvane previously offered. The end result is positive and favorable to consumers: same WE tubes are offered at lower price and more audiophiles now can afford to experience the Western Electric replica sound without breaking the bank!

Other less popular WE models such as 101D, 274B etc, remain similarly priced as Psvane.

What will happen to Psvane WE series, then?

From impression we got from Psvane, they are shifting to focus more on their ultra high end new ACME series which has all the overlapping models with WE series. It appears Psvane doesn’t want to get into a direct competition with LINLAI on who makes a better WE replica tube. Once Psvane sells out their current WE stock, this WE-series may not be produced in Psvane factory in the future. We will update if this situation changes.

The competitive flagship Elite E-Series by LINLAI:

This Elite series is the proprietary design flagship series by LINLAI. It is positioned to compete with the Psvane ACME Supreme series and other European tube brand in the ultra high end upgrade tube market.

The listing page of each model under Elite E-series will have all details on their design features.

Since LINLAI is counting on this Elite series to make its foothold in the high end tubes industry, we can see from the final products that efforts were not spared in the production. Since it is positioned to compete with Psvane’s top ACME series, LINLAI Elite series has price set slightly lower than Psvane ACME.

Do they sound at least as good, or even better than the highly famed Psvane ACME series? We will know with more market feedback, as they are still very new to the market. However, because the design difference between the two, we feel it’s more fair to say they each will have their own advantages. For those with bigger budget, you may consider to take the ‘cost averaging method’, by acquiring both tubes under ACME and Elite series, and enjoy them both to your different music mood and style.

The ‘bread & butter’ DG series with ‘overhung filament’ by LINLAI:

Replicating identical WE series and competing with lower priced flagship models are not long term sustainable strategy for a business. So LINLAI has also set their focus to cannibalize the ‘quality + price’ hunger mid-price tube market.

LINLAI spent significant amount of efforts to overcome the technical difficulties in ‘overhung filament’ design and created the DG series. DG – in Chinese, means ‘overhung filament’.

Among tube manufacturers and audiophiles it appears to have a consensus that: A metal plate tube by default will sound more dynamic and transparent than a graphite plate tube; and when same plate materials are used, a ‘overhung filament’ design by default will sound more delicate and refined than other filament design.

Overhung filament is extremely difficult to manufacture as a tiny discrepancy in spacing, fixture and material characteristics under extreme temperature can lead to more possible ‘failure’ in production. Overall, tube factory will face a much higher rate of ‘scrap’ even before a tube reaches the product finishing line. This leads to eventually higher overall production cost. Many tube factories deliberately stay away from this filament design.

845, 211 and 805-DG are made with graphite plate and overhung filament. As LINLAI counts on this series to be their future ‘bread & butter’ to take a solid market share in the upgrade tube market, these tubes are priced also very attractively below the $500 per pair mark and certainly worthwhile for audiophiles to explore the sonic benefits of this unique design.

The ‘Me Too’ TA-Series, T-Series, Z-series by LINLAI:

What else does LINLAI produce?

No surprise that they also make ‘very similar’ models offered by Shuguang tube factory – the black bottled triode tubes under TA-series, T-series and Z-Series.

It is understandable that in order to keep the new tube factory to optimal production capacity, LINLAI have to keep the full time workers busy for enough hours per day, and hope to capture as many market shares as they can.

Shuguang being a state owned factory, IMHO, is not well managed in terms of production quality and marketing in recent years. We certainly can understand the reason: state owned corporate CEO’s are nominated by upper management, not necessarily by market performance. Because of this ‘not-business-first, not-market-driven’ management mentality, we have found in the past years that warranty claim with Shuguang has been rated from inconvenient to very difficult, and frequency of claim has been much higher than what we experience with Psvane. We have gradually phased out from carrying Shuguang branded upgrade tubes – it is simply not economically possible for us, as a western business to honor warranty to the level we deem appropriate in the western world, to make it viable for business. We as commercial tube vendors selling in large quantity of tubes must rely on ‘statistically satisfactory’ warranty practices, not on ‘maybe I am lucky and Paypal will back me up’ as consumers often hope for.

We hope by reading this post, you now have a good understanding of what LINLAI Tubes is about and if you, as a consumer, can find a suitable ‘performance + price’ tube offering from this NEW TUBE BRAND. We think it is certainly worth a try! As always, Grant Fidelity will honor warranty as with any other tubes we carry.

Last words: What about ‘NATURE SOUND’ tubes?

The very early batch of LINLAI tubes were printed with a brand called ‘NATURE SOUND’. Later on it turned out that the trademark had been used and registered by an un-related business, so it cannot be legally used on any commercial audio related product anymore.

We do NOT have stock of any ‘NATURE SOUND’ tubes. Early batches from a new tube factory could often be of uneven quality while the production lines are being commissioned to perfection. We have waited till quality stabilized to carry the current ‘tubes by LINLAI’.