Category: Purchase Guide
Linlai™ Global E-6SN7 on Feliks Euforia Headphone amp: from Germany
We have just received the feedback below from Greg K from Germany! Greg owns a ‘Feliks Euforia headphone amplifier’ which came with Psvane CV181-TII as driver tubes.
Read about his first impression after swapping to [Linlai™ Global] E-6SN7 for 26hrs – it might help those who wish to know how the E-6SN7 compared to Psvane tubes: (note: Linlai tubes full burn-in will take approximately 100hrs)
“I have now burned in the tubes for a good 26 hours so far.And on the Feliks Euforia, where the Psvane CV181-TII were before, a lot has happened. I listened with the Audeze Lcd 2 C headphones which are quite neutral. And relabelled 6080 Sylvania power tubes which also arrived on Saturday.
Compared to the Linlai Global E-6SN7, the Psvane are quite neutral in sound. I noticed this immediately after the exchange. This is no longer the case with the Lin Lai, they play much warmer.
The bass has increased considerably where before they were bloodless in direct comparison to the Psvane CV181-TII. The good thing about the Linlai is that the mids and highs are relatively unchanged compared to the Psvane CV181-TII. I didn’t notice any loss there, they seem to have gained a bit of sparkle.
They are also more accurate, closer to the music and go a bit deeper in the highs and a bit longer in the low end. Detail resolution is also very good, I like it better than the Psvane tubes.
Vocals are a bit more distant and more central than with the Psvane, or less voice accentuated, which I personally find better.
All in all, they are definitely worth the money and improve the sound of the Feliks Euforia dramatically. Before I was always getting disturbed by something, but that has gone since the first hour since the Linlai have been in. I don’t regret buying them. Much more the Psvane that you can book at Feliks.
It makes the Feliks neutral but cold, with the Linlai it’s just the opposite.
That was my first impression and I know they still need a little time to burn in. But they are getting better by the hour. Linlai has done a really good job. It also shows that after such a short time they are already so open and show the direction they are going in.
I am enthusiastic about the tubes. And I wanted to tell you that much about how good they are in the first hour.
With Kind regards
Greg”
Is the ‘Top 10% Best of Best Grade’ worth the money?
You may have noticed that our tube offerings are priced to different gradings – the best, also the most expensive, grade is ‘Top 10% Best of Best Grade’ at a price premium over typical ‘factory QC pass grade’.
Is the ‘Top 10% Best of Best Grade’ worth the money? What are you paying for the best grade?
Tubes, like most bulk commodities, are graded according to their tested parameters from lab equipment. Although vacuum tubes are industrial products, they are not cookie-cutting universal exactly the same when rolling off the production line. Consider tubes like premium coffee beans: They are all coffee beans, but not all the same coffee beans, and are not sold at all the same price.
Tubes are hand-made products. Many human factors play into the final quality and lifespan of tubes. Tubes are also live creatures – they are not in static fixed state through their lifespan – they change with the environment they work in, and change itself unexpectedly like a ‘living creature’.
An example on 300B tubes:
A factory QC pass grade 300B tube can have 60-70% of full emission but still considered ‘QC pass’ by a tube factory. Our selected ‘top 10% Best of Best grade’ will have minimum 85% up to 110% of full emission. The top grade will have approximately extra 30%-50% emission (in comparison terms between the two grades) to allow your tubes last much much longer.
Additional screening of our ‘Top 10% Best of Best Grade’ also have matched transconductance to the best possible range and no other imperfections in tested specs.
Why called top 10%? Because these tubes only take about 10% of the entire tube production batch. They are rare and hard to come by, when ALL parameters considered.
This comparison on 300B grading also applies on other tube models.
If budget isn’t an issue, we as buyers would personally go with top 10% best of best grade on these high end tubes, to make sure to get the best possible commodity for longest time enjoyment.
Hope this helps with your tube purchase selection!
Rachel @ Grant Fidelity
Can your 6SN7 replace my 6SN7GT, 6SN7GTA, 6SN7GTB?
We sometimes receive amp owners question about tube substitute related to 6SN7. Here is a short summary:
- GT stands for ‘Glass Tube’.
- GTA is an enhanced version of original GT version – to allow higher plate dissipation than the GT version.
- GTB is variant of GTA, with a heater warmer control to further enhance reliability when this tube was used in TVs.
- Very early 6SN7 tubes can handle max 300V. Today’s new production 6SN7 tubes can handle max 450V.
- In short, new production 6SN7 can replace your old 6SN7 without frying the tubes. But you should not use a NOS 6SN7 designed to handle 300V, into a modern circuit of 450V.
- All our listed 6SN7 tubes (no matter what suffix it has) can electronically replace 6SN7GT, 6SN7GTA, and 6SN7GTB.
- Do check dimension clearance to make sure the different glass bulb shape can fit into your amp space!
Happy tube rolling!
6SN7SE Globe Tube Tips – ‘You Raise Me Up’
Some amps have preamp 6SN7 tubes placed in a very tight real estate – i.e. two tubes are placed very closely to each other so the new high end 6SN7 with curved larger / wider glass enclosure cannot fit in side by side.
A customer from Europe recently told me his solution and I think it is worthwhile to share! That is – use a socket saver to raise one of the tubes up!
Just google ‘8 pin socket saver’ (not ‘socket adapter’ which may change pin layout connections) and make sure to purchase from a reputable audio parts vendor. Some lower quality socket saver can introduce current leakage to your circuit and cause unexpected noise issues.
Happy Listening!
Hear what the cable pro said about [Linlai™ Global] E-845….. ‘real keepers!’
Eric D. from France is an industry pro specialized in ultra high end cabling. His audition skills are professional and field proven, and here is what he said about after owning a pair of [Linlai™ Global] E-845 top grade tubes:
“The Linlai E-845s are very nicely built. You can tell by looking inside
the glass tube that they are manufactured with care. When brand new,
they performed nicely, but it was after about 120 to 150 hours that they
really came alive. They really need that burn-in time to reveal their
full potential. I’m not the patient type, but this time I was glad I
waited.
All the qualities the best 845s are renowned for are there. Let’s talk about dynamics first : a bit timid during the burn-in time, dynamics become quite exceptional after 100hrs and when tubes and amp reach their optimal operating temperature. They are extremely fast, with lots of impact and speed, speed and more speed. Extension in the bass is quite impressive and treble is exactly what you expect : not a trace of harshness but lots of details. Midrange is just exceptional, voices come alive to a point that I’ve very rarely experienced before. The timbres of acoustic instrument are very real, and that is quite obvious on violin or cello.
Soundstaging is outstanding, both in depth, width and accuracy. And there’s air between the instruments, something you can only hear when you are in the presence of real high-end gear. Pitch-black silence is another telltale sign of that.
On rock or blues, you can easily identify what guitar or amp is being played. A Strat sounds like a Strat, and there’s no mistaking a Les Paul or a Tele for anything else.
Comparing them to a pair of RCAs a friend brought around, the Linlai E-845s did at least as good as them in all fields, but they have a greater sense of immediacy, something that makes you feel more connected to the music….
Thanks a lot Rachel, those tubes are real keepers!
Cheers,
Eric”
[Linlai™ Global] tubes dimension chart
Positive Feedback review: Linlai™ Global E-300B vs. Psvane ACME300B
Review Juan C. Ayllon spent time with both tubes on his ultra high end Lampizator Big 7 Mk1 Digital to Analog Converter for ‘An Aural Indulgence‘
- “If vacuum tubes were wine, the Linlai would be a sophisticated French red Bordeaux blend from the Left Bank of the river Garrone in Bordeaux, France, while the ACME would be a top shelf Cabernet Sauvignon from California’s Napa Valley served in posh steakhouses.
- Don’t get me wrong; both the Linlai E-300B and the Psvane ACME 300B render rich, well-balanced presentations, and if I were not making conscious A to B comparisons, it would be easy to miss the differences. And, either vacuum tube will deliver luxuriant listening pleasures worthy of the most discriminating audiophile, enhancing high end tube gear performance and pairing them nicely with highly resolving components like the Pass Labs XP-12 preamplifier or X250.8 amplifier for a spectacular aural finish…”
Read the FULL REVIEW here.
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-Select 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-Select Special Edition) tubes 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
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.