Tubes Asylum: REVIEW: Shuguang / SuperTNT 2A3B Tubes by NickChua

Model:	2A3B
Category:	Tubes
Suggested Retail Price:	$49.95 per pair
Description:	Single Plate 2A3B
Manufacturer URL:	Shuguang / SuperTNT
Model Picture:	View

Review by NickChua on August 28, 2004 at 09:01:15
IP Address: 219.95.158.46

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for the 2A3B

The review covers the new 2A3B develop by Shuguang. Its structure it is a very close copy of the Sovtek 2A3 single plate with some minor difference. The review directly compares Sovteks versus the Shuguang as both are in the same market price region. The Shuguang has a black plate unlike Sovtek which has a grey plate. However the older 2A3 also has a black plate too. In my books, black plates do sound better perhaps electrons are attracted to darker surfaces better compared to grey in color which has more white in it . Same principal where black shirts on a sunny day equates to a hotter person. Aesthetically the black plate looks sexier and more posh compared to the duller greys of the Sovtek. The internal pins do look of a high grade where they are shinny in color compared to Sovtek which are duller in color perhaps showing signs of oxidation before they were put into assembly. It is to be noted that the plate length is the same for both 2A3B Shugugang and Sovtek 2A3. The bases are perhaps the same type where a black plastic thingy is used. Does not really shout out high-end with that type of base. Hopely they would rebase the tube with a ceramic type. I have seen some mesh plate photos of the 2A3 by Shuguang and they incorprate ceramic base and gold pin. Combining the elegant ceramic base and the sexier black plate I think Shuguang would have a killer tube.
Build Quality
Internal construction is done to a high standard, where welds and joints looks studier and well form and aligned properly. Definitely some thing I do not expect from a stereotype Chinese tube, no pun intended. Comparing directly to a EH 2A3 Gold Pin tube the construction level is reasonable but there is still room for improvement to reach EH level especially the base and the letting on the tube. Got to love those Ceramic bases on the EH. Comparing the old Shuguang Double Plate and the newer Single Plate reflects the increase in workmanship level where the Double Plates where of a lower quality. Comparing the Shuguang 2A3B and the Sovteks, it amasses me that the Shuguang actually have a better build quality. The Shuguang has a much better spot welding compared to the Sovteks. Probably the technology for TIG wielding for cars has been incorporate here. However one factor that tends to upset their increase in workmanship are the pins of tubes. The pins of the tubes looks oxidize and not brand new newer perhaps oxidizing during shipment. Hopefully Shuguang can look into that perhaps a better coating for the pins. Other than the pins, for Shuguang to do so relatively well in improving their workmanship, I salute them and hopefully they will continue to improve they workmanship. Who knows KR workmanship at a Shuguang price? I hope as I canâ€™t afford KR tubes.
Packaging
The packaging supplied for the 2A3 is the best economical 2A3 packaging I have seen. Firstly I hate the Sovtek boxes where they need to be close to form the whole box. Also the paper quality and thickness is thinner than the Chinese version. All in the Sovtek boxes always gives me the impression of a cheap tube. The Shuguang 2A3B comes in a white box unbranded but has a nice study feel to it. I hope in the future Shuguang will consider adding some graphics to the box as its kind of plain if you ask me. However on any given day I prefer white boxes to cheap Sovtek boxes but they do have brand image though. The best part about the Shuguang packaging is where the tube are individually wrap in bubble wrap for shock absorption. This really helps in reducing damage due to shipping from taking place. When I receive the tubes in the mail, the box holding the tubes looks like it took a journey throughout the world, worn and beat up, the tubes were fine though. It shows to great lengths the distributor SuperTNT took to ensure that the tubes do not get damage in the journey. Sometimes mechanical vibration due to shipping tends to unsettle some mountings or fixtures in the tube and increase the microphonic level
Test Certificate
In both the Shuguang 2A3B tubes I received, a test certificate was inserted in the box. The test certificate shows the serial no of the tube that was made, mine was 0015 and 0018. Most important details in the certificate are the test results for each tube that has been tested. Details tested are
â€¢ Test Conditions
o Filament Voltage
o Plate Voltage
o Grid Voltage
â€¢ Test Result
o Direct Interelectrode Capacitance tested at 400Hz
 Grid to plate
 Grid to filament
 Plate to filament
o Plate Current
It feels good knowing each of your tube purchase from SuperTNT is tested for in working condition and matching, they even test the Interelectrode capacitances. Even the EH does not provide any form of test done of the tubes. Most of them are match by the dealer using a tube tester. I did not come across any where that the tube is tested at its known sweet spot for matching further more noting down the test conditions. By the way the 2A3B was tested at 250.3V Plate Voltage, -45V Grid Voltage and a resultant current of 56.3ma.
Electrical Tests
Point to note, the Shuguang 2A3B plate current at the 250V Plate Voltage shown above is quite close to the RCA value of 60ma tested at 250V Plate Voltage and -45V Grid Voltage. The Shuguang plate current of 56.3ma is close to the RCA ratings. I believe the Shuguang 2A3B is closer to the RCA specs than the Sovtek. To achieve a plate current of 60ma at the 250V plate voltage a grid voltage of -36Volts was used to achieve this same plate current level. However the Shuguang 2A3B filament has an unbalanced coating for the filament, I find it difficult to null the hum thru the use of the hum pot. I suggest to use only DC type current source heater for this tubes to prevent a noisy amp. Their build construction picks up more noise than the Sovtek. The Sovtek 2A3 when heated with AC shown no signs of hum, the amp was hum free even thru a 97db speaker. No hum pot was used but two resistors of the same value were used for a center tapped. Perhaps this can be concluded as the coating of the filament is even on both of ends for the Sovtek. Hence there is no hum reduction gain from using DC on the filament perhaps a hum pot for a better nulling only. Hopefully Shuguang looks into this matter as I love AC heaters as most other audiophiles too. Point to note is that I have run the Shuguang at above 15Watts and they still do not go red platting. So for higher power 2A3 amps that biased their tubes hard donâ€™t fret the 2A3B is able to be punished that way without failing. The 2A3B tubes are sent thru a 24 hour burn in period for catching early failures. Hence both the tubes I received were still match even after 100 hours of running in. Unlike the Sovteks which do not receive their due torture during manufacturing process, I have known friends who have Dud Sovtek and EH 2A3 tube (red platting tubes). These tubes fail when being played on a normally biased 2A3 amp. So Caveat Emptor when buying from tube dealers who do not have long burn in time for their tubes.
Sonic Character
The Shuguang tubes has a nice neutral feeling too it. The audio range is very balanced where no frequency range is attenuated or enhanced. This is often a very good aspect for a tube to have a neutral feeling too it. Hence the sound of the driver comes thru more apparent as the 2A3B adds no coloration of its own. The 2A3 from Sovtek offers a thicker bottom end at a cost of Highs. However I find that aspect of Sovtek to be a bad thing as it upsets the tonal balance of the tube. It is noted that the EH version improves on this where there is less coloration on the bottom end and a balanced high frequency. The singers sound like themselves no extra sugary coating on the voices AKA 300B. What I like best about the Shuguang 2A3B tube is that is a very dynamic and punchy tube not laid back. The attack captures you and releases you quickly unlike some other tubes where the attack is slow and non-evolving. Pace, Rhythm and Timing of the 2A3B is one of the best among the other 2A3 brands. This is extremely enjoyable tube to play classical orchestras especially the strings. I can feel the rubbing of the violin strings being bowed while the orchestra is playing on. The speed of the violins is like the real thing being played in the concerts not slowed down like other 2A3 (Sovtek, EH, Shuguang double plate). The Sovtek version is like a very miniature 300B sound, slow, tubey and thick. It tends to make the bass boomy, double bass on Kind of Blue, Miles Davis was bloated and only the sound of the box is heard not the strings being plucked. These traits are often considered good in my books, however too much tends to spoil the music and the Sovtek clearly ruin great classics being played. It is like each string instrument has a bigger box which makes the sound bigger than it is supposed to be when played thru a Sovtek. The EH version has a nice speed to it like the Shuguang 2A3B at a high cost only. However this traits of Pace Rhythm and Timing might be considered a fault as the pace is faster and slightly less relaxing but too me it is still very much enjoyable. Sibilance in the midrange and the high frequency was not detected when playing vocals like Diana Krall, Norah Jones and etc. However comparing to the Sovtek 2A3, it has a sibilance in the vocals which it tad annoying. Because of the speed of the Shuguang 2A3B is good, Rock pieces like the Bullet and the Butterfly wings from Smashing Pumpkins sounds fantastic as the riffs and chords are heard with great accuracy and speed. When listen to rock you have the notion of rocking in your chair, not dull and following asleep. I find the Sovteks tend to put me to sleep, good for the insomniacs out there. The EH has a nice sparkly to it and the feeling of waiting to hear more which slightly edges out the Shuguang 2A3B. With Dance music where heavy BPM and low bass, this is where the Shuguang 2A3B might fall slightly short compared to Sovtek The Sovteks bottom end enhancement tends to have a fuller and richer drum machine notes while keeping pace slower. I find for endless hours of techno music being played like Paul Van Dyk Out there and back, the music must have a nice bottom end and a slow pace so not to risk listeners fatigue.
All in I gladly recommend this tube 2A3B Shuguang to anyone, it a good bang per buck when looking for a cheap and decent sounding 2A3. Before Shuguang came out with the 2A3B the Sovteks have often being considered the best bang per buck for a 2A3. Now Shuguang has taken their place, for almost the same price you get a neutral yet dynamic tube that tends to add some form of tube sound coloration as well as the speed and dynamic of the solid state. You get best of both worlds when this tube is used over other 2A3 types. When speed, dynamism and neutrality is your game then this is the tube for you.

Product Weakness: Noisy with AC heating needs to be run on DC. Ugly base structure
Product Strengths: Neutrallity, Dynamism, Speed,Attack and PRAT( Pace Rythm and Timing). Nice black plate and blue glow when the lights are off

Associated Equipment for this Review:
Amplifier:	DIY GM70 SE
Preamplifier (or None if Integrated):	DIY 6SN7 Parafeed Output Trans
Sources (CDP/Turntable):	Marantz CD63 with external DAC 1545 DIY and Acoustic Research Turntable using a LINN BASIK ARM 5 and a REGA SUPER ELYS cartridge
Speakers:	DIY FOSTEX 206 97DB
Cables/Interconnects:	AUDIO MAGIC with copper foil speaker cables
Music Used (Genre/Selections):	Rock, Techno,Classical, Jazz and Vocals
Room Size (LxWxH):	20 x 15 x 15
Room Comments/Treatments:	DIY BASS TRAPS
Time Period/Length of Audition:	100 Hours
Type of Audition/Review:	Product Owner

Product Weakness:	Noisy with AC heating needs to be run on DC. Ugly base structure
Product Strengths:	Neutrallity, Dynamism, Speed,Attack and PRAT( Pace Rythm and Timing). Nice black plate and blue glow when the lights are off