I read this review, along with a few other, and want to know if anyone can quantift this review, or add anything to it.
http://www.enjoythemusic.com/magazine/e ... 7_kt88.htm
Shuguang Treasure Series Vacuum Tubes 6CA7 And KT88
These Aren't Your Grandfather's Fire Bottles
Review By Nels Ferre
Shuguang, China's oldest and largest manufacturer of vacuum tubes has been in business since 1958. In 1983, Shuguang partnered with western firm LG. As of 2005 Shuguang had developed 120 types of vacuum tubes, and manufactured over 70 million units. A notable fact: Shuguang has produced eighty percent of 300B tubes ever made.
The Grant Fidelity Connection
Located due north of Montana in Calgary Alberta Canada, Ian Grant and his partner Rachel Zhang import both electronics and accessories directly from China for sale across North America. In and of itself, this does not sound all that news worthy; after all there are importers of all types of electronics worldwide. What is interesting is that Ian and Rachel travel to China and visit the factories in person.
Ian's background is music, with over 25 years in both consumer and professional audio. Rachel's background is business. Audiophiles are only a part of their target audience. Their larger goal is to offer something better than what is found at most big box stores, at an affordable price. As Rachel put it, "Probably 99 percent of the world's music lovers didn't have a chance to listen to real high fidelity yet. We hope to bring the ultra sound of music to average consumers with an average sized wallet." Ian and I both are old enough to remember the days when one's audio systems were the focal point of nearly everyone's living room, and they are doing their part to bring that back. Products are sold online, by phone and through a network of independent home demonstrators.
I had been aware of their firm for a while, and when I saw that Grant Fidelity was the exclusive North American dealer of the new Shuguang Treasure Series vacuum tubes, I gave them a call. Initially, I was shipped a quad of 6CA7 Treasures- think "fat bottle" EL34 ($240/ matched pair.) Later a quartet of KT88s ($300/ matched pair) was shipped.
Obviously, the Shuguang Treasure Series tubes are pricier than most new production tubes. Shuguang designed and manufactured the Treasure Series to commemorate their fiftieth anniversary, and they are not rebadged for anyone else. According to the "poop sheet" there are 65 differences between the Treasure Series and any other tube of the same type from any manufacturer. The obvious difference is that the tubes are black. I initially thought there was black paint in the inside of the glass envelope. It is not paint- it is actually a carbon coating designed to trap any stray electrons inside the glass. I am fairly confident that the carbon coating also helps reduce micro phonics as well. Unfortunately, I am unable to tell you about the other 64 differences -- the carbon makes a visual comparison of the tubes to others impossible. It also stops less scrupulous sorts from manufacturing counterfeits, a common practice in China. I still remember seeing pictures of "Sonny", "Maxwell" and "KDK" blank cassettes sold in China back in the early 1980s.
In an effort to reduce cost, the tubes are shipped in regular boxes (no wooden presentation cases here, although the tubes are visually worthy.) Treasure Series Tubes are covered by a 30 day guarantee; a one year extended warranty is available for a nominal sum. The factory recommends a 300 hour break in period.
Both quads of tubes worked flawlessly during the review period. I was rather apprehensive about the KT88s, as I have experienced a 25 percent failure rate with KT88s in the past. In fact, my current KT88s were purchased used with approximately 200 hours on them, my logic being that if they made it that far, they would be fine. That was over a year ago, and they have many more trouble free hours on them since without missing a beat.
The Test Amplifier
Because a review of vacuum tubes is useless without a point of reference, a bit of background on the amplifier used is in order. My reference power amplifier is the Bella EXtreme 3205, a push-pull pentode that can accept either a quad of EL34/6CA7/KT77 tubes biased at 40mV or a quad of 6550/KT88/KT90s biased at 50mV. Using EL34s, the 3205 will produce 50 watts per channel; use of KT88s will give up to 60 watts per channel. The amplifier is fitted with Russian Electro Harmonix 12AT7 driver tubes and new production Mullard 12AX7 input tubes. (From what I can tell, the Mullards are rebadged Sovtek 12AX7LPS tubes- a personal favorite.) My review of the Bella Extreme 3205 amplifier can be read at this link. The tubes I always use are Shuguang's garden variety KT88s. Other tubes on hand are Sovtek 6550s, and Electro Harmonix EL34s.
It may seem odd to use a quartet of tubes that sell for $480 to $600 in an amplifier that last sold for $1599. To me it makes perfect sense for a couple of reasons. First, I know this amplifier very well as it has resided in my system nearly exclusively for the last 2 years. Additionally, I subscribe to the belief that a system is only as good as its weakest link. As the amplifier has already been "hot rodded" it makes sense to "hot rod" the tubes as well to wring every bit of performance from the amplifier. Not that there is anything wrong with the tubes that I regularly run, far from it, but there is room for improvement, As they say in racing circles, I ran what I brought.
All of the tubes were biased after letting the amplifier stabilize for a period of fifteen minutes, then again at one hour. The voltage was checked again after 24 hours and finally again at 72 hours. All of these checks were performed at the same time, late at night to get the best quality AC possible. One thing I did notice very quickly- the Treasure Series tubes- either variety- were much less prone to drift than the other tubes I have on hand. My tubes can drift anywhere from 1 to 3 mV. The Treasure Series tubes drifted much less, never exceeding 1mV from where the bias was initially set.
The NOS Game
Ian tells me the target audience for these tubes is the "NOS Crowd" not only for audiophiles but also electric guitar players. The thought process is that the Treasure Series Tubes can be used as a high quality "everyday" tube, saving NOS rarities for special occasions, either in the home or recording studio. Me? I don't subscribe to the idea. First, at the price, the Treasure Series tubes had better be pretty special in their own right... to the point that searching out NOS (New Old Stock) tubes becomes moot. The only way I really see the value in NOS is for those applications where no current production tube exists such as the MHDT vacuum tube DACs. Other than that, I feel one is subjecting themselves to the unknown- is the tube really new because someone who says they have a tube tester and knows how to use is says it is? Even if it turns out the tubes are NOS as advertised, then one risks getting hooked on a tube that is no longer manufactured. There is also the issue of supply and demand- as the supply of NOS tubes continue to dwindle, the price f the remaining available tubes will escalate. I prefer to stick with a tube that is easily replaceable, when the need arises. The Treasure Series will remain in production for the foreseeable future. I have been told the factory expects it to take approximately five years to recoup their investment- a good thing for consumers.
Get On With It! Are They Any Good?
Two words: yes and yes. Beyond good... these are great! I was thinking about vacuum tubes recently during my morning commute. (Sick, I know... Leslie calls my checking out audio "stuff" on the internet "Audio Porn" and has been known look over my shoulder to read the text of technical articles in a sultry voice. I rather like that! Like I said, sick. At least I realize it.) Anyway, I was thinking that vacuum tubes are like beer. This has nothing to do with the obvious, that they have both been around for a long time and come in glass bottles. It's more about both having differences among themselves, while remaining similar. Everyone who likes beer has their favorites. You may cringe, but I actually like Budweiser: it's a decent tasting beer at a reasonable price. When I want something a bit nicer and more full bodied, Sam Adams is a nice choice. Beyond that, I like Black and Tans (real ones that are made with Bass Ale and Guinness Stout, not that swill that comes premade in a bottle.) In winter months, I like Guinness Stout, but I find it too heavy for hot summer months.
These tubes fall into the same analogy. Electro Harmonics EL34s are similar to Budweiser- satisfying, cheap and plentiful, but there are better. They are a bit rolled off at both frequency extremes, highlighting the midrange, whereas my regular grade Shuguang KT88 tubes are somewhere between a Budweiser and Sam Adams- more flavor, more texture, more satisfying- in my system, a better all around choice. Better bass extension takes some of the focus away from the midrange- just a more balanced tube. The Treasure Series EL34/6CA7 was the surprise- where I can drink Budweiser all summer long and be happy; I find it difficult to listen to the audio equivalent. I am just not a big fan of EL34s. I found that I preferred the Treasure Series 6CA7 to the regular grade Shuguang KT-88 in my system for their extended highs and midrange beauty. I appreciated the Treasure Series' bass texture, but I found myself wishing for more authority. That is where the Treasure KT88's extra bass grunt came into play. I found these to be my favorite of the lot, by a big margin. I found them to be the most balanced of the tubes I have on hand top to bottom, with incredible detail. Dynamics, both micro and macro... check. The Treasure Series KT88 really has it all — just like a Black and Tan. Keep in mind, I am not slighting the Treasure Series 6CA7 — I still preferred them to my usual tubes. This is high praise.
I also have a quad of Sovtek 6550s. I find that 6550s, at least the ones that I have heard, have a "hardness" that the KT88 doesn't have. The KT88 to me is a generally smoother tube. Using the beer analogy again, the 6550 is like Heineken as it would be better without the aftertaste. And what, to me is the audio equivalent of Guinness Stout? A nice setup of vintage tube electronics maybe paired with a pair of vintage Klipsch speakers. Slower, warmer and mellower. There is plenty of musical goodness there. It is just not something I want all of the time.
I mentioned detail. The Treasure Series tubes have it. More importantly however is nuance. There is a big difference. Detail to me is hearing a cough, a squeaky piano pedal, or making out some previously unintelligible sound from the audience in a live recording. I like hearing everything that a recording has to offer, both good and bad. But nuance- that is something special, and that is exactly what the Treasure Series tubes, at least the types that I had here, offer in spades. As an example, let us play the Beatles "I'll Follow the Sun" from Beatles For Sale. Paul is the focal point here, but I found myself drawn to John's beautiful harmony. This is just one example- it is as if parts of recordings that are behind the main theme of the music are brought just a bit more forward, to blend better as opposed to being relegated to the background. The difference between the Treasure Series is large, not a difference in "flavor" like what usually happens when tube rolling. With the Treasures in place, the Bella Extreme 3205 sounds like a different, far more expensive amplifier. And I this case, different is better. With the Treasure Series KT88s in place, I would put this amplifier up against any $3ooo to 4000 amplifier I can think of. It may not win the shootout, but I highly doubt it would be embarrassed either.
The biggest difference between the Treasure Series and the others on had was in their ability to portray space and ambience within a recording. I listened to lots of different music, but for the most part, I ignored the "sonic blockbusters" one usually sees referenced in a review. See, I was having too much fun listening "regular" recordings- no gold CDs, very few heavy slabs of vinyl, just the recordings you might find at a garage sale. As I write this sentence, I am listening to the B52s Wild Planet. [Warner Brothers LP BSK3471] and although the album is clearly a product of many overdubs, I was shocked at the ambience I had missed on previous listens, especially with the vocals. The same thing happened with my CD copy of Jewel's Pieces of You. This doesn't happen with every recording, so it is not that these tubes are adding anything. I just had more fun listening to music with them in the amplifier, and had a harder time tearing myself from the system.
A couple of nights ago, I listened to Jackson Browne's Running on Empty, which was recorded at Merriweather Post Pavilion in Maryland, a venue where I have seen a few live shows. I closed my eyes, and found I could nearly "see" the show. I am really curious at what is going on inside those glass bottles.
One of Leslie's favorite tracks is Etta James' "At Last." Not a hi-fi chestnut by any stretch of the imagination, but if a system does not do it justice, count her out. She liked the track with the 6CA7, and then I switched to the KT88. I cued up the track again, this time by remote, searching the hard drive's database with my iPhone. When it started playing, I knew something was instantly wrong. I looked down at the screen and realized that doing the search by song title, I had selected a version from a compilation album- one that clearly used a tape far removed from the tape used on the Etta James CD we normally listen to. I hate to use the foggy window cliché, but it is close. Playing the "correct" version, we both preferred the Treasure Series KT88s to the other tubes in the house, with the other black bottles second.
You will notice that none of these tracks would ever be considered audiophile grade. That is what I found so special about the top level Shungungs they brought me closer to the music, they brought me more musical enjoyment no matter what music I played, be it Leadbelly from the 1940s or what is spinning on the turntable right now- Buena Vista Social Club [Classic Records RTH-79478] This is fantastic! I sincerely wish you could hear this. The sound is dynamic, big and super realistic. Let us see, $1900 worth of Salk Signature Sound Songtowers fed by a $1600 power amplifier stuffed with $700 or so of tubes. This is fed by a Juicy Music Peach tube preamplifier ($1695) fronted by my SOTA/Rega/Dynavector analog rig ($3500) which in turn feeds a Project Phono Box II ($170). Yes, you read correctly. All this musical goodness and my phono stage (although very good for the money) is a cheapie. A friend is finishing the kit build of my DIY Hi Fi Supply Cole tube/transformer based phono preamplifier ($1500). I hope it is as promising as it appears to be, but it could not be finished in time for this review. Maybe the Treasure Series Tubes are better than I think, which is pretty gosh darned good.
I do have a couple of dislikes. Both quartets of tubes were shipped as matched quads- a good thing. Someone affixed labels to the 6CA7s that became hard and brittle. All 4 labels fell off of the tubes and down inside the amplifier (!) I was able to fish them out, but they were so brittle that none came out in one piece.
While both types of types of tunes served the music equally well (in different ways) I did have an issue, sound wise, with the Treasure Series KT88s. Their very extended top end tended to accentuate surface noise when listening to well worn LPs. I guess my copy of Donovan's Open Road [Epic LP E30125] is more worn than I realized. It looks great visually, and is clean as a whistle, but noisy as all get out. That said, I still preferred the album with the Treasure Series KT88s, even taking the noise into account. It may be time to search for a better copy.
While certainly not inexpensive in absolute terms, Shuguang's Treasure Series 6CA7-Z and KT-88Z tubes are both stellar performers. When compared to the going prices for NOS tubes from the usual suspects (GE, Genelex, Tung Sol, etc.) the price of the Shuguangs are right in line. Compared to (at least based on price as I have not heard them) the EAT KT88 Diamond at $1395 for a quartet, they are a stone cold bargain. While the Treasure Series 6CA7 is the only EL34 type tube that I have ever heard that I could easily live with long term, their KT88s (to my ears and taste) are even better yet. Though I prefer the KT88s both models are very highly recommended.
Type: Amplification vacuum tubes
Shuguang Treasure Series 6CA7: $240 / matched pair
Shuguang Treasure Series KT88; $300 / matched pair
Optional Extended Warranty available at extra charge