SP-14 Shuguang Black Treasure CV181z

I notice that this tube is now being touted for the SP-14. Anybody have any experience and/or opinions?

I settled on a quad matched NOS set of Sylvania gta, tall bottle, chrome tops (ca 1950) and am pretty happy, but always willing to listen.

Experience - and Opinions - 'R' Us.
The Black Treasures I have used for 8 months in the two left positions in my SP-14. These are the critical volt-amp stages. The other two are buffers, and less prone to affecting SQ. Some may disagree, but there is no absolute reason why one needs a matched quad - two matched pairs will do. And they need not be the same brand or type.
After a rather long break-in period, these Shuguangs have given much joy. They are robust-sounding, very complete. From what I can see, the better Chinese factories are now making tubes of quite high quality, which has not always been the case. These tubes are not cheap, and it appears one must take care in sourcing them. Some say that the best method is to rely on our trusted North American distributors who can carefully match them. But these guys generally charge a 100% markup for the service.
The other drawback is their size. They barely fit under the SP-14 cage. My solution is to prop up the unfastened cover from the rear with an inch of shim. This may or may not be strictly necessary.
My own experience with the U.S.-made NOS or used tubes is that they generally sound mellower here. There are so many 6SN7 types out there that generalizations are worthless. There are incredible tubes for $10 a pop. There are ho-hum ones for $75.
I have yet to have, or hear of, a Shuguang BT 6SN7 which is either noisy or microphonic. That's nice.
Expect to pay upwards of $60 a pop for these. I believe they are fully worth it. I have tried two dozen or more pairs of various 6SN7 types in the SP-14 volt-amp holes. These Shuguang BTs are my favorites. And you should be aware that there is a level above these called "Natural Sound" or "Sounds of Nature" which may be even finer.

I share Kentley's admiration of the Shuguang CV-181 types.  I only have experience in the center position of the ST-120.  

The common Shuguang is the Black Treasure CV181-Z while the upscale CV181-T being the "Natural" series.  The "Zs" are more smokey sounding while the "Ts" seem to have a touch more high frequencies.  I love vocals with the "Z" at the cost of less top and slightly less soundstage compared to the "T".  Both have good bass and very low noise.  

These tubes take forever to run in and open up so be patient.  There's also the Psvane CV-181 but can be much more expensive.  The CV-181 though has found a permanent home in the ST-120.

Thanks for the information. When I built the sp-14, I bought a box of around 20 6sn7s on ebay for around $40; all tested good. So I had the opportunity to listen to numerous combinations of American tubes: Sylvania, RCA, etc. Also, I got a close-out deal from Sonic Craft on a pair of Russian Electro-Harmonix. The Sylvanias had the most appeal; so I went with the earlier black plates . Didn't like the E/H tubes at all, too harsh, but maybe they would improve with more break-in time.  

As I said, I'm always willing to listen, so I think I'll look at the Shunguangs and see what can be had. Obviously, buying a single pair for the gain sockets is the right way to go (got the quad Sylvanias for the same price as two matched pairs). I built the chassis with the tubes on top, so there's no issue with height; and appearance is a factor. Any suggestions on sources would be appreciated.

I see the Black Treasure on da bay for around $60, direct from China, from several sellers. US sources double that ... I'd only be using the one in my ST120, so matching isn't a problem.

Worth a chance?

PS ... still real happy with my $10 RCA coin base 6SN7 ...

sKiZo wrote:I see the Black Treasure on da bay for around $60, direct from China, from several sellers. US sources double that ... I'd only be using the one in my ST120, so matching isn't a problem.

Worth a chance?

PS ... still real happy with my $10 RCA coin base 6SN7 ...

I wouldn't buy Black Treasures off Fleabay. Better to deal directly with a reputable Chinese dealer, although you'll wait 6-8 weeks for delivery. They are righteous tubes. OTOH, if you're happy with your RCAs, why fix what ain't broke?

The old 6SN7s have been a disappointment.  I have functioning (but used) examples of Bad Boy, Ken Rad, Sylvania, etc.  Some are very microphonic, noisy, or I just did not like their frequency response. 

The Asian company I used to purchase Shuguang types has twice supplied good tubes that last a long while.  You can get single Black Treasure CV181-Z for $65 and Natural Sound CV181-T for $75.  I believe shipping was free and received in about one week (USA-California). 

On my last order I also purchased Natural Sound 12AU7-Ts that are clean, neutral, and make great phase inverters in the ST-120.  They are well built with three mica supports.  Psvane makes good 12AU7s (two mica supports) but cost 50% more. So I am off the vintage tube trail for a while. 

Google search the web for "CV181-T tube-sale".   Look for tube-sale in the URL name (about 5 listings down in the search list).

I've been running a pair of Shuguang Nature Sound 6sl7-T in my Holger pre-amp since May of this year. I play my system daily for a few hours at night. The tubes sounded very good until a few weeks ago when I noticed a slight hum from my speakers, only detected in dead quiet. About a week ago one tube started to hum a lot more till when you could hear it with soft music playing. I chased the hum back to the Shuguang Nature Sound 6sl7-T tubes. They were great while they lasted, just a tick over 6 months. Just my experience with them.

TM

not Shuguang, but I just ordered a set of PSVANE HiFi Series 6SN7's as well as PSVANE UK-6SN7's, and shall try them out on my model Elvis 60W/CH power amp.
I have heard some good things about those tubes, and although they apparently require quite a few hours of 'burning in', they are supposed to sound really good once 'settled' in.
If they turn out to be good, I will build a small octal tube 'burning in' rig, to run these tubes for anything up to 100hrs before using them in my custom builds.
Will keep you all posted. It will be after Christmas before I'll get a chance to run them in my amp, as I'll be heading 'downunder' to visit family and friends.
Just as a side note, and an unabashing plug,    for those here who happen to own Revox reel to reel tape decks, we now sell comprehensive upgrade kits and custom face plates for the most popular models, details on our web page  

I'm rather partial to the PSVanes. Like the Shuguangs, they do require a bit of run-in time, although not nearly so long. They should be sounding pretty good after 10-20 hours or so.
For either tube, just stuff 'em in the splitter holes for awhile before  moving them out front to the VA slots.
I would put the PSVanes up against Sylvania's best NOS from the 1950s. As to longevity, who knows? If mine make it to 5k hours I'll throw a party

Today I received a new Shuguang Natural Sound CV-181T for use in my ST-120 center driver hole. This is the top-of-the-line, at $75 a pop. Right out of the box it sounds stunning and more robust with great high and low extension, compared to the Russian Melz metal-based "6SN7" I had been using. So these Chinese new-manufacture tubes are a force to be reckoned with. Now we'll see how long it lasts, what with my punishing regime....

Kentley wrote:Today I received a new Shuguang Natural Sound CV-181T for use in my ST-120 center driver hole. This is the top-of-the-line, at $75 a pop. Right out of the box it sounds stunning and more robust with great high and low extension, compared to the Russian Melz metal-based "6SN7" I had been using. So these Chinese new-manufacture tubes are a force to be reckoned with. Now we'll see how long it lasts, what with my punishing regime....

Where did you purchase the tube? Were you satisfied with the service and shipping? Price seems reasonable, wonder what the supplier would charge for matching a pair.

Thanks,

wanders: "Where did you purchase the tube? Were you satisfied with the service and shipping? Price seems reasonable, wonder what the supplier would charge for matching a pair."

Here's my source. Delivery took only two weeks to New England. http://stores.ebay.com/psvaneshuguang/

yes, from what I have read and heard, PSVANE and Shuguang have really gotten their stuff together these days, they've come a long way.
Sound wise, it seems they are just about as good as any of them.
The only thing that still needs to be proven is life span. I have heard and read both good and bad reports, almost a 50/50 split.

I cannot recommend Natural Sound KT-88T tubes for reliability sake.  I bought 10 of these tubes over the last four years and three failed within a few months of putting into service.  Sounded good while they lasted but never again for me.  Only tubes that have failed catastrophically since owning the ST-120.  YMMV

My first Black Treasure CV-181 lasted about 9 months before developing occasional mild pops and rushing noise similar to a leaky capacitor.  It was a damn good sounding tube so hated to see it go.  But all other CV-181 types have held up well.  So I always keep a spare!

arledgsc wrote:I cannot recommend Natural Sound KT-88T tubes for reliability sake.  I bought 10 of these tubes over the last four years and three failed within a few months of putting into service.  Sounded good while they lasted but never again for me.  Only tubes that have failed catastrophically since owning the ST-120.  YMMV

My first Black Treasure CV-181 lasted about 9 months before developing occasional mild pops and rushing noise similar to a leaky capacitor.  It was a damn good sounding tube so hated to see it go.  But all other CV-181 types have held up well.  So I always keep a spare!

Wonder how these would last in a preamp (sp-14) vs. an amplifier.

wanders wrote:
Wonder how these would last in a preamp (sp-14) vs. an amplifier.

They may last as long as any other tube.  Usually buying tubes mail order you just have to accept the risk of premature failure and eat the cost.   You can purchase from a reputable dealer with some kind of warranty but at most likely at a higher cost.   But the warranty period is usually short - like 3 to 6 months.  But I once returned a tube to a US dealer that clearly had a lot of hum out of the box.  They replaced it without question.

I would avoid low-price deals on Ebay.  Those tubes could be factory 2nds or knockoffs.