Newproduction power tubes: Reliablity


There  isa topic going on  concerning power tube issues in his PL amp, 
Some of us have power amps with 4-12 power tubes,,  the higher number of the tubes in a amp means the more demand for  reliability.
The 2 countries making  the most power tubes are china and russsia, So basically we can say this is a Russia vs China shootout.

China has come out with incredible numbers of power tubes, varieties and styles. These are the SET tubes. Russia has a  far superior selection in the push pull category.
IMHO , as i do have a  push pull amp, I favor the russian labs as far as reliability. 
Here is where it counts, As we know, its no fun having a   multiple power tube amp, and hearing 1 or more tubes going bad. 
A  good tech is not cheap, nor so easy to locate.
So in terms of reliability/push pull, I have to side with the russian labs.
The one exception on russian power tube relaibility, is the russian KT150,, its a new tube and we have not yet had long term performance testing. It is  not a tube I am the least bit interested in. 


mozartfan
Sovtek makes their tubes in the old Reflektor plant in Saratov... EH is one of their marketing brands, so current 6922’s labeled Sovtek are the same tube as sold by EH

if you want a better sounding 6922 you should look at USA or Dutch Amperexes or Tesla old Yugoslav production ’labelled’ 32... otherwise seek true old stock (not current Sovtek owned brand) Mullard 6922 equivalents called E88CC
My problem is right now i have a pair of Sovtek 6922's in the cayin cd player and have muffed the sonics,, This is with my new Seas Thor xovers.. A pair of EH6922's arrive today and will find out just how the new Svet 6550's sound with new xovers, + superior 6922 tubes in the cd player,,also havea Tele pair of PCC88's arriving next week.
So maybe these Svet 6550's are not performing due to low level russian military style 6922's. 
As mentioned in another topic, all 6922's sounded near identical in the Cayin cd17, but when employing a  russian military style 6922, the sonics lowered drastically.


Tell ya what, Just read some of this review,,, read down,, eh655 vs eh88
He prefers the EH88 vs EH6550
so tahts what i will do, instead of getting the 6550 EH I'll buy the EH88 vs the Svet 6550.
Only 1 set will remain.

as i say in this topic, the 6550 and 88 are so close, near identical. 
I'll try adding a  set of EH88's  late next year (paypal debt will be near zero after paying all upgrades, new components) and will posta  review.
p
From 2002
longgg time ago
'https://hometheaterhifi.com/volume_9_2/power-tube-comparison-6-2002.html

Mullards are a bit warmer sounding

^^^^^^^^^^^^^^

Thats how me and  1 other  audiophile(quote: *I just didn't care for the GL's*, end quote) found the GL 88's. 
The GL are very popular, but just found the Svets a  superior tube.
have not tried the EH 6550;s.. I just might, ,,sometime after i get all my upgrades paid off/paypal debt.

This way I'll keep either the EH6550s or the Svets 6550.

have not tried the JJ KT88s or svetlanas, so can't offer any opinion on them. But have tried dozens each of  the electro harmonix KT88 and 6550, the Mullard KT88, and Tungsol 6550 all from Russia. All are pretty reliable, have some sonic differences, Mullards are a bit warmer sounding, EH KT88 a bit more open, etc. The Tungsol re-issue 6550s sound pretty close to the original US made Tungols.

The Shuguang factory has done their homework on plate and cathode construction materials and now understands how these affect the sound of the valve. Shuguang used to make the PSVANE tubes, but now PSVANE has their own factory so is making their own valves.

If you like the sound of the GL KT88s, you may want to try the PSVANE gray glass KT88s, more open, and detailed than the GLs, but will not last as long.

Should also state my amps are not stock. All have Jensen copper foil caps installed in the coupling caps and power supply locations, which also will affect the sonic attributes of the TUT (tubes under test).



I  just ditched my JJKT 88‘s for Genelex kt 77‘s and the difference is quite startling. The JJs didn’t sound very good in comparison. At all.
PSVANE T-II 12A_7 series.

^^^^ 
I have 2 pairs of Psvane's 12AX7's in boxes, really nice boxes,,, I am willing to dump at any price,,, i'll take 50% of what i paid,,,, good riddance....
China, nor russia can make a  good(=read GREAT sounding)  pre tube. 
The best pre tubes were made by Telefunken. 
From the Russian side, the GL KT8s are my favorite
^^^^^^^^^^


I had that tube, sent it back witha  generous restock fee, vivtubes says *thats the 2 nd matched 12 power tubes sent back in 1 month,,shop elsewhere please...*,,, anyway,, odd that my opinion was in line with another comment i read on a  forum (audio karma??)about the GL. Very popular, but he and I were in same opinion.


As for sonic qualities, the best sounding most organic output tube is the Shuguang Western electric Plus series (WEKT88; same series available in 6CA7. 300B, 845,. etc); This tube family blows everything else into the weeds sonically.

^^^^^^^^^^^^^^^^
One ebay buyer left a  comment on the Svet 6550's, * these Svet new production are equal to my previous WE6550/88's*
I believe him.
However,,, i will take  a  look at the WE88's Shuguang clones.
But lately my cash is spent in other places, new xovers, new tweets , caps, resistors, etc etc.
It will bea  very long time before i add new power tubes.
these Svet's are built like tanks and made to last, glitch free.

@johnss

good post

what amp(s) are you running your kt88s on? curious to know... i have a number of kt88 amps - several audio research and a primaluna - hearing the different sound profiles of the various compatible tubes is fun to experience

as for mozartfan... you are being kind... i would think even mozart himself would reject some of the close minded and narrow thinking expressed  :(
@mozartfan, This is quite the post. I have bought dozens and dozens and dozens of both Russian and Chinese made power tubes (mostly KT88s, but also many others). China has come a long way in their power tube reliability issues of previous years. Today's Chinese made tubes are much better than those of 5-10 + years ago.  Would still say the Russians are better for long term reliability. Have had to replace fewer of them in my amps over months of use.

As for sonic qualities, the best sounding most organic output tube is the Shuguang Western electric Plus series (WEKT88; same series available in  6CA7. 300B, 845,. etc); This tube family blows everything else into the weeds sonically.

But the reliability on these shuguang tubes is not as good as the  Russian made tubes (GL KT88 for example). So if you are going to run Chinese tubes, need to stock up on lots of spares, but you will get a nice sonic improvement by doing so. 

The Shuguang factory is in the process of moving so only real option for chinese tubes today is PSVANE, which are also good. Check out their KT88 gray glass tubes.  

From the Russian side, the GL KT8s are my favorite. do not sound as natural as the Chinese Shuguang WE varieties but are more reliable, and last longer.

For input tubes, really hard to be the PSVANE T-II 12A_7 series. They are reliable and sound exceptionally good.

for 6SN7 types, the Shuguang WE variety tops all, even NOS types.

best

mozartfan,


I am not sure if Buick building a factory in China can be considered stealing by Chinese. However, if under "Chinese Flu" you meant current Covid-19, the name you gave it is wrong. It has nothing to do with Influenza virus, or with cold environment.

Aside from that, just the other day I read about some Chinese car company that is planning to build a car manufacturing plant in the U.S.A. I forgot details.

Well with the Chinese Flu shutting down businesses across the USA, there will be plenty of opportunity for chinese tycoons to come snap up property on the cheap and move operations here, as the USA will soon have a
 huge labor market, ready and willing to work at whatever wages offered.
China is headed downwards, has no future, The USA is the only country that will surive the chinese flu
shut down
So makes sense to buy up cheap properties and move business here.
Cheap labor + shipping + warehouse etc etc = same as making here with cheap USA labor.
I am not interested in any chinese 88 tube, no matter how fancy the labeling. 
@ mozartfan, My new buick encore, is made in (China). This has been the world plan, 50+ years now. HELLO! :-)

Not doubting your word,, just had to google that fact,, yep says made in china,, HOWEVER,,not designed in china,, 
What I am saying the chinese can only copy things,, they can not invent ideas, They steal, The Buick is designed in the USA, built by cheap labor and robots in china,, Huge dif from  a  tube designed/built in china and a  tube designed/built in russia, China copies the russians, 
Russia makes the superior 88, which is the only  push lull i consider worth owning. 
The 90 is nice, but no cigar.
@glupson

i may have stated that point a bit too strongly... not to be too scary about this -- more appropriately: when a power tube fails, depending on how it fails and depending on the amp, there may be some ancillary damage -- would be a more accurate statement

like everything else, there is a learning curve and knowledge to using tube power amps
-- turn tube bias down when installing fresh tubes, then bias up gradually after 10-15 minutes idling (if the amp is manually biased)
-- be watchful when first powering up, for abnormal/inconsistent glow amongst the tube set (helps to lower the room lighting to see this obviously)
-- listen for any crackling, hissing or anything sounding abnormal at the amp or through the speakers - things may settle down if this appears initially
-- roughly note operating hours on power tube set over time

all the above is less critical (but should still be practiced) if the tubes have been pre-burned and tested by the retailer - good sources do this, sometimes for a small extra charge, it is worth paying for it for peace of mind

different amps have different protection circuits... primaluna among the best in this respect... the famous brand is audio research whose lovely, expensive amps do not have protection circuitry for the output tube, and so some (usually relatively minor) damage can result if a tube blows badly -- very fixable by a tech but still a pain to deal with (thusly, ARC tube amp users learn to be conservative in terms of replacing power tube sets pre-emptively and carefully noting the operating hours)


jjss49,

"...as mentioned, when a power tube fails there is often secondary damage to associated equipment... "

This is maybe the most precious info that many of us who have been curious, lurking, intrigued, maybe even considering, but having no experience with tubes could find on tubes.


Aside from that, just the other day I read about some Chinese car company that is planning to build a car manufacturing plant in the U.S.A. I forgot details.



EDIT: "Kandi says it is now actively looking to build an electric car factory in North America. And while it’s largely unknown to most Western consumers, Kandi is a big name in China. It’s a joint venture between Kandi Vehicles and one of China’s largest automakers, Geely Group, which in turn is the parent company of Sweden’s Volvo."



All Volvo S90 cars that you see in Europe are Made in China. I think that the same goes for those in the U.S.A.
@ mozartfan, My new buick encore, is made in (China). This has been the world plan, 50+ years now. HELLO! :-)
@mozartfan,   China does indeed make cars.

hard to fathom/believe, If you say so..
A chinese car...something on the level of a  Yugo,Fiat,  Chevy Chevette, Ford's 1980's crap, 
There is a  sort of relation, the more things a  country makes, the less quality in each product. 
Russia does not compete with china on consumer market goods, but the few things russia makes, are built  with reliability, A chinese 88 = is less reliable vs a  russsian 88.
This is my point of this topic.
Who of us can afford a  less than high quality 88 power tube?
I can't.

This is why i say, if you need SET tubes look to china, if you need  push pull, look to russia, This is the purpose of this topic. .

Excellent post, This is very helpful and based on your persoanl experience. 
Yes china makes everything,, with the one exception, automobiles, China can not nor ever will make a  car. 
Everything else they can make. But  by making everything, results in most things have less tahan acceptable standards. 
True, 90% of their power tubes will play wonderful for years,, But its that 10% that will give issues. Whereas russia as we know does not commercialize everything , but the few things , like tubes, guns, they make with a  far superior standard than does china. 
I am only speaking of 1 tube at the monent, The 88/6550, disregarding all others.
Russia's  new production of this tube, is slightly more musical and slightly more relaible. 
So why would you consider buying any chinese made 88??
when you get more bang for the buck with Svetlana's 88/6550?
Beats me. 
"Much prefer the Svet new 6550’s, the new plant uses the exact same equipemnt as the burned down plant,

NOS Svet 6550 = New Production Svet 6550, exact same tube, "              Wrong!      All New Sensor Corp got from the Svetlana Co was the name.      The St Petersburg plant, where their =C= tubes were manufactured, burned down and took the equipment with it (a shame).       Currently; The New Sensor tubes are actually manufactured at the former Reflektor plant (X-pul factory), in Saratov.       You may have conflated the rumor, concerning Mullard’s equipment, that this page mentions, with SED/Svetlana’s: https://www.effectrode.com/news/rubble-ruins/
chinese tubes have historically had a reputation for cheap manufacture and poor qc - back 10-15 years ago they were truly grim

russian makes have had their problems too

in both cases, quality has improved a lot... 

the chinese in general are state of the art in making things cheap, run on the hairy edge, and have failures... they have value engineered the world's supply of most everything, but such is way of capitalism and commoditzation

russian makes still have some soviet military mindset, make things more to last, thicker glass, more solid metal structures inside

this being said, the chinese and russians now also very much understand there is a good size market for quality - so in tube making, they have responded with higher qc, higher quality materials, made premium products as a result and of course they charge accordingly... that is good for us pursuing this hobby/activity

still, i buy from known sources who do secondary testing, i do not trust factory testing in and of itself yet - i won't buy from cheapest ebay sellers without a long reputation

as mentioned, when a power tube fails there is often secondary damage to associated equipment... so it is not just about the seller of the tube taking the tube back - they won't fixed your damaged amp...
I've used KT150s for the past couple of years without issue

Ok this is what we need to hera,, and would make sense the KT150 are in fact reliable, as jadis uses this tube in stocking a  few of their amps, jadis would never (except in the choice of EI KT90s wayyyy back when= mistake= bad tubes)  employ unrelaible tubes. 
Thing is, I did not care for the 150 in my amp. 
Almost damaged the Defy7,, as a  150 will not work in that circuit.

e GL KT88,

Tried em, didn't like them, return to vivatubes
Much prefer the Svet new 6550's, the new plant uses the exact same equipemnt as the burned down plant, 

NOS Svet 6550 = New Production Svet 6550, exact same tube,
is there a question in your post?

No, Its a statement of belief,, = that china is not well know for relaible, musiacl sounding tubes, Sorry to say, when it comes to tubes (except in SET tubes) china Loses.
I have Psvane 12AX7 in nice beautiful boxes, = lose to every EU NOS tube/every USA tube, 
Russian EH pre tubes are wonderful. vs china. 

Slovak Republic.

I havea  pair of JJ 6922's I refretfully won on ebay yesterday,, i will posta  commebt, Maybe my prejudice will change,, but I really do not like EI/JJ czech/East EU tubes, generally speaking
I've used KT150s for the past couple of years without issue.KT88s have been GL and JJ,no issues.
"As if we needed any more reasons to side with Russia over China."

For many people being married to a Russian is not a reason enough to pick Russian tubes over Chinese.

The Winged =C= (SED) Svetlana plant made some very reliable power tubes.      I hated to see the company fold, when their plant burned down.     Comparing them to my NOS GE and Sylvania 6550 iterations; their presentation was quite acceptable.     Used a couple octets, from Upscale, myself.     Now, unfortunately; most of what’s left are factory seconds.     As for me, if there’s a new sweetheart on the block; it’s the GL KT88, Russki repop.        They yield most of what I got from the NOS valves, in sound, and (over the past couple years) have displayed no reliability issues.
As if we needed any more reasons to side with Russia over China. 😂😂😂 My all-time favorite, happily #1 in sound quality, reliability AND cost, is JJ made in the Slovak Republic.