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KT-88Z Treasures in VRDs


BE36

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Rob,

Tested those Genelax and indeed two are shot from internal defects. One has a constant internal short which is probably the one that died with a spark show. The other has a intermitttent short and tests extremely week compared to the other two that test fine.

I'd still like to know where you bought them before I place the blame on the Genelax reissue tubes in general? All modern production tubes have quality control issues that should be weeded out by the tube dealer selling them since the factories seem to refuse to do so. Most of those dealers sell the defective tubes off to eBay sellers rather then hassle with sending them back for refund. Then they end up in the hands of consumers and the tube ends up with a bad rep!

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I'd be calling Jim McShane if it was me....

Information he might want

Amps run the tube at 55mA @ 500V on the plate in UL tapped at 43% and utilize 100K grid resistors....

Tell him cheap chinese Valve Arts last 4000 to 5000 hours in these same amps.

I wouldn't mention me too much if at all. Jim and I are not best freinds to say the least. We've had more then one run in on internet forums about his claims about various modern production tubes.

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  • 2 weeks later...
  • 2 months later...

Well, I haven't tried then in my VRD, but have tried then in my MC275. I think the most important thing is to break then in, I know I was a little apprehensive to start about this entire break in thing. They suggest break in for the Shuguang Treasures KT-88, Grade A is 300 hours, well I have got about 400 hours on mine and they do sound real good, better than the Gold Lion, there seems to be a lot better sound stage and imaging, one way I judge then I still am hearing things I have heard before on my go to CD's. I will have to admit that there were times that between 100 and 200 hours that these were terrible and you could hardly stand to listen to then, but as hours progressed they just got better and better. I like them so well I believe I will get another matched quad of the Grade A as backup or for the VRD's

Just a note, you can get them a lot cheaper if you go to some suppliers in China.

Just my 2 cents guys.

Cigarbum

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  • 3 months later...

Sure go for it. The only real difference that could cause a problem in some amplifiers is the 120's draw more heater current then any other tube with the same pin out. But that is not a problem in my amps I over spec everything. The problem you may have is the 120 is designed to be run real hard compared to a KT-88 and may not sound its best in an amp designed to run modern KT88's in a comfortable electrical environment. I've yet to try a set of those tubes so your venturing into unknown territory.

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The Penta KT88-98 is not the same tube as the Shugaung KT88-98. The Penta KT88-98 actually is what Shugaung calls the KT-100.....(and no it is not the same as the Valve Art KT-100)

OOOOHHHH.....ooooookay, that KT100 is the "flat topped" one with the dual side and top getter with the rectangle supports on the top micas, right? I do recall that tube. I never did try that one...seemed to me the reviews of that tube weren't so hot. Seems I have had several tell me here to avoid that one, but can't attribute it to anyone in particular from memory.

Dave,

Sorry I missed this post of yours... You got it exactly right. Some folks just don't seem to realize that Shuguang will name a tube for the vendor buying thousands anything they desire. And many many vendors exist that utilize the Shuguang service. Most of them opt to use the basic Shuguang KT-88-98... Valve Art and Ruby for instance. Penta chose to use the GEKKT88 the truest reproduction of the Genelax on the market today IMHO.... The Shuguang factory purchased the tooling when the MOV (Genelax) plant closed in England. Of course the Chinese do what they are famous for and do not build it out of absolute identical components or quality. But it is indeed a real nice KT-88 as modern production tubes go...

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  • 1 month later...

Hello,

New to this forum. Craig (NOS Valves) posted some good information on another website, so I decided to get involved over here.

Looking for some more feedback on the Black Treasure KT88 vs. Penta KT88SC. I have a quad of both. My amp (Eastern Electric M88) came with the Black Treasures (which do sound excellent) I got a quad of Penta KT88SC from Doug's Tubes as a backup. At first, they were somewhat harsher than the Black Treasures, but they are getting much better as they continue to break in. The prices for a spare quad of the Black Treasures is a bit high. I did see some for sale on Ebay, but if you look at the pics and ask questions, the test results are all low/suspect (30-36ma).

Craig, was wondering if you had any additional information to share on this? Do you still think that the Black Treasures are just a KT88-98 with carbon coated plates and glass? Does that alone really make a difference? I know in the 50s a fair number of tubes had the black coating inside.

BTW, I also had a lot of trouble with the Gold Lion re-issue tubes. I had no less than six go bad in short order. They also comsumed flashing at an alarming rate.

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