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NOS 572b vs. chinese remake

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ubuntupokemoninc

Sat Dec 18 2010, 08:15PM

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I realize the nos 811a is better, because the Chinese remake sucks, for the the 811a's replacement the 572b, is it really worth the extra $ for a nos?

Steve Conner

Sat Dec 18 2010, 08:18PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
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Only on Ebay could Svetlana tubes be called NOS. They're Russian, made in the 1990s.

But as far as I know they are considerably better quality than the Chinese tubes. If it were me I'd get the Svetlanas. Unless it's your first VTTC or something, and you think you might trash them anyway.

ubuntupokemoninc

Sat Dec 18 2010, 08:30PM

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thanks

Proud Mary

Sat Dec 18 2010, 08:39PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
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Steve McConner wrote ...

Only on Ebay could Svetlana tubes be called NOS. They're Russian, made in the 1990s.

But as far as I know they are considerably better quality than the Chinese tubes. If it were me I'd get the Svetlanas. Unless it's your first VTTC or something, and you think you might trash them anyway.

Not so fast, Capeless Crusader! Svetlana resurrected their 572B design, and even wrote an English language data sheet for it in 2003, to capitalize on the emergent audiophile 'tube' market. So they might even be called New Old New Stock -

The datasheet writer clearly came from a promotional background: The titanium coating covers the entire anode area extended by
the inherent micro surface roughness of graphite.

I'd have gone further myself: The exquisitely crafted titanium coating covers the entire intimate anode area extended by the shamelessy seductive micro surface roughness of graphite. But there's no accounting for bad taste, I suppose.

U4R1A

Sat Dec 18 2010, 08:41PM

Registered Member #3505 Joined: Sun Dec 12 2010, 06:03AM
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I just bought a pair of matched Chinese 811a's($32) off ebay mainly because its my first VTTC and I plan on pushing the madness a little but I haven't seen any true 572b's on ebay only the Chinese 572b's and they were around 50-70 bucks.

ubuntupokemoninc

Sat Dec 18 2010, 09:04PM

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the Chinese 811a i bout never worked!

Steve Conner

Sat Dec 18 2010, 09:12PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
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We have NOS, UOS, NONS, so I propose O NOES (Old New Over-Expensive Stock)

I thought the Chinese tubes were designed with the audiophile market in mind. Audio amps run the tubes at lower voltages than a RF amplifier or VTTC would, so I wouldn't be surprised if they cut corners in the tube manufacture to take advantage of that.

ubuntupokemoninc

Sat Dec 18 2010, 09:24PM

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both 811a's from china had grid to filimet shorts,

will the russian 572b fit in the 811a base

my vttc never worked with the chinese, why would both tubes be damaged?

Weston

Sun Dec 19 2010, 12:42AM

Registered Member #1316 Joined: Thu Feb 14 2008, 03:35AM
Location: Cambridge, MA
Posts: 365

The svetlana 582b's fit in the standard 811a socket. I have one for my vttc experiments and it is hard to kill. However it's grid is on the small size and most of my coils end up driving the rid to red heat.

One thing to watch out for is due to the light colored anode it is hard to see when it is red when the filament is on. You really have no indication you are overheating the poor tube when the coil is running.

Despite being great tubes their price makes then not justified in a vttc. Get a 833 or some taylor branded 811a's from rf parts. They come with a warranty and countless people have used them in vetch's.

ubuntupokemoninc

Sun Dec 19 2010, 01:03AM

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i would love to see a vid of it running

heck a gu-5b is $5 cheaper, should I go with that, will gu-5b work in the US with 60hz on the filiment?

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