SV572-10 still being made?

[astouffer]

Is Svetlana still making the SV572 and SV811 series of tubes? I ask because the latest Stereophile features a new amp using two SV572-10 per channel SE. I thought they discontinued both types. Here is a link to the amp in question: UKD : UNISON RESEARCH S9

[FullRangeMan]

Originally Posted by astouffer

Is Svetlana still making the SV572 and SV811 series of tubes? I ask because the latest Stereophile features a new amp using two SV572-10 per channel SE. I thought they discontinued both types. Here is a link to the amp in question: UKD : UNISON RESEARCH S9

In 2009 I read on a online mag Svetlana do not made anymore the 572 line(572-b, 572-3, etc) since the 90s years.
But this is not a problem per se, because there is many thousands SV572 tubes stored in Svetlana wherehouse, military tubes have millions units waiting use in Siberia.
A problem I see is the price, as the 572 family is NOS all tube brokers rise the price in a second, the price of any 572 model I have see is always over 100 dollars each, If you can afford buy some 20 tubes to spare, maybe you would go for this amp.
Tube brokers sell/advert this tubes in small quantities to simulates they are rare etc... Iam out of this price range.
Regards, Gustavo

P.S.: Iam unaware of any SV811 info.

[kevinkr]

These types were still usually available new from New Sensor last time I checked and may be back in production if demand is sufficient. Supplies of the 572-3 tend to be spotty as it seems to have been used more frequently than the higher mu versions. (It's more linear, an important consideration in SE applications, but really hard to drive.)

[Allen Wright]

Originally Posted by FullRangeMan

... military tubes have millions units waiting use in Siberia.

Are you sure you are talking about the same tube? The original 811 and 572 tubes had top caps for transmitter usage, the SV811 and SV572 were a (mistaken?) effort to make that basic tube suitable for audio usage. As decided by the owner of the USA branch of Svetlana.

If there are millions in military storage, surely they are the top cap transmitter version?

Regards, Allen

[FullRangeMan]

Originally Posted by Allen Wright

Are you sure you are talking about the same tube? The original 811 and 572 tubes had top caps for transmitter usage, the SV811 and SV572 were a (mistaken?) effort to make that basic tube suitable for audio usage. As decided by the owner of the USA branch of Svetlana.

If there are millions in military storage, surely they are the top cap transmitter version?

Regards, Allen

Sorry, not this tube or 572 line, I was thinking in any type of vacum tube stored there.
I remember read in the meteoric FI magazine a USA tube broker(maybe Vintage Tube Service) advertising he had just bought 10 millions tubes from the USA army, then the Russian military also may have millions tubes stored somewhere.
Regards, Gustavo

[w5jag]

New Sensor still had them listed for sale last time I looked, and they turn up on Ebay fairly frequently.

I have some of the SV 811's somewhere, but they are really far down the project list. I really like the look of the transmitting tube filaments.

I don't know how many of the transmitting tube variants are still left - I haven't seen any of the Russian 811A's in quite a few years although I don't really look for them. The Svetlana 572B's are not quite the same as a regular 572B, and there are still one or two vendors selling those.

I think they were all made by Ryazan regardless of who branded them, and I'm sure someone could commission another run if they wanted them bad enough.

Win W5JAG

[FullRangeMan]

GSTUBE from Moscow yet have some 572B at 39 dollars each on its site, seems a low price compared to others shops, and Mr.Anton work very well.
''GSTube.com''. Tubes, sockets etc. Tubes.

[tubelab.com]

There seems to be some confusion as to what an SV572-10 is.

The 572B is a transmitting tube. It has been used in military and ham radio equipment for years. They were recently manufactured in China and probably elsewhere, and NOS versions are still available. It has a 4 pin base and a plate cap on the top. It is a zero bias triode with a high Mu (160?). I would believe that there stashes of these things scattered all over the world.

Svetlana corporation introduced some tubes intended for audio use about 10 years ago. The high price and uniqueness prevented their adoption by many manufacturers.

The SV572-3 has a Mu of 3 and requires a bunch of negative bias. It was intended to compete with the 845. It has a 4 pin base and no plate cap.

The SV572-10 has a Mu of 10 and requires negative bias. It was intended to compete with the 211. It has a 4 pin base and no plate cap.

The SV572-30 has a Mu of 30 and requires negative bias. It has a 4 pin base and no plate cap.

The SV572-160 has a Mu of 160 and can operate at zero bias. It has a 4 pin base and no plate cap.

NONE OF THESE TUBES ARE COMPATIBLE WITH THE 572B.

[speleo]

Ryazan still has SV811-X and SV572-X listed in their product line. Check their website here

Only parts of their web is in English but it's easy to find out what they have and how to contact them.

Cheers.

[kevinkr]

Originally Posted by speleo

Ryazan still has SV811-X and SV572-X listed in their product line. Check their website here

Only parts of their web is in English but it's easy to find out what they have and how to contact them.

Cheers.

In the United States it is simpler to just check with New Sensor, all variants of the 572-X are at least sporadically available from them as the primary importer for these tubes. I've worked on a number of commercial amps in the past that used the 572-3, and they sounded quite good, were very difficult to drive and typically lasted less than 1K hours in high power SE amp service.
You can get 25W+ out of a single tube.. (125W pd) The filaments are very fragile! (CCS heating is probably a very good idea.. )

They've gotten much more expensive in recent years, the last time I purchased 572-3 (around 1998) I paid < $65 each for these.

Svetlana Spb and formerly SED acted as distributor for a number of Ryazan tubes..