6H13C instead of 6AS7G

Re: 6H13C instead of 6AS7G, posted on October 31, 2004 at 06:02:01
LineArrayNut Audiophile Posts: 1953 Location: Tenn. Joined: December 10, 2002	IMHO they're all the same; I thought the " OTK " meant they had been mil-spec, any one care to comment? My Svetlana Real flying =C= brand look EXACTLY like the Sovteks I have, BTW.

Re: 6H13C instead of 6AS7G, posted on October 31, 2004 at 07:42:25

Legendre
Audiophile

Posts: 503
Location: Saint Paul
Joined: October 22, 2004

As I understand it, the Russians never made a 'true' 6AS7G.. the 6H13C (6N13S in latin script) is a ruggedized, work-alike variant. This is the only tube we have ever shipped with Atma-Sphere equipment; the American 6AS7G/6AS7GA/6080 are not suitable for use in our equipment. No real loss, as the American tubes (at least the 6AS7G) are much less available than the 6H13C.

There were two primary sources of production - Svetlana plant in St. Petersburg, and Reflector plant in Saratov. The OTK stamp is a Russian Army quality marking, basically meaning 'suitable for use'. There is some belief that the higher the OTK stamp number, the higher the quality - but I am unable to confirm this. Initially, the 6H13C branded 'Sovtek' were made at Reflector, but I have seen so much mix-and-match over the years, that the distinction is being lost. We have also seen tubes with American or European branding that were actually just re-marked Russian tubes. Check the shape of the base & glass, it's a dead giveaway.

So, it goes like this:

If it has a =C= logo *anywhere* on the glass, it's a Svetlana tube.
No =C= logo, it's a Reflector tube.

In our experience, the Svetlana is the preferred device.

Bill

Svetlana - would you say more about this?, posted on October 31, 2004 at 13:10:51
Rushton Reviewer Posts: 726 Location: Huntsville, AL Joined: January 5, 2001 Contributor Since: October 23, 2004	Bill, would you mind elaborating on your comment: "In our experience, the Svetlana is the preferred device." I've always been curious about why to choose Svetlana versus Sovtek, and I've never heard an explanaton from someone with your experience with these tubes. When I asked Ralph a number of years ago, he didn't seem to have much of an opinion (at least not one he was expressing).

Re: Svetlana - would you say more about this?, posted on October 31, 2004 at 13:51:47
LineArrayNut Audiophile Posts: 1953 Location: Tenn. Joined: December 10, 2002	I bought svetlana flying =C= from Atma 2 yrs ago and they are EXACTLY down to the last detail the same as the Sovteks that I had already in my used M-60MkII.2's and sounded absolutely the same, just my humble opinion...

Re: Svetlana - would you say more about this?, posted on October 31, 2004 at 18:07:49

Rod M
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Posts: 16246
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Joined: March 1, 1999
Contributor
Since: March 1, 1999

Sound and reliability are the two issues. When I got my S-30, it came with an extra tube. Sure enough, one of the Sovtek's was questionable and one channel wouldn't bias with it. I picked up a replacement set of Svetlanas along the line and they were all perfect and might sound a tiny, tiny bit better. Construction wise, they do look the same, right down to a sticker that I can't read without my glasses on the top.

Re: Svetlana - would you say more about this?, posted on November 1, 2004 at 07:56:27

Legendre
Audiophile

Posts: 503
Location: Saint Paul
Joined: October 22, 2004

Hi Rush,

If the Svetlana tube is 'preferred', it's certainly not an issue of sonics. As at least one other poster pointed out, there is no discernable difference in sound between the Svetlana / Reflector plant tubes. Also noted, the tubes appear to be internally identical - I don't doubt that they are made on identical sets of tooling. Assuming the same materials, we are left with the human factor, so..

The preference is mostly related to quality of service. As things have played out over the years, we've just found that we've had better luck with the Svetlana tubes, in terms of resistance to arc-over and shipping damage, etc. Add to this the fact that during the Soviet era, Svetlana was considered the 'premier' tube manufacturer, and the Svetlana devices just seem to come out ahead. The current stock of Svetlana tubes we own has been generally regarded (in-house) as the best we've ever seen.

Hope this helps to clear up the question.

Bill

Re: Svetlana - would you say more about this?, posted on November 1, 2004 at 09:36:40
LineArrayNut Audiophile Posts: 1953 Location: Tenn. Joined: December 10, 2002	Bill, Thanks for the screws for my M-60's; I sent a fiver with a note to the adress you provided when I called, (my bill was $3, as you may recall). No word back from them as yet, LOL! Regards, Jack

Screws, posted on November 1, 2004 at 15:05:20

Legendre
Audiophile

Posts: 503
Location: Saint Paul
Joined: October 22, 2004

Jack,

Glad to hear they got there; hope they help you out. I sent a few extra, as you might have noticed.

Bill

Thanks to all who offered information on this. (nt), posted on November 1, 2004 at 15:55:03
Rushton Reviewer Posts: 726 Location: Huntsville, AL Joined: January 5, 2001 Contributor Since: October 23, 2004

yes sir, I appreciate it! Thanks again! (nt), posted on November 1, 2004 at 16:40:25
LineArrayNut Audiophile Posts: 1953 Location: Tenn. Joined: December 10, 2002	.

Re: Svetlana - would you say more about this?, posted on November 1, 2004 at 23:00:37

TerryC
Audiophile

Posts: 31
Joined: November 1, 2004

So you're saying the extra 30% in price (Sovtek @$18 vs. Svetlana @$24 from Atma-Sphere) does not get a tube that sounds better, but one that is just less likely to fail or break?

A few months ago I tried to get Svetlanas from a local supplier in Canada who deals with New Sensor. They sent him Sovteks. Apparently there has been a change in distribution. The Svetlana (flying C) distribution does not seem to be importing the 6AS7. So the only supplier of new Svetlana 6SN7 is Atma-Sphere. Does anyone know otherwise?

To further muddy the waters.., posted on November 2, 2004 at 08:09:52

Legendre
Audiophile

Posts: 503
Location: Saint Paul
Joined: October 22, 2004

I was checking a set of tubes for an MA-1 yesterday. These tubes all had the Sovtek name & logo screened on the glass - next to an *etched* Svetlana =C= logo(!) This is the large =C= logo, with 6H13C printed inside the C.

But to confirm: our preference for Svetlana tubes is not based on sonics.. just quality of service. We sell Sovtek/Reflector as well, when we have them in stock. Use whichever you like, and as you develop your own opinions on the merits/failings of the two devices, please share them with the rest of us.

Bill

Re: To further muddy the waters.., posted on November 2, 2004 at 10:13:38

pathologymd

OK, let's muddy the waters even more! I bought ten or so Svetlana 6AS7's from Ralph about a year ago, and the tubes I received came in yellow and blue boxes marked "made in USSR." The tubes themselves have no logo whatsoever, and say "6AS7G Made in USSR." I paid the Svetlana price, but not sure what I got!

William

Re: To further muddy the waters.., posted on November 2, 2004 at 11:43:06
TerryC Audiophile Posts: 31 Joined: November 1, 2004	Even less reason for paying the extra $6. Also, I have seen it implied on internet sites that the distributor who once sold Svetlana tubes and still owns the Svetlana name, has put this name on tubes not made by Svetlana.

Re: 6H13C instead of 6AS7G, my experiment, posted on November 8, 2004 at 06:22:04

Cousin Billy
Manufacturer

Posts: 243
Location: Greater Toronto Area
Joined: September 10, 2004

I now have a number of these different variations. One set of Sovteks doesn't have the flying =C=, one set does. The rest of the tubes all have the =C=. Obviously the one set of Sovteks with the =C= are rebranded Svet's.

I put my heaviest tubes in one MA1 Silver, OTK 74-76's (yes, one set of tubes is physically heavier than the others, don't argue, the scale does not lie) and I put my non =C= Sovteks in the other amp.

Here is my first observation.
There appeared to be a slight shift of balance to the side with the =C='s. I then turned everything off, and switched the 6H13C's, obviously leaving the 6SN7's. This balance abnomoly followed the tubes. Everything moved slightly towards the speaker with the =C='s. This may be explained by my second observation.

My second observation is more important.
When I went really close to the =C='s tweeter, there was slightly more extension in the upper frequencies, I could hear more of the music. Female voices especially showed this extension, with ever so slightly more articulate, everything was more focused. It is this high frequency improvement that makes me only want higher numbered OTK Svetlana's.

The differences where sutle, but they where there. To my ears anyway.

Bill

OTL Asylum

6H13C instead of 6AS7G

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