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Are These Authentic Russian Military 1578 Vacuum Tubes?

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All that octal tubes were fair copies of early RCA tubes, when RCA was in zenith. It happened during WW-II, when our fathers were allies and fought together against technologically superior Germany. Red Army used as well borrowed from U.S Army electronics and supplied parts for it. Tubes even had the same names, until during Cold War Khrushchev commanded to ban "Names of potential enemy" and rename all tubes in Cyrillic. Like, 6N7 to 6H7C, 6SN7 to 6H8C, 6SL7 to 6H9C. But at that time new tubes become available for military, like Gu-50, 4P1L and other Loctal types based on German prototypes. Also, miniature tubes were developed for missiles and other similar applications, like 6N16B, 6N17B, 6J5B, and so on. 6N16B were replacing 6SN7 in miniature equipment, 6N17B were replacing 6SL7.

I will agree that the Russian tubes are somewhat similar to what we have here and I will site the 807 as a classic example. I will disagree that the 6SN7 and 6SL7 were copied. All one has to do is look at the internal structure and see that the plate size and shape are not the same. Sure they had a tube similar to what we had and if needed they could pop one of ours into their equipment. The quality nose wise is quite a different story to me as theirs is a lot more quiet in the same setting. In my Dynaco Stereo 70 I made a driver board that I use a 6SN7 input and 6SL7 phase splitter for each channel. No matter what I put in for american tubes I end up with a slight hum and when I switch to russian tubes its absolutely dead quiet. Getting back to the internal structure of the tube all you have to do is look inside the russian tube and the american tube and see that the plate design/structure is different. The 807's that I have seen are almost a 100% copy. So 6SN7 6Sl7 will work yes a copy I don't think so. Do basically the same thing yes. But this is just my opinion based on what I see when I look inside the tubes and in my opinion a tube can be made designed and do the same basic thing without being a 100% copy.
 
Of course, both Russian and American tubes had been constantly redesigned since 1940'th, and re-design went to different directions. For example, when some another Russian plant started manufacturing the same tubes they usually tried to adjust construction a little bit to already existing equipment and materials, to manufacture tubes in specs, but cheaper than if everything had to be copied exactly.
 
I am thinking the "1578" thing is just a selection process for the best tubes.

Here are some grey plate 6H8C with 1578 stamped on them, EXACTLY the same as the original tubes I posted about.

This at least proves a 1578 can be different tubes, and Burnedfingers, I think you may be wrong.... these aren't even listed as "1578" even though it is stamped on them so I doubt they are fakes.

MATCHED PAIR 6N8S 6H8C / 6SN7 metal base HOLE PLATE UNUSED | eBay
 
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I'm wondering what the score is with the 1578, I had understood that at least at some point in time it was a unique type, perhaps later on the different designations were merged for premium versions.. Wavebourne can you clarify? I totally don't trust my memory on this one, but I thought I had seen some with just the "1578" marking on them.
 
I am thinking the "1578" thing is just a selection process for the best tubes.

Here are some grey plate 6H8C with 1578 stamped on them, EXACTLY the same as the original tubes I posted about.

This at least proves a 1578 can be different tubes, and Burnedfingers, I think you may be wrong.... these aren't even listed as "1578" even though it is stamped on them so I doubt they are fakes.

MATCHED PAIR 6N8S 6H8C / 6SN7 metal base HOLE PLATE UNUSED | eBay

These look to me like someone attempted to make them appear to be 1578's The 1578 and the box around them is smeared. Mine have a slightly different 1578 marking. The marking on my tubes is very clear and sharp in appearance.
 
I have genuine NOS 1578, and they are the finest 6SN7 type I have ever tried. The ones on EBay have similar internal construction to the 1578's, but without seeing one in the flesh its hard to tell if they are identical.

This is the genuine article:

1578.jpg
 
An interesting bit of trivia on these tubes is that the actual 1578's were used in Russian Mig jet fighter aircraft and in nuclear power stations. They were built to the highest standard possible at that stage.

In terms of sound quality, they are the most revealing of all the 6SN7 variants including Sylvania & RCA as well the newer Shuguang Black Treasure CV-181. However, they provide this extra mid range detail with an extra touch of sweetness than the other NOS tubes, which will sound a bit "off" in direct comparison. They also articulate bass very well indeed and seem to have the best balance in this area as well.

Unfortunately they are very rare, but if you get a hold of them, they will last a very long time.
 
Looks like construction is identical for all the metal base/hole plate 6H8Cs to me, except some have grey and some have black plates, but now I have seen both with 1578 printed on the glass. I think the "1578" marking may have just been for tubes that meet certain performance criteria, because otherwise they have exactly the same 6H8C markings as the tubes that do not have 1578 printed on them.
 
I have genuine NOS 1578, and they are the finest 6SN7 type I have ever tried. The ones on EBay have similar internal construction to the 1578's, but without seeing one in the flesh its hard to tell if they are identical.

This is the genuine article:

http://i668.photobucket.com/albums/vv49/tp1_2009/1578.jpg?t=
1349117373

I can say the exact same thing. They are the finest 6SN7 around. Beware of all the fakes out there. The 1578 logo is always sharp and clean. You can see the pictures I posted of the real 1578's. If your willing to take the chance then purchase the questionable tubes on ebay. I have had the opportunity to see and handle 50 of these tubes in the past and all of them have the same color plates and same construction....not similar. But what do I know? I just happen to have the real thing.:)
 
So 1578s have EXACTLY the same "6H8C" markings, yet somehow they are magically different?

The ebay seller didn't even put "1578" in the title of the auction, which means it's not even searchable as a 1578. I'm sure he would go through the effort to counterfeit the marking, then not even list it as a 1578 on ebay?

Good point - they do look like the real thing. The ones I have just look newer I guess. Could be worth a try if there is a return policy if not satisfied. I have been burnt before while getting these for my pre and power amps. A couple simply didn't work in my amps - buzzing and all sorts of noises. The ones I bought as genuine NOS from the Tubestore before they sold out were (and are) absolutely perfect.

Also be wary of these 1578's - they seem to work OK but nothing like the real thing and not even up to the standard of Full Music 6sN7 IMO.

2 x RARE OLDEST 1578 6N8S 6SN7 Metal base MELZ 1950s | eBay
 
Good point - they do look like the real thing. The ones I have just look newer I guess. Could be worth a try if there is a return policy if not satisfied. I have been burnt before while getting these for my pre and power amps. A couple simply didn't work in my amps - buzzing and all sorts of noises. The ones I bought as genuine NOS from the Tubestore before they sold out were (and are) absolutely perfect.

Also be wary of these 1578's - they seem to work OK but nothing like the real thing and not even up to the standard of Full Music 6sN7 IMO.

2 x RARE OLDEST 1578 6N8S 6SN7 Metal base MELZ 1950s | eBay

Oh well, I just picked up a pair for $20. At that price it's ok... I have a few regular 6H8Cs as well and I like them as output tubes in my Aikido, they are less noisy than others I've tried.

There is another seller with black plate tubes and 10+ pair available...

6N8S = 6SN7 tubes Metal base 1578 MELZ QTY=2 | eBay
 
Melz 1578 Tube

I have tryed to buy the Melz Tube by the russian web site rutubes.com

I havent recieved the tube , neither they give me a track&trace number . I wrote a mail with questions about this tube no answer ;-(
Got money back from PayPal but anyway .

Can anyone here tell me where to buy them ?

Regards Torben
 
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