[gregb]

And further to my last past I was told that these are the ones not to buy. They don't sound as nice and don't last as long. Maybe Morzh can enlighten me as to what the difference would be between them.

http://www.ebay.com/itm/PLATINUM-Matched...SwGzlTu6zY

Gregb

[morzh]

Greg

The former, if indeed new, by their marking seem to be mil grade Soviet ones which were always good. They would come of the same production line as the rest of them but would be held to a higher standard. The other tubes could be as good but were not tested to these standards.

The latter are not Soviet, they are Russian and are supposed to be good tubes, but as their manufacturing was stopped for over 30 years, they are probably not exactly the same. Maybe better. Maybe not.

Personally, I bought mil grade Mullards for my Mac. The best Soviet tubes, however good, never bested Western manufactured ones.

And, this said, I am honestly not sure I would be able to hear the difference.

[gregb]

Good to know, Thank you. I have both these tubes and some RCA 7189's and I truly can't hear a difference but they both sound good to me.

Gregb

[Arran]

And further to my last past I was told that these are the ones not to buy. They don't sound as nice and don't last as long. Maybe Morzh can enlighten me as to what the difference would be between them.

http://www.ebay.com/itm/PLATINUM-Matched...SwGzlTu6zY

 The listing says that they are made by Reflector, which is the same company that makes Sovtek branded tubes, just older stock is all. I don't know why they say that there is anything wrong with them as opposed to the Sovtek ones. I believe that the mill spec tested ones have a pentagon shaped logo on the glass that says "CCCP" inside, as Mike says that just means that the tube got a passing grade for military use. So lets say they needed 500 5U4s, so they tested as many tubes as they needed off the line until to meet the quota, but that doesn't mean that the other 1000 5U4s they made that day were junk. I'm just taking a guess about how they did things since this was pretty much how the U.S or Canadian military did things, like with JAN numbered tubes for example where they say VTXXX.
Regards
Arran
Regards
Arran

[Arran]

...I already have some spare Chinese 6E2 (replacement for 6FG6/EM84...

Ron;
  Here is one the Soviet versions of the China 6E2/EM84, I cannot vouch for the quality nor the seller. There also seems to be a lot of Soviet EM80s for sale as well, no good when the set I have uses an EM81.

http://www.ebay.com/itm/6E3P-6FG6-EM84-M...SwZd1VcL6W

Regards
Arran

[Ron Ramirez]

http://www.ebay.com/itm/331889502128

For a few dollars more ($79.50), one may purchase a new set of matched quad Sovtek EL84M tubes from Jim McShane.

http://mcshanedesign.net/tubes.htm

Is there a difference between 6П14П, 6П14П-K, 6П14П-EB and 6П14П-EP? The set I bought (from a USA seller) only say 6П14П and were built during the Soviet era.

[Ron Ramirez]

In talking with a few different audio guys in the past they say best of the Russian output tubes are the ones in the link below...
http://www.ebay.com/itm/332035931912

Thanks, Greg - much appreciated - I'll keep those in mind.

[Ron Ramirez]

Here is one the Soviet versions of the China 6E2/EM84...

http://www.ebay.com/itm/331882073096

Thanks Arran. With the Chinese 6E2s I bought, I should be in good shape on these for awhile.

BTW, guys, here's a link to the used, tested 6П14П tubes that I bought:

http://www.ebay.com/itm/292071719842

P.S. Mike (morzh), where did you get your Mullards for your Mac? Didn't you get yours from Jim McShane?

[morzh]

I believe that the mill spec tested ones have a pentagon shaped logo on the glass that says "CCCP" inside,

Arran,
No, the Pentagon with СССР and some lines inside is the Soviet "Quality Mark", was put on the consumer goods, not military.
The military, such as the tube I wrote about on eBay, have a diamond with some number inside.




Ron,

yes, from Jim McShane. He came recommended through the, I think, Audiokarma, and we wrote to each other, and I liked the guy. The tubes came with original packaging which is your typical military overkill: you could run an Abrahams tank over it and it would survive. Plus the pins have that plastic thing that goes over them so they do not get bent.....UK military were sure particular about their tubes.

[Ron Ramirez]

The tubes are slowly rolling in...

[Image: http://www.philcoradio.com/images/phorum...00_007.jpg]

Two Raytheon 6AQ8/ECC85 (made in Japan), one Siemens ECH81/6AJ8 (Germany - not pictured), one Sovtek 5AR4/GZ34 (Russia) and four 6П14П (Soviet Union). Still waiting for a 6AU6 from California.

Unfortunately, one of the 6П14П tubes did not survive shipment - it isn't broken, but the filament is intermittent. When I put it on my tube tester's Line Test, I can watch the needle go back and forth as the filament goes on and off. I've contacted the seller and hope to receive a replacement.

In the meantime...Greg, you will be glad to know that I purchased four 6П14П-EB tubes from the seller you receommended, in Ukraine. I did so in case the 6П14П tubes I now have do not work out for some reason, although three of the four tested quite strong and I think the seller will probably give me another with no hassles.

Now...I have to get my electrolytic info together and contact Hayseed Hamfest for a quote on three twist-lock electrolytic cans.

[gregb]

Good to hear Ron, I know mine were slow to arrive but they always show up and I have ordered a fair number of them.

Gregb

[Ron Ramirez]

Greg

The Ukraine seller has less than stellar feedback, which made me a bit hesitant at first, but I proceeded with the order upon your recommendation. If you're happy with the seller, then he must be OK.

Having ordered a few things from China and now knowing how long it takes for items to go through customs...no, I don't expect the tubes to get here from Ukraine tomorrow. I don't expect to see them until maybe a month from now. If they arrive sooner than that...well, that's just a bonus.

Oh, by the way...request for quote sent to Hayseed Hamfest. We shall see...

[Arran]

No, the Pentagon with СССР and some lines inside is the Soviet "Quality Mark", was put on the consumer goods, not military.
The military, such as the tube I wrote about on eBay, have a diamond with some number inside.

Mike;
  I see the diamond mark, and it also has an "OTK" mark next to it. Personally I think that seller's prices are rather high, mil spec or not, Soviet/Russian EL84s are all over the place, and still being made, also Western made NOS EL84s are also not too hard to find.
  Given my experience with EL84s I would not want to build a home made amp using them, and I think that anyone wanting to manufacture new amps using the same is crazy. Whilst they do work they also run extremely hot since a 6BQ5/EL84 is basically a 6V6GT stuffed into a mini nine pin envelope, and the way some newer audio amps are designed they drive them to the limit which further shortens their life. In the case of this Fisher TA-600, it's a restoration so I would use whatever the factory used, unlike some of the companies building amps today they probably operated the tubes withing recommended specs anyhow. However if I were to build a home brew amp I would use 6V6GTs, or possibly 6K6GTs, both were used as vertical output amplifiers in B&W TVs back in the 1950s, same with 25L6GTs, so there are more good used and NOS ones around then anyone could ever use.
Regards
Arran

[morzh]

OTK, Btw, stands for Otdel Tekhnicheskogo Kontrolya - the Department of Quality Control, QC.

[Ron Ramirez]

Another tube arrived today, a 6AU6WC military Sylvania.

So this evening I decided to try an experiment.

Not having a full set of 6П14П tubes yet, I reinstalled the original very weak 7189 Fisher tubes, hooked up a pair of speakers, and put the TA-600 on the Variac.

By 90 volts I could see the FM tuning eye (I had it set to FM), and I was obviously tuning in stations as the eye was opening and closing as I tuned across the FM band. So by visual indication, the tuner appears to be OK. I did switch it to AM and also saw the AM tuning eye opening and closing as I tuned across the AM band, though not as much as on FM.

One problem though.

No music...no talking...no noise...nothing.

Silent Night.

Or, if you prefer, The Sounds of Silence.

???

I turned the Variac off and unplugged everything. The 5AR4/GZ34 was barely lukewarm, and the 7189s were cold.

Hmmm...sounded like no B+ to the output tubes to me.

Consulting the schematic (yes, I'll post a copy later, perhaps tomorrow), I noticed that there is a 160 ohm, 10 watt resistor between the 5AR4/GZ34 cathode and the input electrolytic capacitor section.

You guessed it...that resistor is open.

I won't be doing any more Variac tests until after I replace the electrolytics and, of course, that burned out resistor. I'll also check the other power resistors to see if any others are open.

Back to the 6П14П...the seller readily agreed to send me a replacement, and I noticed today that it indeed has been sent as I received the notification from USPS.

I have my price quote from Hayseed Hamfest also, and the cost will be about what I expected it to be.

So this weekend, I need to order the loose electrolytics along with one or more power resistors from Mouser, and get the order going for the new twist-lock cans from Hayseed Hamfest. Yes, I could cut open the original cans and restuff them, but this is a special unit and it deserves the special treatment of new twist-lock electrolytics.