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Vali 2 tube rolling

Discussion in 'Headphone Amps (full-size)' started by capt369, Jan 8, 2016.
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  1. Paladin79
    I am building some amps using 6sn7's and 6as7G's, in doing some research I can recall one engineer saying he preferred octals to miniatures because of the larger cathodes and anodes. They provide more airiness and presence in his opinion. That may well be my problem when trying to use 12At7's and such, I just prefer the octals. The amps will also run 6sl7's so a local group of friends and I may do some blind testing with those down the road as well.
    bcowen and Old Deaf Donkey like this.
  2. Old Deaf Donkey
    Good luck. It is interesting to hear that my bias towards larger tubes is not just psychological but also has engineering justification.
    TK16, bcowen and Paladin79 like this.
  3. Paladin79
    Some things were done as cost savings. Is combining triodes inside a tube and shielding them better than using two tubes? Doubtful, but it saved money and saved space.
    bcowen and Old Deaf Donkey like this.
  4. Robert Padgett
    Or more importantly, that the tubes would outlive the country.
  5. bcowen
    That is really interesting. Good info! As a weird turn of events, fast forward 20 - 30 years and I have these HP's labeled as made by Amperex. They are clearly Russian made tubes, probably Reflektors with their trademark flying saucer getter. The bottle is also larger in diameter, which is normal with Soviet made 6DJ8's and 6922's. May be difficult to see in the bottom photo, but the HP/Amperex on the left is next to a true Holland made Amperex on the right. It's possible someone re-silkscreened these as an attempted fraud, but I don't think so -- the ink is very fragile and chalky and is true to the ink make-up used back in the 60's/70's (and even prior).

    Amp1.jpg Amp2.jpg Amp3.jpg
  6. TK16
    Think the double post getter was used in later tubes, I have read about Russian tubes relabled as Amperex/Philips. Not sure if HP would source Russian tubes during the Cold War.
    BTW that bad tube is my avatar, display tube online and in person.
    Last edited: Sep 8, 2019
    Old Deaf Donkey and bcowen like this.
  7. bcowen
    That makes sense. But if I were going to go to the trouble of relabeling something, I'd relabel it for something with a more highly perceived value. Why label it as an HP rather than just an Amperex? Can't ever know for sure what transpired with these, but it's a good subject for a new Nancy Drew novel. :relaxed:

    So then what you're saying is you have a bad avatar? :stuck_out_tongue:
    Old Deaf Donkey and TK16 like this.
  8. TK16
    No, avatar is extremely unbalanced and makes web browsers very noisy/micro. I can see my desk tip slightly downward with the 3x as strong Gm triode. 510 Gm on my hickok is easily the worst testing. Highest probability of getting bad tubes for me is ECC82 from Europe and Brent Jessee.
    Old Deaf Donkey likes this.
  9. Robert Padgett
    One final time-- I don't think the death of Stalin has anything to do with the quality-performance and degradation of vacuum tube solder over the years. The initial post was about the differences between 1953 vs. 1958 Fotons.

    Unlike Western Democracy, which turns over leadership on a regular two-four year cycle, the CCCP had a "strong man" leader, who died. I would be interested also in the changes within the Soviet Industry after his death.
    ODD mentioned the Collective Agriculture emphasis, but in my opinion- the Cold War loomed large during the 1950s--so emphasis Military was still quite strong.
    Were many of these vacuum tubes intended for the early electronic computers? Yes. One early Soviet computer reported used 10,000 tubes. I will also assert that workers in a Sylvania tube factory probably never anticipated that their tubes would be still working in the 21st Century.
  10. bcowen
    Do you think the workers in a Sylvania tube factory ever anticipated anything about the tubes they were making, other than if they did their jobs to the expectation(s) required they got a paycheck?
    Old Deaf Donkey and TK16 like this.
  11. Old Deaf Donkey
    Oh. I thought you did. :ksc75smile: That's unfortunate. I liked the idea: the Great Leader conks out, workers no longer afraid, stop giving a schiit about soldering as Gulag no longer looming... Here go the Fotons, and now we all have to suck the bad solder.
    ScubaMan2017, TK16 and bcowen like this.
  12. Old Deaf Donkey
    That's interesting. It has not been forbiden to buy the Soviet (or Warsaw Pact countries) tubes in the West during the Cold War - they were excessively taxed to discourage such practice. Enter grey importers as Zaerix UK. I have a pair of Zaerix branded 6J5GT sold as AEG Telefunken, with the Bundeswehr quality acceptance mark etched on the glass, but oh that flying saucer...
    Last edited: Sep 8, 2019
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  13. bcowen
    Funny how they're always flying upside down. Too much vodka on the assembly lines, I'd guess. :relaxed::laughing:
    Old Deaf Donkey and TK16 like this.
  14. Ripper2860
    What is your fascination with electronics ending in 'UNE'? Is there some hidden message to Amazon with the A-Z? :confused:
    bcowen and Old Deaf Donkey like this.
  15. Robert Padgett
    Well, The only real significant event in 1953 was Uncle Joe kicking the bucket, which may have directly caused poor Soldering skills...Let's wait until those memos are declassified:cry::money_mouth:
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