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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. triggsviola
    This is kind of joke. It doesn’t actually work. I ordered two Mullard EL38s for my Euforia but, through a computer error, only one came, so I decided to put it in my Vali. 6922 socket saver -> 6SN7 adapter -> EL38 adapter -> EL38 tube. Lots of noise and only one channel works. This tube is not meant to be a driver tube. It’s meant to be a power tube as part of pair. I don’t think I damaged my amp because it works fine after putting my 6SN7 back. Maybe I destroyed the tube. I won’t know for another month when the other Mullard comes in. It’s a good 8 inches tall.
     
    Old Deaf Donkey likes this.
  2. Old Deaf Donkey
    Oh, Donkey...
     
  3. bcowen
    It's fortunate you didn't fry your Vali. An EL-38 pulls 1.4 amps of heater current. The Vali 2 is designed for a 6922 that pulls 300 milliamps. Lots of folks run tubes that pull 600 milliamps (like me) -- 6SN7's, etc. that the Vali handles without issue, but 1.4 amps? Ouch. The EL-38 also draws 95 milliamps of anode current versus the 15 milliamps of a 6922 or 10 milliamps of a 6SN7. Count your blessings, but if it were me I certainly wouldn't fire it up like that again.
     
    KoshNaranek likes this.
  4. ScubaMan2017
    I heard about this on the other thread. Last time I cyber-chatted with him, he was at the dentist getting some dental work (1.5 weeks back). @Ripper2860 , I appreciated the update.
     
    bcowen likes this.
  5. bcowen
    The Foton 6N8S (6SN7) Experiment, Part 2.

    As a refresher, I matched up two '58 Fotons with smooth plates and two '52's with ribbed plates. I selected ones where both triodes matched up very closely on my Hickok -- almost identically, and where all 4 tubes matched up very closely as well. I sucked out and replaced the solder in one of the '58's and one of the '52's, and left the other two untouched from the factory soldering job. Once that was done I gave all four tubes 5 hours of play time in my Cary preamp just to get over any initial sonic changes. Sooooooo…..after listening, both the '52 and the '58 with factory solder sounded rather spitty in the treble, were somewhat fatiguing, and lacked slam and impact in the mid and upper bass as well as curtailed bass extension. The '52 and '58 with the solder replaced? Both sounded great right off the bat. With only 5 hours time, they both sounded like a Foton after 100 hours of play time. I put the '52 and '58 with the factory solder back in the Cary and gave them an additional 100 hours of play time. Stuck 'em in the Lyr, and guess what? Both sounded great. Sounded like Fotons with 100+ hours of play time. :relaxed: So although this may not be an entirely scientific test, I think it's reasonable objective proof that the long, roller-coaster break-in ride generally ascribed to these particular Fotons has been due -- in part or in full -- to the crappy (or perhaps degraded) factory soldering job as @Paladin79 first suggested.

    Now here's the interesting part: from everything I've read and seen reported by others (including my own opinion), the ribbed plate versions ('56 and earlier) sound better than the smooth plate versions ('57 and later). With the solder replaced, I can't tell any real difference between them. Honestly. In fact, were Tom to put a '52 and a '58 in PVC tubes, I wouldn't be betting any steak dinner on my ability to tell which was which. If there are any differences, they are extremely minor at best. The factory soldering job on the ribbed plate tubes looks much better than the soldering on the smooth plate '58's....perhaps the belief that the ribbed plates sound better is simply due to a better factory soldering job (at least visually) on the earlier tubes?

    But I'm not done yet. My personal opinion is that any of the '50's tubes (ribbed or smooth plate) sound better than the '60's versions. If you look very closely, the internal construction is identical other than the plate formation. The '60's tubes I have in my possession have the same visually crappy soldering job as the '58's. Maybe the '60's sound just as good once the solder is replaced? So I'm in the process of matching up some '61's....one I'll replace the solder in and the other I'll leave untouched and go through the same routine with them. Stay tuned for Part 3. :sweat_smile:


    '52 on the left, '61 on the right:

    52 and 61 Fotons.jpg

    '52 factory solder:

    52 Foton.jpg

    '58 factory solder:

    58 Foton.jpg

    '61 factory solder:

    61 Foton.jpg
     
  6. Paladin79
    I just got some ribbed plate 53’s but I have had no time to change the solder yet. It is great to know that any 50’s Foton can be a nice find, I had a 1954 in the batch I sent Jason.
     
    bcowen likes this.
  7. bcowen
    Hope you re-did the pins on that one you sent Jason. :relaxed:

    The ribbed plate versions have all but disappeared from Ebay, but there are currently several ads for '58's at decent prices. And lots of ads for '60's production at very cheap prices. I'm real interested to see how the '60's fare after redoing the pins. I have some '60's, '61's, '62's and '65's to play with.
     
    TK16 and Paladin79 like this.
  8. Paladin79
    I did, there was no way I was going to run it for 100 hours lol
     
    bcowen likes this.
  9. Ripper2860
    Imagine how much better it would have fared if you had... :smirk:
     
    bcowen likes this.
  10. Paladin79
    You may want to read up, that myth has been dispelled.

    After 100 hours the tube just has less life on it.
     
    Last edited: Sep 15, 2019
    bcowen likes this.
  11. Mr Trev
    You do realize the '63 and '64 are the cream of the crop:smiling_imp:

    <edit> you showed before pics. why no after? let's see your handy work
     
    Last edited: Sep 15, 2019
    bcowen likes this.
  12. Ripper2860

    3 words...

    Tube Death Rally. :stuck_out_tongue:

    Also - The research has not been independently verified or submitted and validated via peer review. :smirk:

    **Note: When I use an emoticon it typically means that I'm kidding. :wink:
     
    Last edited: Sep 15, 2019
    TK16 and bcowen like this.
  13. Paladin79

    It is a little hard to know what you have or have not read. I was just pointing out recent info.
     
    Ripper2860 and bcowen like this.
  14. bcowen
    I'm just happy to finally know that he can actually read. :relaxed:
     
    TK16 likes this.
  15. bcowen
    Always gotta be someone here from Missouri. :stuck_out_tongue:

    The '58 below. The '52 is currently in the Lyr 3 playing this, and it ain't coming out. For this kind of music, the Foton kicks the Frankie out of the socket...

    upload_2019-9-15_16-18-42.png

    58 Resoldered.jpg
     
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