What are your favorite new production KT88 and 6550 Power Tubes?

Discussion in 'Audio Hardware' started by ThorensSme, Jan 17, 2016.

  1. IanL

    IanL Forum Resident

    Oneonta, NY USA
    I have one (of a pair) Mullard 10M 12ax7 that flashes when I turn my amp on. First time I had seen that. But so far, it does it every time. The other one right next to it does not flash.
  2. BIGGER Dave

    BIGGER Dave Forum Resident

    The reissues are not reissues. They are simply a Russian tube with a Mullard label. As far as I'm concerned, nothing more than a fake. Putting a Ferrari logo on my Corvette does not make it a Ferrari (although I wish it did).
    fortherecord likes this.
  3. ejman

    ejman Well-Known Member

    Thank you for that info. Did not know that. I dumbly assumed they were new versions with similar construction to the old Mullards...
  4. mcbrion

    mcbrion Active Member

    Like Rocky Dennis, I took am not that fond of the Gold Lions. They tend to "lean out" the sound: their mid bass qualities, in particular, diminish the sound of brass instruments in my Antique Sound Lab Hurricanes. At least, in those amps, they lack the delicacy I hear when I go to Carnegie Hall.
    I like Valve Art tubes for the Hurricanes, which is what came with them when I first bought them. I've tried many other brands, but don't like Electro Harmonix, or even the JJ Tesla (or whatever their name is): too "thick"-sounding. I'd love to have EAT tubes, but that would pay my mortgage for several months...
    Kyhl likes this.
  5. They are supposed to flash. Not sure why the other 12ax7 does not. I've heard of this happening with Mullard 12ax7's before (one not flashing), and nothing was wrong with the tube.
    IanL likes this.
  6. BIGGER Dave

    BIGGER Dave Forum Resident

    Startup flash is normal for a Mullard or Amperex 12ax7 (ecc83) tube. The flash occurs on one side of the filament wires between the bottom plate and the inside bottom of the tube. This only occurs when powering up from a cold start. The sudden influx of current on the cold heater filament encounters very little resistance along this wire and creates a sudden burst of light. So in effect one side of the tube always warms up first, the second takes a while to catch up but before long the heat is evenly distributed. If you turn off the amp and immediately restart it, you won't see the same flash if the tubes are still hot - flashing only happens on cold startup.
    SandAndGlass, Billy Budapest and IanL like this.
  7. wgallupe

    wgallupe Well-Known Member

    I have a pair of Mullard CV4003 (12AU7) as drivers in my Latino/Dynaco ST120. Both flash on start up. This is normal. Upscale Audio even mentions it on their website.
  8. ThorensSme

    ThorensSme Forum Resident Thread Starter

    Good info on the 12ax7 tube going on here, perhaps you all should start a thread on it? ;)
    IanL and nm_west like this.
  9. fortherecord

    fortherecord Forum Resident

    Upstate, NY
    I'd really like to know whether anyone has compared the Russian Tung Sol 6550 with the original. Does it sound like the original? Does it even light up like the original? These things matter.
    ThorensSme likes this.
  10. BuddhaBob

    BuddhaBob Forum Resident

    Erie, PA, USA
    Really enjoying my Gold Lion KT88s, great match for my amp which is spec'd for either KT88 or 6550. The KT88 has better imaging and tighter bass than the 6550 Sovteks that were in the amp when I got it. The quad of 88s was factory matched, from mid-2006 and I got them from my preferred seller on eBay.
    fortherecord and Hendertuckie like this.
  11. ti-triodes

    ti-triodes Forum Resident


    My favorite 6550 for a long time. I have a bunch of originals as well as some Russians. The Russians can be good to excellent to superb sounding, there's a bit of a difference in each matched quad I own. Quality control is definitely not as good as the old stuff. Old stock is generally uniform across the board and sounds smoother than the Russian stuff. Does it sound like the original? It tries real hard, but the Tung-Sol snob in me would still go with NOS.
    They light up just fine. :)
    fortherecord likes this.
  12. -19db

    -19db Active Member

    Last I heard, the SED Winged C 6550's were no longer in production, although some online dealers still have stock. I purchased a couple of quads last year for less than half the price of NOS GE 6550s. Sonically, the SEDs are nearly as good as the GE's but don't seem to have the same durability.
    The V1 5751 in my CJ MV75 always flashes on startup no matter what brand of tube I have in that position.
  13. BayouTiger

    BayouTiger Forum Resident

    New Orleans
    Last I saw the Winged C 6550 were running $100 each. I've had the new Tung Sol's in my VS110 for a year or so. I like them a lot. I guess some might say they re not as warm as some others, but I love the detail and clarity. I have heard that the KT120's sound better in the VS110 but last time I tried them I thought they made the amp run too hot.

    I upgraded my Ref75 to the SE version which uses the KT150's but ARC has said they moved to the 150 not for more power but expect the life to be 50% better than the 120's in the circuit.
  14. fortherecord

    fortherecord Forum Resident

    Upstate, NY
    Aren't all the Russian tubes being made in the same factory now, whether they be branded Gold Lion or Tung-sol, or EH, etc. etc.? They all must be pretty much made with the same parts and materials, right?
  15. ThorensSme

    ThorensSme Forum Resident Thread Starter

    I for one would love to know more about the differences between new sensor output tubes of the same type...I wouldn't presume they use all the same design and materials, but if someone has knowledge of the subject please share.
  16. Adam Guy

    Adam Guy Active Member

    Roan Mountain, TN
    +1 more for the Gold Lion KT88. For the $$ they are hard to beat IMO
    BuddhaBob likes this.
  17. jea48

    jea48 Forum Resident

    Midwest, USA
    Testing for the, great, good, and weeding out not so good, that's the difference.
  18. Von Zipper

    Von Zipper New Member

    Psvane KT 88 T 11 matched quad set. Received these tubes 1 week ago, so getting the hang of them at this point. I had been using Harma 5881 which came with my Leben SC 600. Pretty good tube as I found out that they were actually 6N3Ce tubes and were being being marketed under the Watford Valves brand Harma. This turned out to be Jeff Days' favourite tube for the Leben CS 600, and I must confess, works and sounds extremely well in my system. I picked up some new Shuguang EL 34 Treasures as an alternative for their midrange but found a little lack of extension in the upper and lower frequencies. Although a very musical and involving tube, my system was put together as a a very strong midrange contender, so these tubes were a little to rich for my taste. I actually preferred the Harma 5881 because they seemed faster and coherent from top to bottom and slightly leaner on my Harbeth 30.1's.
    My research led me to two sets of KT 88's: The Northern Electric KT88 and the Psvane KT 88 T11. First off, both are not cheap and I'm dealing with a quad set. Living in Canada does not help due to a low dollar vs USD. The NE's were just under a grand for 4 and that was before tax! The Psvanes were half of that so an order was put in.
    Received the tubes from Grant Fidelity's partner in Hong Kong, but one was damaged in transit. Send it back to Grant Fidelity in Calgary with the tube readings so it would be matched properly. Had the replacement in 10 days time. Great response/service by the way, thanks Rachel. So...........
    This is one very fine tube. When initially installed, they sound very good right out of the box. One of my pet peeves is the 200/300 break in period before the tube sounds the way it was meant to be. To me, this is waste as your leaving your amp on continuously running your CD/Tuner/DAC to bring the tube up to speed. When you consider the life span of an output tube, this is somewhat a shame. The good stuff started kicking in at about 25 hours and they are now at 50 and sounding pretty damn good. So the bonus is you can still enjoy your system from the get go. This is one seriously good sounding tube which seems to compete with the best NOS tubes out there. First off, dynamics are much more noticeable. This starts with incredible grip on the bass and the midrange is clear, detailed, transparent with a full but not overripe and extending to heavens up top. The tube creates an Acoustic Envelope that extends beyond the speakers and allows for a pretty decent depth field. Images have tremendous air giving lots of space and overall a fairly large and panoramic sound. And this is in the first 50 hours! Should be interesting where this goes at around 100 hours plus. I feel these tubes also mate well with the quad 6CS7 NOS Matsushita's at the input stage of the Leben.
    In any event those are my initial impressions of the Psvane KT 88 T11. The synergy with what I have seems to be there, creating a very moving, emotional and extremely musical experience.
    Regards, Von Zipper
  19. Dentdog

    Dentdog Active Member

    The Russian 6550 to me is the best sounding of the 6550-KT88 reissues. VERY system dependent however. While they are a bit drier they have good punch and a clear presentation. I've tried everything reissued except the EATs and like these the best.
    That being said, the original Tung Sol 6550s I recently bought NOS have given me what I looked for in my system since I put it together. Finding black plates, the earliest, or smooth Grey Plates, the next itineration has been next to impossible. I bought the early 60s three hole grey plates and upon initial listening was a bit concerned. Impatient I am. After two weeks though, they began to round out to what I had hoped for.
    A bit more clear vocals, made piano much better, every instrument began to sound more like the truth. They are expensive and I hated parting with the cash. Might buy another quad for backup.
  20. Louis Kirsch

    Louis Kirsch Forum Resident

    Rolesville, NC
    I went from the original Electro Harmonix in a pair of Rogue Audio M-150s driving the M/T on my Von Schweikert VR-4 to the Gold Lion which I thought were a bit better on the vocals to my current Shuguang 50 years and not much improvement over the Gold Lion, but damn they're pretty
    SandAndGlass likes this.
  21. Falcoron

    Falcoron New Member

    All Russian KT88 tubes are identical to EHX tubes, this info is here and makes some good reading and good info of fakes and genuine old tubes. Don’t be fooled by the fancy boxes and gloss lettering just but the Electro Harmonix and you will have the same tubes for less money. I am going to trey PS vane as I think these have a better quality control and seem a lot more reliable
    Russian tubes have been hit and miss for years but getting better as the Chinese stuff improves
    All the info you need here

    KT88 and 6550 Directory
    SandAndGlass and E.Baba like this.
  22. jea48

    jea48 Forum Resident

    Midwest, USA

    Heater current on a 6550 is 1.6A
    Heater current on a KT150 can range from 1.7A to 2A.

    Make sure the 6.3V Filament winding in the power transformer is big enough to handle the added load current.
    Short out the 6.3V filament winding in the power transformer and the rest of the power transformer is gone. The primary winding will overload and blow the AC Line fuse.

  23. art

    art Forum Resident

    Gold Lion for Kt88
    BuddhaBob likes this.
  24. E.Baba

    E.Baba Forum Resident

    Using these ^^ now.
    Thinking of trying Shuguang 'T' or 'Z' (what's the difference? ) or Psvane TII (etc?).

    Interested if anyone has comments on the Gold Lion KT88 compared to the Shuguang or Psvane Kt88 ranges.

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