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

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

  1. ThorensSme

    ThorensSme Forum Resident Thread Starter

    Just looking for peoples opinions and preferences for current issue kt88 & 6550 power tubes.

    I have tried and liked SED winged c kt88, and New Gold Lion kt88. Of these two I think I prefer the SED.

    Also, are there any over arching tonal differences between 6550 types and kt88 types?
  2. DaveyF

    DaveyF Forum Resident

    La Jolla, Calif
    I really like the winged C SED 6550's. Not that easy to find these days. Replaced the GE NOS 6550's in my ARC D70Mk2. IF...a big IF, one could source the NOS GE 6550's in great condition, then i believe these are the only 6550's that may sound better than the SED's.
    ThorensSme likes this.
  3. nm_west

    nm_west Forum Resident

    Abq. NM. USA
    I liked the SED kt88's as well as old stock GEC's in my citations.
    The best bang for the buck for me [cheap bastard] is the Sovtek kt88's.

    I too prefer the SED's over the GL's. Never going to by Ruby kt88's again.
    ThorensSme likes this.
  4. ThorensSme

    ThorensSme Forum Resident Thread Starter

    Can 6550 tubes be put in place of KT88 tubes? My Line Magnetic 216 comes with KT88's, wondering what to expect form 6550 sound, and whether they are truly electrically swappable.
    rmbaker likes this.
  5. nm_west

    nm_west Forum Resident

    Abq. NM. USA
    It will depend on the amplifier circuitry. My mcIntosh and citations can do both.
    My best sound comes from using both types in two citation amplifiers with two sets of speakers.

    SED 6550's into Wharfedale w70's for that colored,rich sounding midrange.
    SED kt88's into norman model 10's for deep bass and extended highs.

    I didn't know SED made tubes anymore.

    Hendertuckie likes this.
  6. ThorensSme

    ThorensSme Forum Resident Thread Starter

    I don't think they do, these may be NOS, or maybe their website hasn't been updated.
  7. KT88

    KT88 Forum Resident

    They are essentially the same. Different tubes, but they can work in any application where the other was called for. The nuts and bolts of this whole thread has been covered here before, probably a few times. KT120's are even better. My hierarchy is basically thus:
    6550 / KT90

  8. And don't forget the KT150, a very high power 6550/KT88-type tube. It won't work in all amplifiers, but IIRC, if your amp can handle a KT130, it can most probably handle a KT150.
  9. Louis Kirsch

    Louis Kirsch Forum Resident

    Rolesville, NC
    I replaced 4 year old Gold Lion KT-88s with ShunGuang 50 years of treasures in my Rogue M-150 mono-blocks and I love the sound. Warm just the way I like it with the right amount of detail. And they look sexy as hell ;)
    Kyhl, rocky dennis and ThorensSme like this.
  10. Scott in DC

    Scott in DC Forum Resident

    Washington, DC
    ThorensSme likes this.
  11. krisjay

    krisjay Psychedelic Wanderer

    What are some thoughts on Electro Harmonix KT88's.
    Dmann201 likes this.
  12. SandAndGlass

    SandAndGlass Twilight Forum Resident

    I use Electro Harmonic KT88's in my Rogue M-150 monoblocks. They are what Rogue ships as standard issue in their amps.

    I have two other tube amps, a Rogue Chronos Magnum and a Decware Mini Torii that puts out 3.9 watts per channel.

    I have some wear on the EH tubes so I am going to order another set of one type or another. I would likely buy the treasure's just to see how they sound.

    One thing that I will say is, while many people do not consider EH to be good tubes, I would tend to disagree. They have been solid since I put them in two years ago. I like their sound. There is not one area that they are lacking in my system, which has a tube preamp and Altec Lansing A7 speakers.

    For the money, I don't think that they can be beat. I leave my amp on overnight quite often and I like the lack of guilt in running the amp so much, but with the lower cost of these tubes, I could go through a pair every year or so and not bat an eye.

    If I paid for much more expensive tubes (I use two quads in the M-120's), I would cut back on the listening a lot.
  13. dividebytube

    dividebytube Forum Resident

    Grand Rapids, MI
    Kyhl and ThorensSme like this.
  14. rocky dennis

    rocky dennis Forum Resident

    I also replaced GL KT88s with Shuguang black treasures in my McIntosh 275V and prefer the Shuggies. The Gold Lions are nice and reliable, but a little too "polite" for my tastes.
    ThorensSme likes this.
  15. Rolltide

    Rolltide Forum Resident

    Vallejo, CA
    I think I'm going to buy Shuguang tubes next solely so I can refer to them as my Shuggies.
    russk, BuddhaBob, samurai and 2 others like this.
  16. Tullman

    Tullman I prefer analog

    Boston MA
    I have KT120's and they are the best I have heard in my CAT amps.
    SandAndGlass and KT88 like this.
  17. That was supposed to be "KT120," not "KT130," which does not exist to my knowledge.
  18. ejman

    ejman Well-Known Member

    I was very happy with the Tungsol 6550 @ my Jolida 502 power amp. That is until I decided to try the Tungsol KT 150's. Wow. I was amazed at the increase in clarity and bass. I had to turn my sub down a couple of notches. I've read that there is no additional power if the circuit is not specifically designed for KT 150's but I'm not sure I believe it. There is just more umph there.
    ThorensSme likes this.
  19. When I had a Jolida 502 (the very first model, called the SJ-502A), I used "real" Svetlana 6550C's. This was before New Sensor bought the rights to the Svetlana name, and the Svetlana 6550C's were produced in the S.E.D. plant--in other words, they were the same tubes that were later called "Winged C." In any event, they sounded wonderful. I used Mullard 12ax7a and 12au7 tubes. The 12au7's flashed brightly upon power up, while the 12ax7a's were the military variant (CV4004, I think). Anyway, great sounding amp!
  20. ejman

    ejman Well-Known Member

    I really should try some of those old Mullards. Every comment I see praises them no end. Pricey though. I wonder how good the reissues are?
  21. IanL

    IanL Forum Resident

    Oneonta, NY USA
    The nice thing about those preamp tubes is they last a LONG time. You don't necessarily have to buy NOS. You could buy some used but good-testing Mullards (or Teles, Amperex, or whatever) and save some cash. They will probably last as long or longer than new current production tubes from Russia and China too.
    Billy Budapest likes this.
  22. Burt

    Burt Forum Resident

    Kirkwood, MO
    You'd do very well to measure the heater current on these before using them on any unit not originally designed with them in mind.
    jea48 likes this.
  23. Dmann201

    Dmann201 Forum Resident

    I've used the Gold Lion and Electro Harmonix in my amps and I'd recommend both. The Gold Lions seem to have more midrange bloom and the EH has a touch more sizzle on the top end. Both have good bass response and great soundstaging with a slight advantage to the Gold Lions regarding soundstage.
    SandAndGlass and art like this.
  24. All of my current small signal tubes (Telefunken 12ax7, 12au7, and RCA 5692) were bought "used--test good" and have been working and sounding ship shape for the last 13 years.
    IanL likes this.
  25. I miswrote up there--my Jolida used 12ax7a's and 12at7's (not 12au7's). The 12ax7a's were the ones that flashed upon power up. Pretty cool looking!

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