KT90 vs KT88, which one?

Discussion in 'Tube Audio' started by PR Audio, Dec 4, 2011.

  1. PR Audio

    PR Audio Super Member

    Messages:
    3,381
    Location:
    Puerto Rico
    Does anyone own or have auditioned Meixing Mingda KT90 or EH KT90? How do you compare to a Gold Lion or Shuguang Treasure KT88? What is your preference and why? Any other favorite KT88 or KT90 that can be found today as new or NOS?
     

     

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  2. tubedude

    tubedude Sir-Wants-A-Lot

    Messages:
    97
    Location:
    Steamboat Springs, CO
    Dumping some serious coin, huh? What type (make&model) of amp are these going in? I've got a buddy that uses those uber expensive Shuguang Treasure KT88s and had nothing but good things to say about them.
     
  3. persil

    persil Well-Known Member

    Messages:
    624
    Location:
    London UK
    I have used the Mingda KT88s and They are Shuguang basic KT88s, the standard Chinese tubes. All KT90s supplied new are made by Electro harmonix in Russia. I find the KT90s good reliable valves sounding a little brighter than most 88s, I like them! The stock chinese 88s are fair valves for the price but I hear of reliability issues?

    As for KT88s, depends on your amp? I have a Mingda built amp that came with the EH 88s and they show up as a well balanced reliable valve at a very good price! Bang for bucks comes, for me, with the JJs, they come alive with my amp! With other 88s I have had I found the Genelex to sound very balanced, but unreliable and for that reason I no longer use them.

    If price is not a problem I have found the Treasures to be excellent, i have used a quad for 4 months, no problems so far and the nearest tonally to the "Jewels in the Crown", Original GEC (Genelex) NOS KT88s!

    I am lucky to have a large stash of the GECs, my working Quad are 30 years old, been in service for over 15 years now and are not showing any signs of wear at the moment. imho. no other KT** comes near to them! BUT you have to pay a lot of money! At the moment NOS balanced matched pairs are appearing in the UK and sell for £600.00. from trusted valve sellers. Worth the money? thats up to the buyer to decide!

    I have played with the new KT120s and if your amp can cope with the extra heater current draw and other parameters that are different then they do a great job for the bucks! Just remember they are NOT a direct replacement for the KT 88/90.
     
    Last edited: Dec 5, 2011
  4. babblefish

    babblefish Active Member

    Messages:
    351
    Location:
    San Francisco, CA
    So what are the spec differences between a current KT90 and the original Genelex KT88? I'm talking about the real KT88s, not the current copies/fakes.
     
  5. DanO55

    DanO55 Radar - BSFR

    Messages:
    2,432
    Location:
    Las Vegas-Sin City
    I wouldn't call the new issues "fakes". They are reissues. I use several different brands of KT88 in different tube amplifiers. The initial offers of the reissued Gold Lions did have reliablity issues. I don't find that to be case now. Not up to the original for sure, but for the price, I like em. Alot.
     
  6. babblefish

    babblefish Active Member

    Messages:
    351
    Location:
    San Francisco, CA
    Sorry, I didn't mean to imply that the current KT88s are inferior. My concern is that I've heard stories of non-original KT88s self destructing when used in amps with high (>475V) plate voltages like my HK Citation II.
     

     

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  7. chuckworkb

    chuckworkb AK Subscriber Subscriber

    Messages:
    3,225
    Location:
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    I have always wanted to try the Shuguang Treasure KT88, but didn't due to the price.

    I had issues with the new Genalex KT88's. I had one go bad and take out a resistor in my amp after only about 60 hours of use.

    I have Penta KT88's in my amp at the moment, and like them.
     
  8. Freo-1

    Freo-1 Well-Known Member

    Messages:
    797
    The Black Treasures are indeed a nice tube. I've not noticed any reliability issues with them to date. The Chinese tubes seem more robust than the Russian KT88's I've tried.

    The best sounding KT88 I've heard to date is a tossup between the Canada Fuller and the EAT KT88. The EAT's are WAY too pricey to even consider. The Canada Fuller sounds every bit as good as the EAT, and while not cheap, its way less costly than the EAT tubes.

    The Canada Fuller tubes are a step up in sound quality from the Black Treasures (more than I would have thought before hearing them). The sound upgrade from them is as pronounced as changing out the most significant preamp/driver tubes in the amp.
     
  9. boosted_sled

    boosted_sled Active Member

    Messages:
    158
    I've got a Cary SLI-80 that runs 570v B+ and ate a set of "Winged-C" Svetlana KT88's in 3 years. I've currently got EH EL34's in it which sound fine but I wouldn't mind trying another set of KT-88's. Do any of the current production KT88 or the KT90's have a good rep for long life at high B+?
     
  10. babblefish

    babblefish Active Member

    Messages:
    351
    Location:
    San Francisco, CA
    That was my question a few posts back. The original KT88s don't have a problem with it, but not sure if any of the current stuff is up to snuff.
     
  11. speakerfritz

    speakerfritz Well-Known Member

    Messages:
    511
    I have an few amps that can use KT-88's, 6550's, or KT-90's. Have tried the amp with sets of each. The tubes themselves lend to a different sound. I'm sure tube brands and era of production will also contribute to different sounds as well. Sound wise I like the KT-90 the best, and probally the 6550 next. KT-88's don't wow me and sound pretty much like EL-34's. When using KT-90's instead of KT-88's or 6550's, you need to understand what the bais range of your amp is. I find KT-90's draw the least bias current under the same circut conditions followed by 6550 and then KT-88's. Main issue is that your amp may not have a wide enough bias adjust range to tube the tubes in to the correct bias. My amp spec's for tube bias of 30 to 35 ma's. But can be adjusted down to 20ma's. So my amp can actually run 6l6GC's, el-34's, kt-90's, 6550's and kt-88's. I don't bother with hot tubes that have very high Ip numbers and would rather have tubes that have Ip numbers in the 28 to 31 range.
     

     

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