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Favorite Current 6550

Discussion in 'Amps and Cabs [BG]' started by Jammin'John, Dec 5, 2004.


  1. I just got a bass amp that takes 6550's.
    Do any of you have favorites ?

    JJ
     
  2. Arthur U. Poon

    Arthur U. Poon

    Jan 30, 2004
    SLC, Utah -USA-
    Endorsing Artist: Mike Lull Custom Basses
    When I owned all tube SLM/SVT's, I replaced the stock Sovteks with Svetlanas once the amp's output seemed to drop. It really didn't make a huge increase in output. I'm by no means a tubes or tube amp expert, but I've read here that many 'Brand Name' tubes are produced in different countries and their performance varies. A lot of the tube amp guys on this forum prefer NOS (new old stock) tubes over the current tubes. I understand the NOS tubes cost more, but they'll have a really long lifespan and increased output.

    Contact:LordValve@prodigy.net

    I can't remember his actual name, but his prices seemed fair and he was very knowledgeable.

    Best wishes, -Art
     
  3. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile
    I've been researching it.... I'm going for the Tung-sol reissues from new sensor (placing my order right after the holidays). But think the Electro Harmonix KT88 also look like a solid "current production" tube.

    www.tubedepot.com is where I'm ordering from.
     
  4. BassGreaser

    BassGreaser

    Aug 22, 2002
    Austin, TX
  5. $ 320 + ship ......... :eyebrow: .........That's a lot of money !
    The amp comes with real Svetlana 6550C's...........
    I can buy them for $100 a quad. :hyper:
    Yes,I know the arguements about NOS.
    I play tweed amps & have NOS tubes in 'em. :cool:
    I have also heard that GE's are great & last really long.
    I've seen them cheaper.
    I also heard that Tung Sol (the REAL AMERICAN ONES) are to die for. :D
    I think the new ones are china made :spit: are they any good ? (I hate givin' my money to china). I was just wondering what you guys were usin' in your giging rigs that is current production.
    My amp maker says to use 6550's.
    It's a tight fit in the amp & the bulge in the middle of KT88's MIGHT not work.
    Not only that............higher power tubes dont always sound better.
    I know...... :meh: ....... I like 6V6's better in my Deluxes than 6L6's.

    JJ
     
  6. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile
    They are made in the same factory as the Sovtek and EH stuff... in Russia.

    As far as gigging rig, I'm putting 8 in my 400 watt all tube head to replace the Crown CE1000 I currently gig with.... time will tell.
     
  7. BassGreaser

    BassGreaser

    Aug 22, 2002
    Austin, TX
    James let us know how you like them! I'm thinking about changing out the 6L6's in my bassman 135 with 6550's for more power, and head room:D
     
  8. Are you aware of the differences in the 6550's versus the 6L6? The 6550's require a whole lot more filament current and I don't know if your power transformer can handle the extra amps. (In fact, the whole power supply may sag so much that the 6550's may not give you any extra headroom at all, even if the heater current draw weren't an issue) Also of course the amp will require rebiasing and maybe some other resistor changes as well.

    In other words, this isn't a simple plug-in mod. I've heard of lots of people subbing 6550's for 7027's in the Ampeg V4's but I don't recall hearing anyone putting 6550's in a Bassman. I suspect the PT in the V4 is a lot beefier than in the Bassman.

    PsychoBassGuy would certainly be more knowledgeable than me with respect to this mod. Hopefully he'll see this and chime in.
     
  9. Rockbobmel

    Rockbobmel Supporting Member

    My V-4 has old RCA 7027As (retubed in 1986) in it, but if they ever STB, The 6550 would be way cool. The amp sounds AMAZING as is, but not enough power for an 8-10.
     
  10. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile

    +1 PBG is one of the most knowledgeable and straight shooting guys when it comes to tubes.

    I've heard of the swap... but it's usually 2x 6550 replacing 4x 6L6 and about the same output.
     
  11. Save your money and get the SAME EXACT tube for less than half the cost and call it a Sovtek KT88. They're BETTER tubes than real old US Tungsol 6550's, BTW.

    A Bassman 135 needs a new filament transformer, much better filtering, and a VERY good tech's attention for 6550's. It will significantly increase its output, unlike subbing 6550's in the Ampeg V4, but you're going to spend some serious cash to do it.
     
  12. BassGreaser

    BassGreaser

    Aug 22, 2002
    Austin, TX
    well of course it isn't a simple plug-in mod. I've talked to a local tube guy who designs his own tube amp, and he says the output tranny is more than big enough, but the amp will require some other mods to do the switch. Right now the bassman has 4 6L6's putting out around 100watts. With the 6550's I should be getting around 200watts.
     
  13. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile

    Hmmm... without seeing them together I wasn't sure. I know they are from the same shop and the glass looks identical. The Tung Sol boasts "Triple Getters" does the Sovtek have the same? I haven't found that in my searches.
     
  14. BassGreaser

    BassGreaser

    Aug 22, 2002
    Austin, TX
    James have you played through the peavey yet. I like the tweed look it has, and how the birdseye maple on your 6er is aging:D
     
  15. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile
    I snagged a set of generic chinese tubes from my tech for close to nothing... just to mess with it quiet here at home. I cannot wait till after the new year when it hits the shop and I can open it up with the boys. I just picked up a few JAN, EHX and JJ 12AX7 that should be arriving shortly...

    The birds eye is getting between an hour and 5 hours of play a day and yet to show a mark... it's "stabilized" by Larry @ galleryhardwoods.com and should out last the frets in my 5 string
    :bassist:
     
  16. "Triple Getters"- translation: three silver spots on the glass, the top is shiny silver with one spot on each side, and yes, the Sovtek KT88 has them.

    The Sovtek KT88 is nearly physically identical to the original REAL Tungsol, too, but it can take voltages that would melt the original and puts out more power. I expect New Sensor will discontinue selling them as KT88's pretty soon.
     
  17. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile
    thanks again Psyco.
     
  18. PBG...........you said "Save your money and get the SAME EXACT tube for less than half the cost and call it a Sovtek KT88. They're BETTER tubes than real old US Tungsol 6550's, BTW."

    I just got a used amp that has the SED 6550's & the maker says the amp is set up for them.
    My question is twofold :
    (1) Electrically...............can I use the Sovtek KT88 with
    just a rebias ?
    (2) Physically are they fatter or taller 'cause I don't have
    much room between tubes ?

    Thanks, JJ