SVT 2 pro power tubes

Discussion in 'Amps and Cabs [BG]' started by LBronson, Dec 31, 2008.

  1. LBronson


    Dec 31, 2008
    I'm new, and so far the threads seem to confuse me more on this topic. It's time to change the power tubes on my Ampeg SVT II. The amp is 15 years old and seen a lot of use. If anyone out there has changed them I'd like to here what you put in and how it sounded. Don't be offended but if you didn't do this in your own amp please don't reply. I love the amp and its sound. The pre amp tubes are fine, changed them last spring. If you noticed any changes in sound, good or bad, I like to here what you used. Thanks, Larry
  2. ggmcgee

    ggmcgee Guest

    Dec 28, 2008
    You'll want new KT88/6550 tubes, and Tube Depot has a bunch of them with pretty decent descriptions of each type:

    I'm a Sovtek fan because 1.) I'm poor, 2.) they're very durable, and 3.) they seem to be louder, but that's a subjective thing. I'd go with these, but like I said, I'm a Sovtek fan.
  3. LBronson


    Dec 31, 2008
    Thanks. Love the 1300.00 price for 4 tubes. Wow. Looks like EH or Solvtecs for me.
  4. Hoss


    Jan 9, 2006
    Vienna, Austria
    Those EAT Tubes are priced ridiculous. Even if they can last three times longer, I am better with just buying three well matched sextetts of russian current production tubes... :D
    EAT rebranded NOS Tesla KT88 at first and then obviously started producing themself?

    As a recommendation and SVT user myself I can tell you that it is more critical WHERE you buy the tubes as the brand of them. Output tubes need to be tested, selected, burnt in and matched. They will be a little bit more expensive but it pays off! I personally like SED 6550 (strong low mids and strong bass, sound warm) and Sovtek KT88 (very strong mids, nice highs, tight bass, sound harder and colder).

    European dealers I can recommend are TubeAmpDoctor (good sets of SED6550) and Watfordvalves (their Harma 6550 are rebranded Sovtek KT88).
  5. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Any particular reason you're doing that or is it just because they're 15 years old? I wouldn't go throwing money at tubes that are working fine. I've got some tubes from the 60's and 70's that see regular use that still test as good as the day they were made. So before you go throwing out good tubes, I'd get them checked first.
  6. Warpeg


    Jun 20, 2005
    I tried both EH and Sovtek 6550's in my 2 Pro. I agree with a previous poster that the Sovteks are very durable and loud. They cut through a live mix like butter and have excellent overdrive potential. However, the EH's just have that thick, deep, punchy, traditional SVT tone. I did an A/B test between my old '72 SVT with original tubes and my current SVT-2 Pro with EH tubes. With the EH's I could get an identical tone to the '72!

    It's really a hard call to make between the two. If I had to pick one over the other, I'd had to go with the EH's.
  7. LBronson


    Dec 31, 2008
    Jimmy- My amp tech found they were starting to fail. Yea I have a 74 Hiwatt 100 with the original power tubes that still rock but the Ampeg saw daily use in a smoke filled bar for many years. Thanks for all the reply's. I'm looking at some tung sol's right now. I'll let you know how they work out.
  8. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Tubes don't "start to fail".

    if they fail once you don't wait for them to fail again...

    They start to *wear out* the first time you turn them on, but it's a long process.............

    Otherwise they "work" or they "fail". They can't do both......... or "partly not work". As long as they work, they are good.

    Maybe he means 'they are getting weak"...... which would have made sense. then they would be "good tubes with low gain".

    But tubes don't "start to fail".
  9. Surly


    Feb 2, 2007
    South Florida
    Put your amp on a bench, or let your ears be your "meter". If the amp is loud and has the tone you like, just leave it be. Otherwise if you really want to get new tubes, I've had no problems with I use the Svetlana 6550C's in an older SVT and they put out full power on the bench. Also the Tung-Sols have a good reputation. Buy a matched sextet in your budget, bias, and you'll be fine.