Shuguang 6L6s

Discussion in 'Amps and Cabs [BG]' started by mgmadian, Apr 25, 2004.

  1. mgmadian


    Feb 4, 2002
    Austin, TX
    Anyone tried these power tubes in their amp (esp. a Boogie Bass 400+)? I've heard a good things about them, and they supposedly can 'play well' w/the fixed Bass 400+ bias, plus they're relatively inexpensive ($115 for 12). Any insights appreciated.
  2. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Hi Greg, well, this is just my opinion (based on about ten years of experience), so take it with a grain of salt. But, I wouldn't let a Chinese tube get anywhere close to my amp. The darn things are notorious for their short life and lack of quality control, and the chances are "significant" that they could go belly up on you in the middle of a gig (and take some other expensive components with them when they go, like maybe a power transformer or an OT).

    For me, the number one thing with a tube bass amp is reliability. Sound is almost secondary to that, all the great sound in the world isn't going to help you if your amp isn't working! I'm using the JJ 6L6's in my tube amps, they're extremely reliable, and I've never had one go belly up on me (even in the face of considerable abuse). They're about 50 or 60 bucks for a matched pair, or a hundred for a matched quad. They sound great, nicely balanced tone without any boominess or icepickiness.

    My advice would be, with a nice powerful amp like that, don't try cut any corners by using cheap tubes. I'd even suggest going the other way, for example, you can still find quads of old RCA 6L6's that are "reasonably well matched", you can't go wrong with RCA's in terms of reliability and longevity. They might be a little more expensive (or a lot, depending on where you get 'em and if they're really "new" or not), but they'll pay for themselves in terms of the number of times you have to swap tubes, and the problems you might encounter when you do.

    Just my 2c...
  3. mgmadian


    Feb 4, 2002
    Austin, TX
    Hi nonsqtr,

    Thanks...I hear ya about the reputation of Chinese tubes in general. I wouldn't have considered them had they not been recommended to me by a fairly well-known 'tube guy', whose service + advice I've been happy with over the years as a customer. He even liked them over higher-cost (and better known) tubes for this particular application (specifically, in the Mesa Bass 400+).

    That said, I'm new to this all-tube setup. I love the sound, but I'm still going up the learning curve and am particularly trying to figure out the best strategy for the power tubes, since (a) they're a pretty big investment, and (b) you can't really try before you buy (seems that different ones will/may work better with bias adjustments, i.e. an amp tech visit), and (iii) the resale value drops a lot once they're even slightly used.

    And what happens if just a single tube goes bad, one year after putting in a new matched group of 12? Can you just plop in a new (same brand/model) one to replace the bad tube? Replace the bad tube and its 'partner' with a new, matched pair? Or should you replace all 12 and have the bias adjusted again? EDIT: Hmmm... I was initially asking these questions rhetorically, but come to think of it, I'd love to get the answers! :D

    Hence the search for an inexpensive power tube in particular. Definitely would NOT want to compromise tone or reliability, but if there's indeed a best-of-all-worlds tube out there, I'd love to hear about peoples' experiences with it!
  4. JJ's 6L6 are the way to go if you want new production tubes.
  5. Lord Valve's been pretty picky about Chinese tubes and with good reason; most have been absolutely terrible. Not all Chinese power tubes are crap, however. Their KT88's have been pretty good for years and now the rest of their production is catching up in quality. The new "Shugang" labelled tubes are made on old GE machines, they're the SAME tubes that Groove Tubes tries to pass off as their new "US made" line, and they're pretty good from most reports, although I have no personal experience with them; haven't needed to buy more tubes since I quit repairs.

    Be glad there's a resale value AT ALL. I have yet to ever see anyone looking for a used power transistor for sale.

    Ideally, the dealer you've bought them from will have measured their transconductance and matched them accordingly, so all you need to do is get a new tube that specs similarly with your dealer. Different dealers use different methods, so be sure to go to who you bought the tubes from initially. Even if there ends up being a small difference in biasing, it's not that big a deal, so long as you can get the amp to maximum output without anything burning up. Obviously, this falls in the realm of a tech.

    I'd say give the Chinese tubes try if you're set on them. They're as close to what used to be made here as you're likely to find, although JJ's are excellent, too. Until "Flying C" (formerly Svetlana) learns how to make tubes that aren't dangerously microphonic, I'd recommend you avoid them. Sovtek/EH/"new" Svetlana makes five or six different 6L6 variants and each one has its own particular quirks.