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New To Tube Heads

Discussion in 'Accessories / Connections' started by stealthy, Feb 27, 2009.

  1. stealthy

    stealthy Guest

    A few years back I purchased a Crate Blue Voodoo 60w tube head. Ive recently heard about tube replacing and would like to know more about it. Since I've had it, I have never changed the tubes, and who knows about the previous owner(s). How can I diagnose my tubes, and what (if needed) should they be replaced with? I know very little about this head!
     
  2. taxman

    taxman Active Member

    If it is working, you don't need to replace anything. Tubes should only be replaced with the same type tube. Although they are not nearly as long lived as transistors, they can last many years.
     
  3. NCdan

    NCdan Guest

    Tubes will die over time, but you should notice right away if a tube NEEDS to be replaced, because the sound will become very dull, there might be a lot of noise or humming, the volume might be really low, but something drastic will happen. As taxman stated, you generally need to replace tubes with the same type of tubes (replace 6L6's with 6L6's), but there are other tubes that will work, so you might be best off calling Eurotubes and seeing what they recommend, because they are very knowledgable and helpful and will even match tubes. Sure, they cost a bit more, but they're worth it.
     
  4. RemyRAD

    RemyRAD Well-Known Member

    One thing to understand about tubes is that unlike transistors, even when you use the identical part number made by another manufacturer, it will not necessarily sound like the original units. And back in the day, there were lots of different tube manufacturers. Today, that number has dwindled to just a few with inconsistent manufacturing techniques beyond the inconsistencies of the old-time manufacturers. And even back then, when trying to replace my Neumann U67 EF86 tubes, from TELEFUNKEN to Sylvania, GE, Raytheon, RCA, Tungsol, the results were dreadful! I went back to using the noisy old TELEFUNKEN tubes because they sounded way better than any of those others. I just have to let them warm up a lot longer, on the order of 3 or more hours. Needless to say, those rarely leave the confines of my studio except for very special jobs, like 1940s classic jazz at the Corcoran art gallery in Washington DC. But then for those, I'll also take out the RCA 77 DX's. No, I don't plug goes into my ALTEC tube preamps. I actually prefer my transistorized preamps.

    Toobs is tubes. NOT.
    Ms. Remy Ann David
     
  5. stealthy

    stealthy Guest

    Good info...thank you.


    The problem is, through the 3-4 years Ive had this amp, I've only used it a few times so I dont know how this amp should actually sound. Its been moved from Ohio to Florida, and back to Ohio. Its also sat in storage for the last 8 months.

    Is anyone familiar with this particular amp? Or have any suggestions on which particular tubes would produce a better sound? It seems this amp lacks low end, and has too much treble. Looking around on musiciansfriend for new tubes, Im not sure what to be looking for. From what I've read, this amp's pre-amp section contains three 12AX7 and the power section contains one 12AX7 and two 6L6. What does it mean that the rectifier is solidstate? What are good tubes to look at when the time comes for replacement?

    And whats the proper way to warm up/use this amp? Concerning the on/off and standby switches?

    Sorry if this sounds rudimentary, but I've had zero experience with tube amps.
     
  6. NCdan

    NCdan Guest

    That is impossible, because amps almost always need a high pass even with the lows turned down all the way. A high pass is basically turning the subs and lows down. Think about it: there's an instrument called the bass guitar that handles the bass frequencies really well. :wink: I find it extremely hard to believe that an amp with 6L6 power tubes has too much treble.

    This really depends on what tone you want. There are two commonly used types of power amp tubes: 6L6's and EL34's, with other tubes generally falling somewhere in between those two sound-wise. Most amps can't use both 6L6's and EL34's, but some amps can be switched to accomodate either one. 6L6's have a deeper tone that is more straightforward and less raw. There are variations on 6L6 tubes and even some other types of tubes that can work with your amp, but you'd really be best off calling Eurotubes and talking to someone and describing what kind of tone you're after.

    You turn the power switch on first, wait a few minutes, then turn on the standby switch. When you want to turn the amp off you turn the standby switch off, wait 5-10 minutes, and then turn the power off.

    And just so you know, tube amps generally don't sound good unless the master (main) volume is turned really high, like from 7-10. I don't know if the Blue Voodoo has a master volume or not. And lastly, tube amps always need to be connected to a speaker when turned on, or very bad things can happen. Well I hope that gives you an idea of how to use tube amps. And call Eurotubes if you want to change tubes: they are extremely professional and helpful, and will even match tubes and come up with personalized preamp and power amp tube combinations to nail the sound you describe to them. God bless.
     
  7. stealthy

    stealthy Guest

    Ok, understood :)


    Ive read that Groove Tubes are relabeled Sovteks and chinese brands. True?

    After looking around and reading many many reviews, I'm considering a matched pair of Ruby Tubes 6L6GC STR's for the power section, 1 Tungsol 12AX7 for the power section, and 3 Tungsol 12AX7's for the pre amp section. I think the Tungsol 12AX7's may suit me better than the Rubys.

    When breakup is talked about, whats the difference, what is better for what goal?


    Because of the age and conditions this amp has gone through, I feel as if I should replace the tubes. Is this an easy task for someone who has never done it before?
     
  8. Greener

    Greener Guest

    NCdan, cranking the main side of the tube amp only gets the power tubes working. A vast amount of good tone can be had from driving the pre side of the amp balls to the wall and having the power side just working nicely on a low setting, so SPL in the room isn't muddying up the place...

    Also, you say...
    "That is impossible, because amps almost always need a high pass"
    And...
    "I find it extremely hard to believe that an amp with 6L6 power tubes has too much treble. "

    Have you ever heard the amp that is being discussed here, either this one specifically or any others like it in general? You're generalising a lot.
    Not everyone wants to sound like an Angry Gerbil...
     
  9. stealthy

    stealthy Guest

    And just for the record, I play mostly hard rock/hardcore stuff.
     
  10. Davedog

    Davedog Distinguished Member

    Seriously. Call Eurotubes and talk with them. they are complete experts in tube technology and have probably dealt with your amp model.

    I'm really not kidding.
     
  11. cfaalm

    cfaalm Active Member

    To start off I suggest you read up here and here. They are commercial sites but they also share a bit of info on the tubes. There are lots of other companies offering tubes e.g. this one, which is in Germany and that one which is in the UK offering very special stuff. I forgot to check your location.

    Any tube you stick in your amp head will change the sound for better or for worse. You would have to know the characteristics of a tube to make a decision. I suggest to contact the manufacturer and see what they recommend as replacements before you buy anything. A couple of sockets might require a so called "selected" tube, which means low microphonics. Most good tubes will cost just a tad above EUR 10,00. It doesn't have to cost more than 20 though.

    With powertubes the road is much narrower since you will most times have to make a 1:1 replacement and if they're not the same "bias", adjustments will have to be made by a qualified amp doctor. Some amp heads can work with several types of powertubes, Koch amps can. But they will need adjustments in order to work as advertised.

    I had stock 12AX7s in my ENGL 570 when one of them turned bad (in my case I got a loud hum in the lead channel). Engl told me I can mix and match because the amp would work anyhow. I replaced two of the stock tubes with a 12AX7 from Electro Harmonix and I am very pleased with them. I also got a GE JAN 5751. This is a low gain tube. . I can never have a decent drive with this tube though my clean will never sound better. I will probably try this in an el cheapo Art Mic preamp one day and see what it does. I also have a JJ 12AX7A that was too noisy and a Sovtek 12AX7WB (lower gain). The Sovtek just didn't sound that special to me, but it might have been OK in your amp.
     
  12. stealthy

    stealthy Guest

    See, I did notice that the Tungsol 12ax7's are high gain and the Ruby's are low gain. Should I get a Ruby for my clean channel and the Tungsol for the overdrive? What is the 3rd pre amp tube for? And why is there 3 power tubes and consisting of two 6l6's and one 12ax7??
     
  13. NCdan

    NCdan Guest

    Yeah, but... You know. I agree with you, but I think cranking the master and keeping the preamp volume(s) low is better than the other way around. Not that cranking the preamps and leaving the master low gets you bad tone, but I'm talking ideally here.

    Yes, I'm somewhat familiar with the Crate Blue Voodoo. I think the problem here might be terminology. Maybe the amp has a natural edge to it, but I doubt that it has too much treble. Do you record electric guitars with the subs not attenuated? I mean at some point you are going to attenuate or high pass, right?
     
  14. Greener

    Greener Guest

    Never used a filter or an EQ for any tracks I've recorded.
    If it's too bassy or muddy I mess with the mic/amp position or the amp settings.
     
  15. Davedog

    Davedog Distinguished Member

    You're not listening.

    First. A 12ax7 is NOT a power tube. It is either a preamp tube, a phase inverter or a driver for the reverb tank.

    The6L6's are the power tubes.

    Brandwise, some manufacturers have different values for their models of tubes than others.

    This why you need to consult with someone who really does know exactly what tubes, which brands and why they do what they do in order to get a clear idea .

    You need to call Eurotubes. They are on the net. They have more than likely dealt with your particular amp in the past and have documented its reactions to differing tube types .

    Or you can keep posting your assumptions. And learn nothing in the process.
     
  16. zetasong

    zetasong Guest

    ...own a 96 60w crate bv combo w/ a single 12" speaker...your a combo or separate head cabinet???.....

    .....best....a...
     
  17. stealthy

    stealthy Guest

    head, not a combo
     

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