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400+ Question

Discussion in 'Amps and Cabs [BG]' started by jugdish, Apr 9, 2001.


  1. jugdish

    jugdish

    May 25, 2000
    Orange County
    Hi there I've got a question about clipping with a tube amp. I run my G&l through the active preamp of my mesa 400+. But I have to run the master at around 7 and the gain at around 8 for shows. I want to run the G&l through the passive input but don't know how the amp will handle it. How does a 400+ let you know if its going to clip??
     
  2. Oh my god master at about 8???? gain at 7? hmm how do you have the rest of your settings mid, bass and so on? do you use the EQ at all? If I run my amp at 2 with gain at 7 i almost blow my bandmates off their feet. Do you have a very inefficient cab? The "passive" input works fine too, it is just a little bit higher gain and a little bit different tone. The 400+ is all tube so you will just get some of that nice tube distortion when it clips nothing to worry about. I would worry about why the output is so low instead. Maybe your tubes are going bad, and causing this low output. I dont know. But my 400+ with master 2 with an SWR BigFoot cab will almost knock me over. I play an MM Sterling mostly through input 1 (for active as you would say).
     
  3. jugdish

    jugdish

    May 25, 2000
    Orange County
    I have a mesa 2x15 and the eq set sort of like a smiley face, high bass & high treble. Problem is that I play alot of places with no PA's and my guitarist uses 2 100 watt set-ups. I've had the amp for about 1.5 years but have always had the master and gain settings like that. Still have the stock tubes in it with no crackling or popping noises, no microphonics. I have a G&L L-2000 and Musicman Stingray. I've just always heard people saying the same thing as you Mesa Man that they can run the master at 2or3. Does anyone think replacing the tubes would help? I've heard good things about Svetlana.
     
  4. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    What's the rating of the cab? Could be that you 'overdrive' the cab, not the amp...
     
  5. jugdish

    jugdish

    May 25, 2000
    Orange County
    Cab is 2x15" 800 watts 4ohm or 8ohm and I'm just running the amp in 4ohm.
     
  6. jugdish

    jugdish

    May 25, 2000
    Orange County
    Can any other 400+ owners tell me the tube choices they used and how to go about changing the tubes. The amp is supposedly biased but if I get a set of tubes matched to Mesa specs can i just drop them in no sweat??
     
  7. killer B

    killer B

    Apr 18, 2000
    Phoenix, AZ USA
    You can drop in a replacement set of MESA tubes with out having to adjust the bias unless the amp is very old then you may want to have it looked as the bias can "wander" after years and years of use. You can also order a set from www.lordvalve.com that can matched to MESA's spec's for the BASS 400+ and then just dropped right in.
     
  8. jugdish

    jugdish

    May 25, 2000
    Orange County
    Thanks Killer not really interested in trying mesa tubes due to the question on where they are coming from. Don't want to pay 250$ for tubes that might be chinese. I talked to the guys at the tubestore and I'm thinking of
    Svetlana 6l6GC's for the power and
    Sovtek 12AX7LPS for the preamp tubes
    Anybody have recommendations on these tubes.
     
  9. Hmm strange thing, you run a mesa 2x15 with master at 8.. utterly strange! Are you using an instrument cable for the cab? This is NO good, make sure to get a proper cable, made for speakers. Not have to be flash just a speaker cable. Does your amp run hot? Have you checked the battery in your bass´ preamp? How old is your 400+? I cant see the use of changing tubes unless they fail (or you want to change the sound) and when they do you will probaly notice. Todays tubes work fine until they blow, unlike the tubes from "back in the day" when tubes gradually degraded... and then blew.

    Is your amp dusty inside (just around the tubes)? It is an easy thing to clean up the inside of a 400+, just be sure not to have it plugged in when you do it. To be extra safe you should drain the caps and stuff, which is done like this: warm up your amp by playing it as usual for a couple of minutes, then just pull the plug litterarly (sp?) but continue playing until it has faded out. This will drain all current from the inside of the amp.. oh well you get the picture. :)

    Most important of all your amp shouldnt be at master 8 with a mesa 2x15 cab.. hmm do you have the cab plugged into the right jack for the speaker on the back of 400+ (stupid question but still..).

    Try my settings for my sterling (works fine with stingray too i guess) and my 400+:
    input 1 gain 7
    mid: 5
    Bass: 6 (Pull shifted, you know knob pulled out)
    high: about 6 (also pull shifted)
    my eq is like an m in a way, but nothing is below 0db, the middle of the m is the center freq, i think it is 1000Hz?

    this and a light bass boost on my sterling will rock the house at master volume 2.

    Remember, the cutting sound of a bass is never achieved with a smiley eq. Cutting through is all about mids.

    Let me know how this works out.

    good Luck!
     
  10. jugdish

    jugdish

    May 25, 2000
    Orange County
    Thanks MesaMan my settings when I got the amp about 1.5 years ago were exactly the same. I think the power tubes have started to give up. I ordered some new tubes and I'll let you know if that fixes it. I played a last minute show saturday and everyone asked what was wrong with my equiptment. Bass just sounded non-existent compared to the rest of the band. The only good thing was that people still loved it and called out for and encore.
     
  11. Rickenbackerman

    Rickenbackerman

    Apr 17, 2001
    Laurel MD
    Hey guys, I'm new here. This place is pretty cool!

    I'm using a Mesa 400+ with two Eden 410XLT's...
    '66 Fender Jazz or 79 4001 into channel 2 - Gain between 4 and 6, all eq knobs on 5, master between 4 and 5.

    Mesa Man - master on 2??? Hmmm - I'm wondering if maybe mine needs some new tubes? Or maybe you're not at the volume I'm at...
    I have to keep up with a loud drummer and two marshall half-stacks, and we are definitely a high-volume rock band. The fact that you use the pull-shifts might boost your low end volume more as well... I like it real midrangey...

    I also have a '73 SVT which is in the shop right now, I may end up using that once I get it back...
    Rob
     
  12. hmm the efficiency of the cab is an important factor for the overall loudness of the amp/cab, but I cant see why the Mesa 2x15 would be that inefficient. I use an SWR BigFoot 2x12 with tweeter,. rather efficient cab and we have a LOUD drummer as well. I play an active bass but didnt you play a Stingray Jugdish?

    Welcome to the board Rickenbackerman, hope you like it here, I do, it is the best board on the web I think everyone is so very helpful.. like a family :)

    You could read my settings before Rickenbackerman, you know if you pull the high knob you will get some boost at about 1k I think.. i like it kind of midrangey too but its easy to play it that way when playing a Sterling :D

    Jugdish, this might be a stupid question but is your eq engaged? How are your other knobs set? The 400+ uses passive filters for the knobs so if you put all your knobs at "0" you will not hear anything at all. Try my settings, and please let me know if it still sounds less. you dont have to like it, just let me know. My M shape is kind of flat it is all set between 0 and almost the top for some frequencies.

    Let me know how this works out, maybe you should let a tech have a look at it, dont fall for the "well you know this amp needs biasing.." and then they will probably find that the amp has no bias adjustment installed and will charge you for that installation, if they do this go to another tech who knows Mesa's gear better. you could read about bias and Mesa at their homepage: www.mesaboogie.com

    Good Luck!
     
  13. jugdish

    jugdish

    May 25, 2000
    Orange County
    Mesa Man, thanks I'll try the settings tonight and see what the difference is. I have a lot of bass boost on it because I play with a pick and too much high and the sound gets a little twangy. Have you replaced the tubes in yours? My 400+ is in great condition( no dust or anythingaround the tubes and is kept in a shock case)
    Are there any hints for swapping the tubes? I got a replacement from thetubestore and they have been current selected for the 400+ but I've never installed tubes myself. Don't want to break them.
     
  14. Rickenbackerman

    Rickenbackerman

    Apr 17, 2001
    Laurel MD
    Jugdish - here's a thought about the fact that you might need new tubes - the boogie is designed so that it will still work if some of the tubes are blown, so maybe you have a few fried tubes.
    The easiest way to check if they're at least working (how well is another story) is to look in the back of the amp while it's turned on and see if they are glowing! Worth a shot...
    Like Mesa Man said, there is 'no way' you have to turn up to 8 with this amp...
    Rob
     
  15. jugdish

    jugdish

    May 25, 2000
    Orange County
    Well Rik it has not been a sudden thing. When I first got it for shows I might have the gain at 7 and the master at 4 but over the last year the volume has just needed to be turned up more and more. That just sounds to me that the tubes are getting old, which is what supposedly the first sign of power tube failure. That they stop producing the same amount of power. It was my understanding that powertubes shouldn't be run till they blow up before changing them because you can damage the rest of the amp. You should run the tubes till a noticible problem and change them. Am I wrong here??
     
  16. Rickenbackerman

    Rickenbackerman

    Apr 17, 2001
    Laurel MD
    Nope I think you're right on.... sounds like you need new tubes... You might want to look at them anyway while it's powered up - I'd bet some aren't glowing... BTW when I said tubes might be "blown", I meant either they are really blown or just aren't working to capacity...

    BTW they are easy to change - just grab the top of the bulb with three fingers, and pull and wiggle at the same time. You won't break one. I think there might be clips that hold the tubes in on the Mesa - I haven't had to change mine yet.
     
  17. jugdish

    jugdish

    May 25, 2000
    Orange County
    Thanks Rik, The amp is one of the best I've played just having to retube it and figure all this out is a bummer, and then to get a call on friday to play a last minute saturday show. The amp hung in there but I'm glad that the tubestore is delivering the tubes tommorrow. I'll let you guys know how it works out.
     
  18. timv

    timv Supporting Member

    Jun 7, 2000
    Chandler, AZ
    Usually when a tube blows it shorts out causing the fuse to blow on the head. You wouldn't be able to get the head to stay on until you took the blown tube out. I've blown a few in my bass 400+. IT isn't nice to see a bright blue light come from behind your head when you're playing. Good luck.
     
  19. I have never retubed mine, and i bought it used about 1,5 yrs ago. I noticed some of the tubes were changed since they were not as dusty. As Rickenbackerman said they are easy to change, but dont foget to pull the cord, before you change them, you know we do want to know the outcome of this tubechange! :) ;)

    Another thing that came to mind was: does the sound feel dull, not as fast responsing, biting, bright, bouncy or whatever you would say? This is according to those who works with tube amps a good sign that your tubes might be on their way so to speak :) Your preamp tubes work well i suppose?

    Changing the tubes will hopefully fix this, dont forget to turn your amp down before trying it with the new tubes. It might also be a good idea to start out with more neutral setting at the EQ and so on. By the way, did you buy your amp new from a store? if so then you should have a half off coupon for new tubes.

    Ok get back here as soon as you have changed the tubes! Promise! :)
     
  20. jugdish

    jugdish

    May 25, 2000
    Orange County
    To everyone who helped out thanks a bunch. I got the tubes for The Tubestore and swapped them with the factory tubes and everything was fixed. No more absence of power. Thanks to Mesa Man for the killer settings. Svetlana power tubes and sovtek preamp sounds killer.
    Thanks again guys