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Boogie 400+ underpower/distortion

Discussion in 'Amps and Cabs [BG]' started by mactac, Jan 25, 2006.


  1. mactac

    mactac Supporting Member

    Nov 28, 2005
    Victoria, BC, Canada
    ok, so I started a thread a while bak about an amp i was renting, a 400+ that seems to start distorting badly at a medium volume
    http://www.talkbass.com/forum/showthread.php?t=222740

    The concensus was that the amp was bad, most likely a tube problem.

    I just bought a 400+ from a TBer, and guess what - SAME PROBLEM.

    So, I have the vol1 (the preamp) on maybe 7 so it's not distorting, and if I turn up the master past 3 or so, it's breaking up like crazy. It's not SUPER loud either.

    I couldn't get enough clean volume for my show last night at a medium (100 people) bar. (i'll post some gig pix shortly!)

    I played through an eden 410xlt (700w)
    I also played my other amp that distorted through my ampeg 410hlf... so I know the cabinet isn't bad (unless for some crazy reason they are both bad, which i doubt very much)

    If I get a chance, I'll post some audio from he show, but it's distorted like crazy, trust me.

    Any ideas here? I'm stumped. BOTH amps are no good?

    Could it be that the cabs i'm using simply can't handle the volume & it's the cabs that are crapping out? any easy way to tell?

    Or could it be that I expect too much from a 400+ clean-volume-wise?

    help.... !
     
  2. 1up_SVT

    1up_SVT

    Jan 15, 2006
    try turning the master up more and the volume up a bit less? if i remember right the volume controls are pre gain and the master control is post gain essentially, so that might work

    I would also recommend taking it to a tech to have a look at it, might be a bad power tube or two, or something similar, remember, postal comanies dont have the lightest touch!

    300 watt all tube should be really loud, so something must be wrong

    Have you tried another cab with that amp, also, have you tried a different instrument cable, and a different speaker cable, do you have the cab plugged into the right output?

    Also, if you have an active bass it might need a new battery (or two)
     
  3. mactac

    mactac Supporting Member

    Nov 28, 2005
    Victoria, BC, Canada
    >try turning the master up more and the volume up a bit less? >if i remember right the volume controls are pre gain and the >master control is post gain essentially, so that might work

    The preamp is not distorting....it's the power amp

    >I would also recommend taking it to a tech to have a look at >it, might be a bad power tube or two, or something similar, r>emember, postal comanies dont have the lightest touch!

    remember, this is the 2nd one with exactly the same problem...

    >Have you tried another cab with that amp, also, have you

    umm... yes - that's what i said in my post :)

    >tried a different instrument cable, and a different speaker
    >cable, do you have the cab plugged into the right output?

    yes, yes & yes

    >Also, if you have an active bass it might need a new battery >(or two)

    no, it's not the bass.
     
  4. cheezewiz

    cheezewiz

    Mar 27, 2002
    Ohio

    Use a Y cable and plug into both channels. If you are using only one channel, use #2. It's higher gain than #1. Turn down the preamp gain to 5 or 6 on each channel. Remember, it has a Fender tone stack. 2 bass, 10 mids, 2 treble, is flat. With your master on 5 or 6, it should be loud enough for any gigs. If its breaking up, its your speaker cabs. BTW, how do you know it is the power amp and not the preamp breaking up?
     
  5. timv

    timv Supporting Member

    Jun 7, 2000
    Chandler, AZ
    Are the effects loop blend control set to zero in the back of the amp? My 400+ has old tubes and still is extremely loud with pre volume at 2 1/2 and the master at 2 or 3. That amp is extremely loud and I doubt you have 2 bad ones. Maybe post your tone settings and EQ. Check the control in back. Did you download a copy of the manual and go through that, it might help.....
    http://www.mesaboogie.com/manuals/Bass 400 Plus.pdf
     
  6. mactac

    mactac Supporting Member

    Nov 28, 2005
    Victoria, BC, Canada
    >Use a Y cable and plug into both channels.

    I did.

    >If you are using only one channel, use #2. It's higher gain >than #1. Turn down the preamp gain to 5 or 6 on each >channel.

    it's not the preamp ! :)

    >Remember, it has a Fender tone stack. 2 bass, 10 mids, 2 t]>reble, is flat.

    yep, i know

    > With your master on 5 or 6, it should be loud >enough for >any gigs.

    it wont got to 5 or 6. i said i had it at 4, but in fact i just checked, and i had it at about 3.5 when it started falling apart

    > If its breaking up, its your speaker cabs.

    ok, this is what i was thinking too. I'm fairly certain they are not broken. I am wondering if they cannot handle the volume?? the eden is 700w.... should this not handle it?

    >BTW, how do you know it is the power amp and not the >preamp breaking up?[/QUOTE]

    because turning the master up makes it distort. with tthe master at 1, it's clean. the more i turn up the master, the worse it gets.

    see, and vol 2 or 3, it is fairly loud just not loud enough for a gig.
     
  7. I also replied to your posts in the other thread. I have the same amp/cab (Eden D410XLT) that I can drive to obnoxiously loud volumes very cleanly.

    That's with the master at ~4 and the pre about the same.

    Do you notice the distortion immediately or after playing awhile? I've found that the 400+ gets a nice (to me) power amp grit to it after being pushed hard for a period of time.
     
  8. mactac

    mactac Supporting Member

    Nov 28, 2005
    Victoria, BC, Canada
    the distortion happens pretty much right away. Glad I found someone with the same cab & amp! :)

    i's not so much grit, but more full on distortion that i'm hearing here. up to 3.5 or so, it does seem loud... ie at 3 it's way louder than any other amp at 3...

    what are your tone controls set at ?
     
  9. cheezewiz

    cheezewiz

    Mar 27, 2002
    Ohio
    Despite your assertions that its the poweramp which is distorting, which I doubt...but that's just me, have you TRIED running the channels a bit lower?
     
  10. D.A.R.K.

    D.A.R.K. Supporting Member

    Aug 20, 2003
    Virginia
    have you tried another bass- same results?
    what bass are you using?
     
  11. Mid 7, Bass and treb 5-6, neither pulled. I like a somewhat mid scooped tone. I use both pre inputs, pre 1 at 4 pre 2 at 2 (pre 2 has higher gain, that seems to balance them out). Volume at 4 and she's loud and clean.

    That Eden cab will fart out if you drive it hard with too much bass below it's cutoff freq. I've had that happen with other amps (Eden) which have enormous amounts of EQ gain. I don't think I've every had it happen with the 400+ though.

    I've ran this amp with 2 cabs for large venues where I wanted a higher stage volume and moved the pre volumes up to 5 and 3 and the master to 5. Very loud and after a few minutes the power section had a pleasing bit-o-grit to her that I like a lot.

    Keep in mind, beyond 5 on the master doesn't seem to add appreciable volume to me. Try the master at 4, use the pre volume(s) to get suffcient gain to the power amp section. As you can see above, I don't need that much really with active basses. My power tubes aren't that fresh but I love the way they sound so I'm not changing them until I have to.

    If you have another amp with pre out or another preamp around you could try experimenting a little by running the pre into the effects return. Be sure to turn the loop blend control to 10. Slave amp should always be 0. You could then hear if you're experiencing clipping of the power amp section only as you'll have taken the 400s pre out of the equation. Sometimes I'll run an SVP-CL into the power section for grins.
     
  12. Caca de Kick

    Caca de Kick Supporting Member

    Nov 18, 2002
    Seattle / Tacoma
    You are setting your volume knobs backwards. Set the master high like around 7 or 8, and set your input volume low like 3.

    Also the Mesa works best if you plug your actives in input 1 and passives in input 2.
    I've been playing mine for over 15yrs now, it takes a little while do dial them in, then they're sweet!
     
  13. I've never had to turn my master up that much to have it at a decent volume. Kind of stuck to the manual recommendations . . .

    "Full undistorted power is developed at settings around 5. There is rarely any reason to run the Master above 6 or 7, as higher settings merely increase noise without improving power or tone."
     
  14. Masher88

    Masher88 Believe in absurdities and you commit atrocities

    May 7, 2005
    Cleveland, OH
    -1 cable from your bass guitar into input 1 (make sure it's a good cable)

    And set the rest of the amp like in the picture (EQ is ON and No "shifts" are pulled out)

    This is exactly how my amp was running with a G&L L-2000 bass or a EBMM Sterling (both active 9 volt basses). There was never any distortion...just loud as hell and clean. This was with a Schroeder 310212 or an Ampeg 8x10 cab (both 4 ohms).

    Your cabinet (Eden 410xlt) is listed as 4 or 8 ohms (you didn't specify which ohms you have). Make sure you are plugged into the correct jack on the Mesa. That would be the bottom Left jacks for a 4 ohm cab or Bottom Right for 8 ohms. The Top jacks are for 2 ohm cabs. Also, make sure that you cabinet cable is a decent "speaker" cable...not an "instrument" cable.

    If you do all this and you still get distortion...Either your bass is screwed up, (which I assumed that you tried a different bass on the rig...) or that the amps are screwed up (lightning can stike twice!).

    Good Luck and I hope this helps
     
  15. mactac

    mactac Supporting Member

    Nov 28, 2005
    Victoria, BC, Canada
    >Despite your assertions that its the poweramp which is distorting, which I doubt...but that's just me, have you TRIED running the channels a bit lower?

    arrrgh! :)
    YES. the POWERAMP is distorting. I've been playing bass for 15 yrs & also have been producing for 10... the input gain is set below the distortion point. I know how to set gain on an amp :)
     
  16. mactac

    mactac Supporting Member

    Nov 28, 2005
    Victoria, BC, Canada
    sorry, the POWERAMP or the SPEAKERS are distorting... it's NOT the preamp.
     
  17. cheezewiz

    cheezewiz

    Mar 27, 2002
    Ohio

    I'm Definitely not going to get into a peeing contest with you. OK..its the poweramp. I guess you got two in a row that needed a retube. You know, most of the guys on this thread are just trying to help you. If you keep coming back at everyone with attitude, I'd guess you'll be on your own trying to find a solution very soon. (BTW, I've been playing 27 years, not that that makes any difference, because it doesn't)
     
  18. mactac

    mactac Supporting Member

    Nov 28, 2005
    Victoria, BC, Canada
    I'm beginning to think that this is the speakers.....

    tho i've run an eden amp into these same speakers without this problem...
     
  19. Masher88

    Masher88 Believe in absurdities and you commit atrocities

    May 7, 2005
    Cleveland, OH
    It's very possible that whatever cabs you are using...they just can't handle the Holy Terror of Power coming from the Boogie! I remember that I tried out an SWR 6x10 rated for 1000 watts with the Mesa 400+. It was farting out (badly) at relatively low levels. Too low for my needs. that's why I ended up with the 8x10 SVT cab. It could handle the juice! Sometimes, I think, the rating on the back of some manuf. cabs is a touch...shall we say..."inflated"??:eyebrow:
     
  20. Rockbobmel

    Rockbobmel Supporting Member

    Check your battery in your bass. Make sure the effects blend and slave out in the back is off- 0.

    Channel 1 is cleaner and you can get more undistorted volume in it. I have used the 400+ through the D-410XLT and loved it.!! Plenty ballsy.

    Also, I had a few tubes short out and the bottom dropped out. Have your power tubes checked.