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MarkBass F1 Quit Temp on me last night

Discussion in 'Amps and Cabs [BG]' started by musicman7722, Mar 9, 2008.

  1. Has this happened to anybody with a F1 amp? I'm not a slapper but I do the occasional pull up slap on the G string. so last night I went for a quick one and the amp just quit playing. The light was and when I pulled the plug from my bass there was not signal. I was singing so I had to finish the song with no bass. When the song ended I engaged my tuner and it indicated the guitar was sending a sig. I powered off the F! and turned it on and bingo I was playing again. I checked the fan for celarance and noise and the unit for heat and didn't hear, see or feel any indications of a thermal. I'm nervous. This was a brand new out of the box from GC that very afternoon. GC to stage. I did a lot of extra slaps after that to try to replicate it. No luck. Now I'm real nervouse. Any thoughts out there? As an asside the band said it was pretty thin with no bass, so I guesse it's nice to missed :hyper:
  2. fenderhutz

    fenderhutz Supporting Member

    Jan 28, 2007
    Harpers Ferry WV
    That sounds like the thermal protection coming on to me. Power cycling reset the amp, finishing the song let it cool down.
  3. I do agree with you.
  4. Ben Rolston

    Ben Rolston Supporting Member

    Aug 30, 2006
    Ann Arbor, MI, USA
    I think that this is the main thing people were worried about with switching power amps.
  5. stingray56funk

    stingray56funk Supporting Member

    Feb 16, 2005
    What ohms are you running it at?
  6. 4 ohms, 2 8 ohm Avatar Cabs, 2 x10 and 1 x 12
  7. hasbeen

    hasbeen Commercial User

    Sep 23, 2004
    Vice President, KMC Music. Warwick U.S. distribution, Ampeg distribution

    I wasn't aware people were worried about that. They tend to run quite cool.
  8. emjazz

    emjazz Supporting Member

    Feb 23, 2003
    Brooklyn, NY
    This has happened to me with my LMII, but I'm sure for my amp it was because I was playing a club's shoddy cab and I'm not sure what the ohmage was. It happened once after that with my own speakers and hasn't happened since. I'm going to have it checked out just to make sure it doesn't happen again. I'm praying it's something that can be easily fixed.
  9. emjazz

    emjazz Supporting Member

    Feb 23, 2003
    Brooklyn, NY
    I have never heard such a claim.
  10. greenboy


    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    Uh? Switching power amps have been in use for ages in sound reinforcement and I don't see anything GENERALLY that makes designs using them any more prone to thermal shutdown than designs not using them. I hope we won't also think this has something to do with Class D or Class H or whatever as the topic goes forward ; }

    As always, it comes down to specific designs and implimentations. But one anecdotal instance if verified as being a thermal shutdown does not make for evidence of either a bad design, or a general condemnation of SMPS. Surely you are aware that amps of all types have at least some owners who have had problems?
  11. youngs


    Apr 7, 2007
    Boston MA
    Happened to me , too. But it wat too warm inside of the club , and I was using Epi UL112 , UL110(so it's 4 ohm)

    So I thought it's overheated , but after that it never happened again. Is this common issue?
  12. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    Something like this has happened to me twice, with different amps. One was a Crate Power Block. The other was a Class-D module built from a kit. In both cases the amp cut out when I played a really loud note while driving the minimum rated impedance. In the case of the DIY amp, I confirmed that I had exceeded the current limit trip point designed into the circuit. I guess the same thing happened with the Crate. The DIY module had to be power-cycled to reboot it. The Crate head came back up after a few seconds of silence.

    Now I have to say that in both cases I was pushing these amps beyond reasonable distortion, at home, to see what would happen.

    Both of these amps ran cool through my torture tests.

    And none of this tells us how the F1 is configured, of course. But a temporary shutdown may be the amp's way of telling you that you are pushing too hard.
  13. This was my first gig with the F!. I have been using a LMII for 2 months and that never happened. The LMII is going back as every so often it will not work with 2 cabinets plugged in. MB tech support just said take it back and get a new one. Of course my GC never seems to have new one in a box and this LMII was a floor model. Oh the Pain.
  14. Hold on... are you saying the same thing happens with your LMII with two cabs? If that's the case (I've been POUNDING both an F1 and LMII into a 4ohm cab at high volumes for many, many, many gigs without a shut-down), then you might actually have an impedance issue.

    There have been comments of these amps shutting down (at least the LMII) briefly in thermal protect mode when run slightly under 4ohms (like with the EA NL-210's, that have a nominal impedance significantly under 8ohms). I wonder if your 210 is slightly under 8 ohm nominal impedance, resulting in the amp running at slightly under 4ohms. If that's the case, and you are also really pumpin', it seems you might have an issue.

    That being said, you might as well swap it out for a new one... if it happens again, then you might have to decide between the head and the cabs.
  15. sounds like a perfect time to double hand grip the mic!
  16. Once more I find myself agreeing with Ken. Take the amp back and get a new one. I would do this if anything I bought stopped working on the day I bought it. I too am suspicious about your speakers. If the problem reoccurs with the new amp get new speakers. Is it me or does there seem to be a lot of problems with Mark Bass amps lately??

  17. fenderhutz

    fenderhutz Supporting Member

    Jan 28, 2007
    Harpers Ferry WV

    With any product you see more complaints than you do praise most of the time.
  18. +1.. and with the HUGE number of these sold, there seems to be very few issues:bassist: However, it seems these heads might be quite sensitive to 'under 4ohm operation'... even if it's just slightly under 4ohms. This does seem to be an issue if you are combining different cabs, since sometimes the nominal impedance can fall under 4ohms.

    I've pushed my F1 and LMII to full output over many hours of playing with the 4ohm 410UL without it ever thinking about a safety shut-down. However, those that have used the LMII with the under 8ohm nominal impedance NL-210's have had these issues.

    I wonder if the OP's combined cabs are somehow under 4ohms?
  19. This only happened with the F1. The LMII Issue I had was that it wouldn't run 2 cabs. Now both of these cabs are quite new Avatar and I wouldn't think Dave at Avatar would let one slip out with a miss marked ohm rateing. SHOULD I should get out my ohmeter?
  20. Certainly you do. It just seems to happen a lot recently is all. I have never seen one in real life let alone played through one. I like the idea of light weight amps, I'm an old fart after all, but all MB amps seem to have a lot of tone shaping that I am simply not interested in. Maybe I should try and find one and become "converted". :)


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