Need help w/ burning smell coming from my cab

Discussion in 'Amps and Cabs [BG]' started by duke_togo, Nov 18, 2016.


  1. duke_togo

    duke_togo

    Sep 20, 2015
    I recently bought a used GK 800rb. The 8ohm output does not work but the 4ohm does. I've paired it with a Avatar 2x12 with 4ohm neodymium speakers that I believe are 500w. I was surprised at how low the volume was during band practice as the drummer and guitarist were having a hard time hearing me, I usually have the Vol knob at 2-3 o clock and all the tone controls at around 12. After a few jam sessions I noticed a subtle burning smell in the room and it seemed to be coming from the cab. There was no sign of smoke and the cab is still working but I decided to stop using it to avoid potential further damage.

    My question is how this might have happened if the GK is supposed to be 350w at 4ohms and the Avatar is 500w at 4ohms? Does the burning smell mean the cab is definitely damaged? I play pretty noisey punk/metal music and effects wise I am mainly using a RAT pedal for distortion with bass chorus on occassion and a Fairfield Overdrive Pedal for extra gain.

    Would also love some suggestions on a good cab to pair with the GK 800rb, space is limited in our band's van so something like a 4x10 1x15 or 2x12 are ideal and I'm hoping to spend less than $1000.

    Thanks
     
  2. lz4005

    lz4005

    Oct 22, 2013
    So you have a used head with one of its two power amp outputs dead and it was barely audible and you smelled smoke, but you think the cab is the problem?
     
    Lobster11, SunnBass, ficelles and 4 others like this.
  3. Robroy

    Robroy Guest

    Jun 21, 2006
    You bought a used amp that you knew was defective and found out it was even ore defective than you thought. That's only a statement of opinion. The three compelling facts:

    1. 8 ohm out didn't work. At all.
    2. Seems quieter than it should
    3. Smells like burning electronics (I assume)

    If it were me I'd toss it and get another amp, unless you think it's worth paying to have it come up to full spec.
     
  4. duke_togo

    duke_togo

    Sep 20, 2015
    I am obviously not very tech saavy. I just assumed it was the cab bc thats where the source of the burning smell was from. I didnt realize the 8ohm output was not functional when I bought it as they didnt mention this at the store, then when I got home I noticed a sticker saying "Only use 4ohms" kind of my fault for not checking.
     
  5. BassmanPaul

    BassmanPaul Inactive

    If you have a DC voltmeter set on 200V range, measure the voltage across the Low amp’s terminals with no cabinet connected. I’ll bet you get more than zero volts which is what you should read.

    Just for information, the 4Ω output is the Low amp. The 8Ω out is the High amp. Usually if this is dead the whole amp is so. Often the high amp fails ‘cos the user mistakenly connects a 4Ω load.

    You need to have the amp looked at by a reputable service guy.

    Edit: In the meantime do not connect your cabinet again until this issue is resolved. If I am correct in my thinking, you are needlessly stressing the drivers in your cabinet.
     
    Last edited: Nov 18, 2016
  6. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    An 800RB is the "Chevy 350" of modern era amps. Any amp tech should be able to give it a thorough once over. I would get the head to the shop before we proceed. The cab is likely not the problem.
     
    seang15 and SunnBass like this.
  7. organworthyplayer337

    organworthyplayer337 Professional Hack

    Oct 28, 2014
    Charlotte, NC
    Well... are you in the Charlotte area?




    :roflmao:
     
  8. Bodeanly

    Bodeanly

    Mar 20, 2015
    Chicago
    Man, I'm pretty frugal, but I'll never knowingly plug into a defective piece of gear.

    That said, haul your cab to a tech, have them run a decent amp into it, leave with actual answers instead of speculation, sell the faulty amp for parts, save for a bit and get something legit.
     
    Hoochie Coochie Man and Linnin like this.
  9. Jaco who?

    Jaco who?

    May 20, 2008
    If you've got a 4Ω Avatar 2x12, each speaker can't be 4Ω. If they are, you have an 8Ω cab. Avatar wires them in series because they also sell a 4Ω 1x12. The 800RB 4Ω output is 300 watts, and 200 watts at 8. GK watts tend to be louder than some, but it might explain why you aren't loud enough. That said, I'd get the amp looked at - as common as that amp is, it shouldn't be hard to find a tech who's fixed a few of those 100 watt sections before. It's a pretty common user error.
     
  10. BadExample

    BadExample

    Jan 21, 2016
    Injiana
    Wait, what? You bought it at a store and they knew it was defective but didn't disclose this before the sale? Unless it was clearly an as is sale, it should be fully operational when you get it home. If they say there is no warranty, you should google your state and implied warranty and find out if that's legal. Unless the receipt says as is on it, they are probably liable. They would clearly be liable by Indiana law, and you would be able to collect damages times 3 quite easily in small claims court. That would include what you paid, damage to our cab, any fee's involved, etc. I would learn the law and politely bring that up if they say no refunds. You are certainly not required to inspect for an add on label.
     
  11. stacker

    stacker Inactive

    Feb 24, 2010
    scotland
    Sounds more like the output transformer than the cab, no?
     
  12. Dynacord

    Dynacord

    Jan 1, 2005
    May or may not be related but I had something similar happen years ago and it turned out to be a bad crossover in the cabinet. Put out a nasty burned plastic sort of smell.
    I don't know if your cab has a tweeter but, if so, that could be worth checking.
     
  13. bolophonic

    bolophonic

    Dec 10, 2009
    Durham, NC
    I could smell the cab burning all the way to Person county!
     
    organworthyplayer337 likes this.
  14. Chicory Blue

    Chicory Blue Secretly Queen of the Moon Supporting Member

    Keep it and play it live until it straight-up catches fire. Credit your blazing bass prowess for the kill.

    Flawless victory.

    --^@
     
    SunnBass likes this.
  15. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    Hall! Nope. NC is a bid state East to West. It takes 3 1/2 to get from here to there on a good day. (Used to play 6 nights in a row at the bar in the Holiday Inn on Woodlawn about half a dozen times a year and recorded one CD at Sound House)
     
    organworthyplayer337 likes this.
  16. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Except that there is no output transformer in the amp...
     
  17. wmhill

    wmhill

    Aug 20, 2012
    upstate NY
    MTD basses endorsed artist Bartolini pickups emerging artist TECAMP bass players gear endorsed
    I had a brief affair with a GK 1001. I had the same smell from one my SWR cabs (nuked the 15 and the horn diaphragm ). All my ohms were correct, I just ran the amp hard trying to get a tone that I liked (never did find one) and it was more than the cab could stand. It actually cooked the leads from the voice coil to the cone, in two. The second cab lived through it . I don't believe anything was wrong with the amp, I just ran it too heavy for the cab.
     
  18. nbsipics

    nbsipics Ours' is the only Reality of Consequence Gold Supporting Member

    Apr 8, 2016
    I'm coming over to do some grilling :)

    upload_2016-11-19_12-32-7.png

    Smells are a lot more-likely coming from the amp, not the cab. Unless you are playing at vol 12.5, in which case it's probably both.

    If the amp has a fan, does it work? If you turn out the room lights do you see things glowing inside the amp that probably should not be glowing?

    I also say this a lot to folks: Put a $ value to your time. Buying a marginal piece of gear to save a few
    bucks might cost you a lot more than you bargained-for, especially if you look at the time spent to resolve the issue,
    and especially if that thing really DOES become a dog grill! :)

    I do wish you the very best of luck with that problem.
     
  19. fhm555

    fhm555 So FOS my eyes are brown Supporting Member

    Feb 16, 2011
    We had a sub guitar player once who borrowed an old GK combo amp to use for the job.

    About halfway through the first set actual smoke started to rise from the amp along with a nasty smell but kept going so we finished the set. On break we got a close look and the amp guts were matted with a mix of dust, cat hair, and some kind of sticky gunk like a long ago spilled beer or something, all of which had started to burn when the amp was pushed hard and got hot. We didn't have any other choice so we went on and it worked the rest of the night, but the stink was pretty rank.
     
    wmhill likes this.
  20. duke_togo

    duke_togo

    Sep 20, 2015
    Thanks for all the tips everyone going to have a tech from the place I bought it (Paul's Boutique in Toronto) have a look at it this week and hopefully they will figure it out.
     
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