2 New Defective GK MB Amps in a row - What now

Discussion in 'Amps [BG]' started by Jim C, Apr 15, 2014.

  1. Jim C

    Jim C Spector#496:More curves than Sophia + better sound Supporting Member

    Nov 29, 2008
    Ordered a MB500 - LOVED the tone but it had a defective mute switch
    Sent back on my dime ($21.75) and added additional monies for a new MB800;LOVE the tone and power

    This one has two problems
    * You have to push the gain B knob in just the right place for it to switch channels (the back side of the knob opposite the indicator); the A gain works perfectly
    * The master volume is supposed to be a push switch to defeat the limiter; this pot does not move (either in or out)
    I doubt that I will ever use this feature but fear the pot may have problems in the future as the push function does not work

    It is clear the pots are a bit sloppy in that they will wiggle when turned gently. I assume they were chosen for size and price but expect a pro amp to be a bit more precision.

    The last thing is the QC that has not ben performed when the amps left the factory; the above happened right out of the factory sealed carton on both units.

    Anybody else have this issue?
    Is it worth trying one more time?
    Ironic that the tone is perfect yet the controls have not been right on the 2 I've had.

    If anybody from GK sees this post; HELP!

    PS - I bought an ancient 400RB (attached power cord) just to compare the tone to the 500; it sounded great and very close.
    Ironically this amp is quite old, a bit beat up. yet the controls all work fine.
  2. Frustration! !! 😈😈😈
    Can't help ya Jim. But feel your pain mate. I'd replace if that was a possibility-financially and practically.
    Goodluck. 👍👍
  3. RockDoc


    Jan 5, 2007
  4. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    pm Rag and see if he can help you out?
  5. Sponsored by:

  6. emblymouse

    emblymouse Supporting Member

    Jan 22, 2006
    W' Sconsin
    Endorsing Artist Lakland**Bag End**Schroeder
    I returned a MB500 for much the same reason. It sounded great but I was afraid the knobs would fall off. I'd almost talked myself into trying one again but your post has slapped some sense into me. I think I will go for a Puma. ;)
  7. Hi Jim,

    Out of curiosity - did the two amps come in factory sealed or re-sealed boxes and were both amps purchased from the same dealer, and if so, which dealer was it? Thanks

    EDIT: Oh, and how long ago did this happen - when did you return the amps? Thanks again.
  8. RockDoc


    Jan 5, 2007
    I was going to ask the same questions that Joe L just asked....
  9. jza57

    jza57 Supporting Member

    I have had good luck with their micro amps but I am just about done with their Neo cabs . Had a bum series 1 Neo112 that GK replaced no questions asked and now about 4 months into a Neo 212 II I have 2 blown drivers . Guess what , new GK rules , you gotta go through a service center and prove you didn't blow it by user error.
    Back to the topic , if you like the GK sound just get a Fusion 550 and call it a day.
  10. Jim C

    Jim C Spector#496:More curves than Sophia + better sound Supporting Member

    Nov 29, 2008
    Both amps came from RMC in factory cartons
    MB500 was 2 weeks ago
    MB800 was yesterday

    Thanks for the knob thread; I'll give it a read
  11. Jim C

    Jim C Spector#496:More curves than Sophia + better sound Supporting Member

    Nov 29, 2008
    I bought them new so no problems with returns.
    Even used the 500 on a gig we play often and didn't touch the mute switch; best sound I have had in this room and this is over a 7-Pro which was bought used and works perfectly.
  12. pfschim

    pfschim Just a Skeleton with a Jazz bass

    Apr 26, 2006
    SF Bay Area
    hey JimC, sorry to hear about your challenges with the GK's.

    If I recall correctly, you have also been a Walkabout user in the past (may you still are ?) Anyway, I am looking at the MB Fusion 800 as a possible way to get more clean volume, and wonder if you can compare the two amps seeing as how you have used them both (I'm going to assume the 500 and 800 are sonically similar)

    very interested.

    hope you figure out the best thing to do.
  13. Thanks Jim, and yeah checkout the knob thread.

    My thought is since you really LOVED the GK MB800, I'd take that one last chance with another one. However this time order it from Sweetwater instead - yeah I know it cost a little more, but the amps may be from different batch runs - and it's the last chance, so don't be cheap.... just saying. Or give up and try something else - either way, I wish you the best.
  14. I would suggest a Genz 9.2 / Max 9.2...but now...they aren't as easy to find.

    I would have tried a GK MB ages ago but these things put me off. Shame really.
  15. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    I had a sticky power switch on my Mb Fusion. Jason turned it around for me in about a week. I did pay to ship it to GK and I didn't involve RMC as we are on different sides of the country. Ii wasn't overly thrilled but... I do really like that amp...
  16. cableguy

    cableguy Supporting Member

    Jun 4, 2009
    North Bend, WA
    Maybe pick up a PF-500.......:eyebrow:

    Even though I had great luck with my PF, I've always had great luck with my GK's. Never had their micros, but the CS has always been stellar. I would send it back to the factory and have it fixed. But 3 strikes and your out, so if it happens again, look to a RB-II series.
  17. will33


    May 22, 2006
    Any chance the serial #'s are close to each other, like maybe a bum production run or something?

    PS...your 400Rb is already small and light....and loud.....and it'll last as long as you do. :)
  18. Hmmm,...and i see this just as I'm getting ready to order an 800 fusion from rmc.....time to drop back, punt, and think it over a bit.....
  19. Tunaman


    Dec 26, 2004
    I remember you debating the shuttle 6.2 deal when i was looking. That thing is built like a tank, its been great! Wish it was a 4 band eq though!
  20. B-string

    B-string Supporting Member

  21. AMp'D.2play

    AMp'D.2play Supporting Member

    Feb 12, 2010
    I received my MB800 2 wks ago, so about a week before you did. Also from RMC. I haven't had any issues yet, but I guess I should run it fully through its paces to make sure everything is ok. It hasn't left the house yet, so I really haven't had to use the limiter on it. Nor the gain B, either. I'll check the buttons on mine tonight, and play it a bit at volume tomorrow just to be sure.