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Durability, warranty on GK MB Fusion 800

Discussion in 'Amps and Cabs [BG]' started by DCGuy, Apr 15, 2016.

  1. DCGuy


    Apr 12, 2016
    Washington DC, USA
    What's your experience with GK MB Fusion 800 head, and hauling it around a bit? Does it hold up? Do you have to worry about replacing tubes or durability in general?
    Many thanks!
  2. been hauling mine around for a year and a half no issues
  3. Same here, no problems
  4. Hand slap

    Hand slap

    Feb 14, 2016
    Looking at buying the MB Fusion 800, currently have a RB1001, Looking for a tube tone, my concern is with the RB, I cannot clip the input, I play hard, and have 2 hot active basses, I have never played through the MB series, to me they look like a toy, I am a big GK fan, had the old RB 800 too. Worried about input clipping, even with the db switch, and more worried about a lack of delivery, at loud volume, for long periods of time. Can the little amp, keep up, and is it everything they say it is? I am apprehensive. Please advise, I would hate to be disappointed.
  5. Hand slap

    Hand slap

    Feb 14, 2016
    Is the amp a road worthy unit, that delivers? Does it have the "stuff" the other Gk amps have.
  6. It is built on the same power amp Bass Gear Magazine tested with the MB800 (non-tube). Their tests revealed better than 800 watts @ 4 ohm and sustained burst power of over 1,000 watts. It delivers. You will have a better experience with the tube preamp than the more limited (input voltage) of the 800RB. It is hard to clip the first stage on the 700/1001RB series. You may get more overdrive "hair" on hard playing with tubes (not what you think of as clipping). The MB800 (non tube) also has the same discrete FET front end as the 700/1001RB series, the MB500 does not.
  7. spanndrew


    Oct 14, 2013
    Atlanta, Ga
    I love mine. It's been super durable during my tenure in a punk band thus far, and trust me it gets rough out there. I've had mine a year, and am not the first owner, no need to change tubes yet.
  8. Hand slap

    Hand slap

    Feb 14, 2016
    Ok, think I'm gonna buy it, they
  9. Hand slap

    Hand slap

    Feb 14, 2016
    Thanks for all the info, sounds like you researched it.
    B-string likes this.
  10. Jim C

    Jim C Is that what you meant to play or is this jazz? Supporting Member

    Nov 29, 2008
    Bethesda, MD
    I don’t think either sound close to my SVT in terms of tube tone.
    I have a Fusion 800 and a 400RB.
    Both are super reliable and the MB is easy on tubes as you would expect since there are no power tubes.

    The RB sounds less hi-fi and more like a 70’s style tone.
    The MB is more modern and can get crazy bright.
    Inspite of the above, they sound more similar than different.
  11. Hand slap

    Hand slap

    Feb 14, 2016

    OK, good to know, I have a 1001, I like it, its punchy, I am looking a getting maybe a "rounder warmer" tube sound, but, dont want to sacrifice "the punch". I am also a tech, and worked on all the product for 30 years, and never have really played through the Ampeg line, to speak of, in fact I have never owned a tube bass amp/, although I do have a Red Head, which is a 1 tube preamp, I bought that for a back up/and I refurbed it.
  12. Hand slap

    Hand slap

    Feb 14, 2016

    Huge GK fan
  13. ArtechnikA

    ArtechnikA I endorsed a check once... Gold Supporting Member

    Feb 24, 2013
    I have a MB500 Fusion which may or may not be similar... I am given to believe the front-end is.
    I was having signal dropout issues (like you might expect from a dirty FX loop switch, which it was not).
    Opened it once to check for loose or bad contacts, moved the tubes to different sockets, reseated the ribbon cables on the tube daughter board, reassembled.
    Worked fine for a few months, then it came back.
    Since it was still under warranty (1 year into the 2 years warranty), rather than just try stuff at random I got a GK RMA and shipped it back.
    Got word yesterday it was a bad tube (all JJ's). It's in burn-in / test and will be shipped back to me tomorrow.

    So there's my answer to your warranty question: GK supports the products.
    I am the original owner so I can't speak to the transferrability of the warranty.
  14. The MB Fusion 500, 800 both share the Fusion 550's full tube preamp. Six section three tube high voltage design. Warranty last I know is not transferable, but that has not stopped G-K from taking care of owners on most occasions.

    JJ is about the most reliable of the new production preamp tubes I have seen, but they are still nowhere near the quality/reliability of the old days.

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