Boost knob on the GK800RB

Discussion in 'Amps and Cabs [BG]' started by UnDoNe, Nov 12, 2012.

  1. UnDoNe


    Dec 6, 2002
    Hi all,

    I've got a GK 800rb but the boost knob seems to hardly make any difference at all. Whether the boost is on full, rolled back or turned off completely, it all sounds the same. Is it quite a 'tame' change to the sound or should I definitely be hearing something? Thanks in advance folks
  2. Hi There,
    You should certainly be able to hear a bump in volume. Check to see if the green light next to the boost knob (red light on older models?) is lit. If not you will need to use a footswitch (any single function pedal should work) to turn the boost on/ off. This has actually been a request on some of the newer RB series heads to have the boost footswitchable. Hope this helps,
  3. It's subtle especially at low volumes, but as you get louder and increase it you'll start to notice the 'GK grind.' It adds upper harmonics and a very small amount of distortion.
  4. ThisBass


    Aug 29, 2012
    The GK boost does never make an audible clipping.
    Even in the cranked position the sound remains "audible clean"
    Hope that helps.
  5. UnDoNe


    Dec 6, 2002
    Thanks everyone for your replies. I don't get much chance to crank it, but I've got practice at the weekend so will try it out then.
  6. Energy


    Jun 20, 2006
    How do you set the gain knob on your 800rb?
    The boost depends on the gain setting. The higher the gain, the more effective is the boost knob.
    For my passive basses, I set the gain at ~1 hrs on my 1st series 400rb. The influence of the boost is huge: it first adds more volume (lots of it), and at ~1 hrs is where that famous GK growl kicks in.
  7. Wally Malone

    Wally Malone

    Mar 9, 2001
    Boulder Creek, CA
    AFM International Representative Endorsing Artist: Accugroove Cabinets & MJC Ironworks Strings
    I set the master volume at full and then adjust the input gain. Once I find what I'm looking for and want a little more of what I already have I then use the boost.

  8. will33


    May 22, 2006
    This ^^

    Run your input up to a good noon - 1:00 and the boost will come alive. Then use the Master to set overall volume level. These are one of few solidstate amps that sound good when you crank them. If you find yourself in a situation where it's volume appropriate to run the master up to 3:00 or so on top of all that it gets extra fun. I've been using my 400rb on more and more smaller gigs so I can do just that. But, the 800 too will get you that sound at appropriate volume if you set the input higher. Use the master as the volume knob.
  9. UnDoNe


    Dec 6, 2002
    Sorry for the delay in getting back to you guys. Thanks very much for this, I keep my volume on full and turn use the gain as a 'volume', so I'll try it the other way round tonight. Never thought of trying it the other way if I'm honest!

    Thanks again
  10. I just picked up a "like new" 800RB off ebay. I can't wait to try it out!
  11. The other way round works much, much better.
  12. IPYF


    Mar 31, 2011
    Heavens. A GK Master Volume set to full??? Really???

    I have a 1001 and admittedly it has a much higher wattage rating. I've never had this head past 11 o clock on the input, master and boost. Running padded I'm still wailing on two 120w tube guitar heads in the mix with an 8ohm cab.

    I love the boost function when used in conjunction with the Contour. I set my contour and presence really hot (around 2 o clock) with the 5 string setting and I find that the boost really pulls out the hair on the low mids when run between 10 oclock and 11.
  13. UnDoNe


    Dec 6, 2002
    IPYF - Volume was on full, but gain was used to control actual output :)

    Anyways, I tried it the other way round, gain on 3-oclock, boost on full and using master volume as...well, volume! First impressons was that it was a lot bassier doing it this way and just felt a bit thicker i sound. Overall, liked it very much...thanks for the tips folks.
  14. Hmmm... maybe stupid suggestion and also the question ... in the boost section (under the boost pot) the green led lights up? if not - the boost is off.
  15. Dave W

    Dave W Supporting Member

    Mar 1, 2007
    White Plains
    Yep, exactly. On older models its red...
  16. UnDoNe


    Dec 6, 2002
    Definitely on :)