1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

GK observations - 2001RBII, 800RB, 700RBII

Discussion in 'Amps and Cabs [BG]' started by JGR, Aug 16, 2007.

  1. JGR

    JGR The "G" is for Gustav Commercial User

    Jun 29, 2006
    President, CEO, CFO, CIO, Chief Engineer, Technician, Janitor - Reiner Amplification
    I was doing a comparison the other day of the 2001, 800, and 700 at my local store and was actually suprised at the tonal differences between these three heads. While they all have the trademark GK sound, there really are some distinct differences in the overall tones. Aside from the obvious power differences, I found them all to have different gain structures which have a big impact on the sound.. more on this below.

    I played the heads through an Ampeg PR-410 HLF (4 ohms, 600 watts RMS), the new GK RBX 210/115 stack, and the GK 410RBH (8 ohms). Basses were a Thunderbird IV, PRS jazz, and a EBMM H/S.

    First off the 800RB - wow, never played one of these before and I can see why it is a classic. Powerwise, it has to be THE most underrated amp out there. It's louder than a lot of amps I've payed rated at 2x power or more (like the 1000 watt Ampeg sitting next to it :eek: ). Even runnning into the 8 ohm GK410 where it is supposedly only putting out 200 watts, it cranked. I really love the voicing of this head - I found it to have the most useable gain structure of the three - the preamp seems cleaner and doesn't overdrive as quickly as the other two, which I like - it allowed me to get more growl by cranking the boost and the master volume without things getting mushy. I know it has less low end, but I didn't find it to be lacking - perhaps that is what I like as the mids really come through. Great sound for us pic players. I played around with the voicing filters but ended up leaving them all off. I found the amp really easy to dial in and the best tones come from cranking up the boost and master volume a bit to really get some growl going - its a bit dry sounding at lower volumes.

    2001RB - what a beast. Stupid amounts of power. I ran it bridged and made sure the level control on the back was cranked to get full power. I wanted to turn up so bad but this thing has to be the loudest amp on the market right now, regardless of what other amps claim for power. It has such a massive underlying low end girth from all of the power waiting to be unleased - this amp seems capable of blowing speakers quite easily. It was really easy to drive the hell out of the Ampeg and GK alike - this amp really gets the speakers MOVING! I found this amp to have the hottest preamp gain structure - I really had to watch the input gain and keep it low to keep things from getting too overdriven and mushy. I had the best results using the -14 db pad which allowed me to crank the boost and power section more to get the growl without it being too overdriven. I wish the input gain wasn't so hot though - I prefer the gain structure of the 800RB which seems more forgiving. I want this amp though for the stupid power it puts out.

    Finally, the 700RB - they didn't have a 1001RB. Nice amp and seems to be in between the other two in terms of gain structure. Hotter than the 800 but not as hot as the 2001. Plenty of power but tonewise, there is a certain character, vibe, mojo - whatever - with the 800 that I like better. I know you can get a close approximation, but I don't think you can cop it exactly, and I'm glad GK still makes this amp. Don't overlook it.

    Cab wise, the Ampeg and GK410 sounded great and handled the power well (though I think the 2001 could destroy them :eek: if cranked!) I played around with the tweeter/biamp on the Gk410 and it works well though I don't think I would use it ( I hate tweeters). The new RBX stack was alright - I like the fact that there are no tweeters, but they seem like they would strain at higher volumes, and there was nothing special about the tone that would make me pic them over someting else.

    In closing, all cool amps. I want an 800RB and 2001RBII.

    I'd like to hear more on folk's experiences with the 800RB - I think it has a really unique tone that may too often get overlooked now with the 1001RB being at the same price point (though I understand while most folks may choose the 1001 over the 800). I'd also like to know more about the build of quality of the 800 - is there more work involved or more expensive compenents that raise its price point compared to the 700/1001?


  2. morebass!

    morebass! I'm all ears Supporting Member

    May 31, 2002
    Madison WI
    Thanks for the review. I've owned 800RBs and now own a 1001RB2 but not at the same time. Sometimes I think I liked the 800 better but it's been a while... Now you've got me thinking maybe it was better.

    Was the 700 louder than the 800?
  3. JGR

    JGR The "G" is for Gustav Commercial User

    Jun 29, 2006
    President, CEO, CFO, CIO, Chief Engineer, Technician, Janitor - Reiner Amplification
    I didn't find the 700 to be louder - I would imagine there wouldn't be much of a noticeable difference other than a bit more headroom at the upper limits.

  4. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    I've used both the 800 and 1001 RB II. The more sophisitcated pre in the 1001 RB II takes longer to dial in. I can sound pretty much exactly like the 800 though.

    In GK - the 1001 RB II would be my pick.
  5. v-12


    Mar 3, 2005
    FL Panhandle
    how would you compare the available power of the 2001rb to one of your db728's?
  6. JGR

    JGR The "G" is for Gustav Commercial User

    Jun 29, 2006
    President, CEO, CFO, CIO, Chief Engineer, Technician, Janitor - Reiner Amplification
    even the mighty DB728's are not going to be able to match the 2001RB's output IME, at least not while staying clean and tight in the low end.... but now we are talking about some serious, crushing, stupidly loud levels :eek: (which i love):)

  7. chiplexic


    Apr 21, 2004
    I've got a 400rb I bought back in 1988. It was acting a little funky (no it wasn't the whole return jack thing). So I got a Peavey 700 head to use in the mean time. That Peavey wore on me quickly so I found a trick to get the GK running. When I finally got it fired up again I really had a new found appreciation for it's tone. I imagine it shares a lot of the old 800 rb pre-amp parts.

    Even still today. The only way I can keep the 400rb running right is to keep it plugged into and AC outlet all the time. As soon as it is unplugged for a while it comes back at a staticy half volume, cutting in and out. That means it always has to stay at home. Bums me out. And I only got about 20 years out of it.;) I've considered the LittleMark II to replace it but as I've said before...I don't like the thought of having to deal with Guitar Center for parts and repairs after the 2 year warranty is up on the LM II. What a nightmare that is shaping up to be. A 1001rbII is looking good right now. I think it is an overlooked amp mainly due to it being looked at as too common (yesterdays news). Many want the next best thing.
  8. 62bass


    Apr 3, 2005
    I owned a 400 RB for about 10 years, played live a number of times through the 800 RB and owned the 2000RB (forerunner of the 2001 RB) for several years. I liked them all. They may have all sounded different with different gain characteristics but in practice it made no real difference. Just a quick tweak and I had the sound I wanted. They all seemed to have a lot more power than their power ratings would suggest and even the 400 RB into an 8 ohm load was surprisingly loud. I preferred running the 800 RB in mono mode when I was using it with Ampeg 4x10 and 2x10 cabinets together. I used the 4x10 in the main 300 watt amp and the 2x10 in the 100 watt amp. Just sounded a bit meatier than it did bi-amped. The 2000RB had seemingly unlimited power. All that reserve power did seem to make the bottom end more solid at higher volumes even if I wasn't playing any louder than I did with the 400 RB. And very reliable amps. The 400 RB is still being played live every weekend 6 years after I sold it to a local player. He loves it driving a home made JBL D140 loaded cabinet. I've heard him play on a gig with it and he gets that perfect 60s era bass sound.

    I've tried the 700 RB and 1001 RB in stores and they sound very good. I don't know which one I'd choose if I were to buy one or if I'd stick with an 800 RB. The only fault I can find with the 800 I used and my old 400 RB was the fixed contour control. It's nice sometimes to bring in just a hint of that scooped midrange.

    GK makes excellent amps.
  9. RBasss


    Dec 13, 2006
    Richmond, VA
    East Coast Sales Coordinator - Crafter Guitars
    I had a 1001RB-II for a while. It had plenty of power and was very reliable but always sounded a bit sterile to me. I'm playing an all tube amp now which is great but I know eventually I'm going to need to get a back-up just in case (you never know with tube amps). It sounds like the 800RB might be a good one to look at for this. I imagine it can drive an 8x10 pretty well.
  10. metron

    metron Supporting Member

    Sep 12, 2003
    I have a 1001RB-II and like it a lot. I have wondered about an 800RB. People seem to love them but I have never tried one. The previous bass player in my band used one with a Hartke 115 and I thought his tone was amazing.

    4mal - how do you set the 1001 to get the 800 tone?
  11. JKT


    Apr 30, 2007
    Buffalo NY
    Endorsing Artist: Barker Basses
    I use a 700 in a church setting every Sunday but set the input and boost just like my 1001 That I use for everything else.

    The 2 amps sound somewhat different but I have always wondered how much is the acoustices in the church. Ihave been meaning to haul in the 1001 one day and compare them.

    I sometimes think that the 700 has a somewhat warmer sound than the 1001 but I wouldn't ever give it up.

    For all my applications I have yet to run out of headroom with the 1001. I sometimes run another cab for bigger shows.

    I love the 700watts...

    JKT :bassist:
  12. chiplexic


    Apr 21, 2004
    As a rule of thumb - I used my (200w @ 4ohms) 400rb to power a 1971 SVT 8x10 cab for years,on all size stages ,and it was plenty of power to make that cab perform it's thing.

    As far as the tone differences between 700rb and 1001rb.
    I really think my days of needing the power of a 1001 are over (460@8 and 700@4 ohms). But I have pondered still getting it over the 700 just to assure clean headroom. However if the 700rb is considered warmer then I may opt for that head instead (320w @8 and 460w @4ohms). I can't imagine I'd need more than that especially given the modest GK power ratings.

    Bob Gallien has stated the 700rb acheives the GK grit easier than the 1001rb. I assume since it has less headroom.
    Maybe the perception of warmth is actually that grit showing thru?
  13. Kenny Allyn

    Kenny Allyn

    Mar 25, 2006
    I have a 1001RB that I aquired recently and a 400RB that I've had for years and they are very different ...

    The 400RB is almost tube warm when compared to the 1001 and both seem to have more than their rated power.

    I bought the 400RB when I sat in at a blues club one nite and the bass player had one with some old 1x15 cab, man with a P-bass it was just heaven ... I bought an old Carvin RL115 cab too. Still have both the amp and cab oh and the P-bass too.

    :smug: ... I have been a longtime GK fan.
  14. wingnut


    Apr 18, 2007
    Las Vegas Nv.
    I played a GK800RB for twenty years with not one single problem. I used a trace elliott 210 as my main cab. Then I switched to URB almost exclusively. I THOUGHT I needed more watts, so I traded off the 800 for the 1001RBII. I really think if I had it to do over, I would keep the 800 and would have changed speakers. I ended up getting rid of the 1001 for a pair of Mark Bass LMII's.
  15. Here's a quote from him on this topic:

    "When a power amp puts out as much power as it is capable of producing, that is referred to as "hitting the rails." The way our amps go in and out of the rails is very different to how other manufacturer's amps react. Sometimes you will hear guys talk about "the G-K growl." If a bassist is used to playing an 800RB, he'll know exactly where he needs to place the controls on his amp to get that G-K growl. If he then moves to the 1001RB-II which puts out over twice as much power as the 800RB, he'll have to play his amp much louder to get that same type of growl. I have found that this is one of the biggest things that bassists have to learn in moving to a more powerful amplifier. If you want to maintain the classic G-K growl and don't need to play at loud volumes, then you definitely want to stick with a lower powered amplifier so it is easier for you to hit the rails."

    If I had known this before getting the 1001RBII, I might have gotten the 800. I don't know if I'll ever need all the power. And I'd like to get more growl without blowing my walls out sometimes. Maybe I should get a 400...

    Entire interview found at
  16. shoot-r


    May 26, 2007
    I love my very-very old, GK800RB.
  17. chiplexic


    Apr 21, 2004
    Some great comments from Dan Elliott of G-K talking about the Series II heads just before release. 4/2003

    "This is a follow up to another thread, but I can't remember which one so I'm starting a new one. I did a comparison between the GK 700RB, the 1001RB, and the 2001RB. These were the pre production lab units of the upgraded models. Tomorrow, I'll compare the current 700RB to the 1001RB.

    The reason for this test was that we had reports that the 700RB was warmer than the 1001RB. That may still be true with the current model, but with the new ones, this was my finding.

    First I compared the 1001 and the 700. Once I got the volume between the two about even, I could not tell a difference between them at low to moderate levels. At high levels, I could guess the amp I was playing through about 60% of the time. The 700 had a slight loss in the high frequencies with a slight bump in the lows. It was really difficult to tell the difference.

    Next, I compared the 700 to one channel of the 2001. In this case i had a much more difficult time picking the amp I was hearing in the blind test, but ultimately found the same thing as with the 1001.

    Our theory is that with the 700 you're hitting the rails at a lower volume producing a "stressed amp" sound that could be construed as "warmer". I was able to produce the same kind of tone with the 1001 and 2001, but at higher volumes.
    In the end, the tonal differences were so minute even at high volumes, that I could not truely say that one amp was warmer than the other. So that's my findings. I'll let you know about the older amps tomorrow."

    Great info from the company themselves. Guess I had the name of person I was quoting wrong in my first post. It makes me want to try all their amps! But it does make me think the 700rb could be a lot of fun given the different characteristics it shows at different "usable" volumes. I don't think I'd ever have the 1001rb loud enough to see it perform the same way as the 700rb does at high volume. Hhhmmmm....However head room is addicting.
  18. jarrod cunningham

    jarrod cunningham

    Apr 24, 2007
    sylacauga alabama
    spector basses
    using my gk800rb( early 80's) with my early 70's square back ampeg 810(new speakers) and its amazing !!! i sold my 76 svt head on evilbay and have never regretted it at all .... i play anywhere from 150 seaters to a 1500 seater and never need more STAGE volume .... love it will never sale it , if it dies ill buy another !!!!
  19. JanusZarate

    JanusZarate Low End Avenger

    Feb 21, 2006
    Petaluma, CA, USA
    In an interview with Dave Ellefson (former longtime bassist of Megadeth) I read a while back, he talked a bit about his original rig from the 1980s:

    Go figure. Pick + GK (I'm presuming it had to be the 800RB) = :bassist:

    There's an incredible amount of power and definition to be had with GK heads... it's why I love my 2001RB!
  20. Hey just a quick clarification. The RBX series has tweeters in it. If you had a stack there with no tweeters it was the BLX series. You may have been confused because we removed the lame BLX grafitti logo from the grill. Another way to tell is the RBX is taller than it is wider because of porting whereas the BLX is exactly square.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.