Quasi-Scientific Amp Comparo: Blue Rock, Magellan, GBE 1200, KXB 500

Discussion in 'Amps and Cabs [BG]' started by MarkA, Jun 18, 2016.

  1. MarkA

    MarkA In the doghouse. Supporting Member

    Sep 26, 2008
    Here's the short version:

    I made some clips of four amps: the Genzler Magellan, the Glockenklang Blue Rock, the Genz Benz GBE 1200, and the Kustom KXB 500.

    In this post, I self-indulgently ramble my way through some philosophical considerations and general notes about why I did stuff the way I did. In the next post I give some specific notes on the amps and the recordings. In the post that follows that are the recordings themselves.


    About a year ago, I made a thread with comparison-clips of a several preamps (and the preamp sections of some amps). I learned stuff about gear – and my own tendencies using it – and had some interesting and informative exchanges with TBers. I hope that the people who read the thread found it likewise interesting and useful. It was a cool experience but also, in the end, frustrating for me. Playing the same things over and over, in the musical vacuum of my living room, and obsessively tweaking levels and EQ with each subsequent round of recording, two things happened:

    By the end of the thread, I ended up making everything sound more or less the same. On the one hand, it's good to know that you can get to a lot of the same sonic destinations with different rigs. (As more than one person has said, “I always sound like me, no matter what I play.”) On the other hand, the preamps and amps I played all have distinct personalities – though you can get to similar places with most of them, there are places some will go that others won't, and places that they want to go that vary with each amp... not to anthropomorphize or anything. Many of those differences were lost in the unintended homogenization that went on as the thread progressed.

    Secondly, as much as I obsess about tone (and feel!), and as OCD as I am about gear, “playing gear” (as distinct from “playing music”) or “listening to gear” for any length of time is not what I enjoy. The whole thing started to seem pointless, and my joy in my fancy equipment faded – I became like Gollum, if Gollum were slave, not to a ring, but to a recording interface and several boutique preamps. "I am a tones chaser," but the whole experience was not very metal.


    So, it is with some hesitation that I set out to make a similar thread comparing amps. I did go through a few rounds of recording and fiddling – didn't think to record with the D.I. the first time around, didn't get the levels quite right or like the way I EQed some amps the second time – but kept at least some semblance of control this time.

    I also made some improvements to my methodology based on stuff I learned from the first thread:
    • Every amp is recorded at least four times: Miced and via its D.I., EQed and “flat” (knobs at noon). This offers multiple reference points for each amp and safeguards us against any wacky EQ choices I might have made or bad mic-ing technique I might have employed.
    • Where there was an option to set the D.I. to line level (GBE 1200, Magellan), I did that, as, with those amps, it seemed to result in a cleaner, more dynamic recorded sound.
    • I set the Gain and EQ for each amp with the same general tone/feel goals in mind, but didn't try to force one amp to sound exactly like another – if the bass through Amp A felt bigger or deeper than the bass through Amp B, but chasing that with Amp B made it feel unbalanced, I let Amp B be. (Rimshot!) Conversely, I didn't attenuate the low end of Amp A to try to “bring it in line with” Amp B.
    • I matched levels as closely as I could while recording and normalized before upload (I think I did this the first time, but worth mentioning).
    • After a little research (and uploading some test recordings), I uploaded uncompressed files to Soundcloud. They all get compressed to 128 Kbps mp3 in the end, but not having the files go through the conversion process twice resulted in marginally better sound quality.
    I recorded mic-ed clips because I play through a cab and that's a big part of the feel and the tone. D.I. recordings take the power section – which is important if you're evaluating the amp as a whole – out of the picture. I know that clips can only communicate a fraction of a rig's feel and response, but it's my hope that recording with a mic and cab captures a bit more of it than just taking a signal from the D.I.

    That said, mic-ing is tricky – every little scoot of the mic changes the tone and the feel of the recorded sound – and not everyone is going to play the same cab I do. The D.I. recordings remove those variables from the equation and are included for that reason.

    The mic-ed sound isn't perfect -- it lacks some of the balance and detail I hear from the rig “in real life” -- but it's not too far off the mark. I trust that, with the D.I. clips, it will be enough to give people a fair idea of what's going on.

    More to come.
    Last edited: Jun 18, 2016
  2. MarkA

    MarkA In the doghouse. Supporting Member

    Sep 26, 2008

    I have had the GBE 1200 for a few years now and used it for everything from home practice to funk jams to stupid-loud gigs with 170 pound cabs. I've had the Kustom for a little over a year. It has seen some jams and gigs as well. I liked it enough to keep it while I sold my Markbass F500 and Aguilar Tone Hammer 500 (never really bonded with the Aggie, but the F500 served me well for a good while). I feel that I know the GBE and the Kustom pretty well (though there's always more you can learn). The Blue Rock, especially, and the Magellan are more recent acquisitions -- I am still getting to know them.

    This is an interesting group of amps -- I think that amp sociologists (I minored in Amplifier Sociology*) would find it interesting, anyway. Price-wise, the Magellan sits in the middle, bracketed on one side by the Blue Rock, which sells for twice as much, and on the other by the humble KXB 500, which sold for half as much. The GBE and the Kustom are no longer made, while the Blue Rock and the Magellan are still pretty new on the scene.
    *not technically true

    The GBE is a big, class AB, pro-touring amp and was the flagship of the Genz Benz line. The little Kustom was an econo-entry in the amp game but has turned out to be my favorite of the “500 Watt” micros I've owned. The Blue Rock and the Magellan are aimed, I think, at different but overlapping market segments: They both purport to bring a new level of performance to smaller, lighter bass amps than was commonly available even a few years ago. Can a small amp really perform like a big, transformer-based amp? Do the newer, lightweight amps offer significant improvements in performance over the older ones? The GBE and the Kustom serve as nice landmarks on either end of that particular playground.

    Note: While I have my own, evolving opinions, I don't propose to answer the above questions for you. I will say that these clips do not show how any of these amps behave under duress. I waited until the neighbors were away and played as loudly as I felt comfortable doing in my living room while recording – I wanted the amps and the cab to at least approach a “realistic” dynamic level – but that's still well-short of even a moderate-volume bar gig. Plenty to get you kicked out of most coffee houses, though. ;)


    • The bass is a Fender PowerJazz Bass Special (reverse-P/J) with Wilde pickups and a 3-way pickup selector switch. The strings are... old. The bridge pickup is up full and the neck pickup backed-off just enough to help harmonics come through when both pickups are selected.

    • The cab is a MAS (Michael Arnopol Soundworks) 112 cabinet – the version with the 18Sound woofer – recorded with an Audio Technica AT-2035 condensor mic into a Focusrite Scarlett 2i4 into Garage Band. Mic is about 8” from the grill, slightly off-center from the woofer. No EQ, compression, or other effects are applied to any of the recordings.

    There are 21 clips in total.
    Yep, 21. Nineteen “clean” and two overdriven.

    Each “clean” clip runs through a GM7 arpeggio (both pickups), then some chords with harmonics (bridge pickup), then a palm-muted riff (neck pickup).

    • one “control” clip, with the bass straight into the recording interface.
    • four clips for each amp (six for the GBE*): D.I. flat, Mic+cab flat, D.I. with amp EQ, Mic+cab with amp EQ.
      • For the “EQed” recordings, the GBE has FET and TUBE channels mixed (about 2/3 FET, 1/3 TUBE) and the “LF Extend” (adjustable HPF) rolled down about ¾ of the way (resulting in deeper low-end extension than with it disengaged).
      • For the “Flat” recordings, knobs are at noon. On the Blue Rock, the switchable EQ section is disengaged. *On the GBE, there are two sets of “flat” clips, both using only the FET channel: one with the “LF Extend” in the same position as above, and one with the “LF Extend” disengaged.


    There are two mic-ed, overdriven clips – one each with the Blue Rock and the Magellan. The tweeter is turned off for these. I made these the day before re-recording all the clean clips – no, I don't have D.I. clips for the OD.

    The overdrive clips proceed as follows:
    • Blue Rock: (1) mild (could've been milder) overdrive, (2) a little more overdrive, (3) the same degree of overdrive as (2), but with the VOICE filter engaged at about noon, (4) max overdrive (without "Voice" filter) and finishes with (5) max overdrive (with the "Voice" filter engaged).

    • Magellan: (1) mild overdrive, (2) moderate overdrive, (3) max overdrive, (4) max overdrive with a little "Contour A" (mid-scoop) (5) "" with a little "Contour B" (mid-boost and bass/treble roll-off ) (6) "" with more "Contour A", (7) max overdrive with more "Contour B".

    The clips reflect my playing, instrument, EQ choices, and the circumstances of their recording (solo in a hot living room -- AC and fans off to avoid mic-bleed!). They are not definitive representations of anything, but I hope that they communicate something of the character of each amp (and that the mic-ed clips do the cab some justice).

    Clips to follow.
    Last edited: Jun 18, 2016
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  3. MarkA

    MarkA In the doghouse. Supporting Member

    Sep 26, 2008
    Okay, 21 Clips is a lot to keep track of, so I've organized them into playlists of four to six tracks in what I hope are logical groupings.

    First are the "Flat" D.I. tracks. (Starts with a "straight in" track, recorded direct-to-interface, for a control.) Here "no LFX" means that the "LF Extend" (adjustable HPF) feature for the GBE is disengaged. According to the manual, it should start to roll off at ~45 Hz, set that way. Where it just says "DI Flat" I have a healthy dose of the filter engaged -- not sure exactly where that would roll off, but, being that fully engaged is supposed to roll off at 30 Hz, I'd guess somewhere in the mid-30s Hz. "Sans EQ" (EQ disengaged) is "flat" for the Blue Rock. For everything else, knobs (except for Gain and Master Volume) at noon.

    "Flat" MICED tracks...

    EQed D.I. tracks...

    And the EQed, MICED tracks (the overdriven tracks are at the end of this list)...

    I took some photos of the EQ settings used -- I'll say something about those later.

    Good night, Gracie!

    *From the GBE 1200 manual: The “L.F. EXTEND” (low frequency extend) lowers the low frequency roll-off response of the preamp (between 30 and 45 Hz) to allow the full effect of 5+ string and extended scale instruments.
    Last edited: Jun 18, 2016
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  4. MarkA

    MarkA In the doghouse. Supporting Member

    Sep 26, 2008
    Okay, it appears that if I embed single tracks, they'll work, but playlists won't. I've done this before successfully -- what gives? Anyone able to play the lists above?

    EDIT: Think I might have found a way. Working on it...

    EDIT 2: Tried something different. Seems to work. Should be four embedded playlists up, now. (I got rid of the 5th, that had all 21 files.)
    Last edited: Jun 18, 2016
  5. Matt Morgan

    Matt Morgan Fellow Conspirator Supporting Member

    Awesome comparison. I listened to every track and really appreciate the time and effort that you put into this.
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  6. Cowboy in Latvia

    Cowboy in Latvia

    Mar 1, 2015
    I'm subbing this thread and coming back later because I don't have my headphones or much time. Looks interesting and I'll try to reply in the next few days.
  7. TheRealKong


    Mar 17, 2011
    Same here. I appreciate the time and work you had with that comparison. As I only are able to listen by el-cheapo 2.1 - monitors I have to get my headphones and take some time to scrutinize all that stuff.

    I have the GBE 1200 and an old GBE 600 and have to say that they are able to give you nice overdriven tones when you drive the tube hard.

    Please, don't take this as an encitement to do more overdriven demos, as the Blue Rock and the Magellan are the only amps with dedicated "Drive" - section. ;)

    And, listening to my Bugera BVV 3000 and Ampeg V4b Ri with hard driven preamp, Genzler and Glockenklang did both a good job. :thumbsup:
  8. I listened to all of the tracks. Nice job! You had to listen pretty closely to hear the differences, which were mostly small. These all seem to be great amps. Occasionally one stood out and would have me thinking 'that's the one', but each seemed to have its moment. I guess that i like the blue Rock the most - there seemed to be a warmth to its tone that lent a degree of musicality that the others lacked or at least didn't have as much of. The GBE was a close second for me: articulate, dynamic and slightly warm. The Magellan and Kustom were both outstanding performers, and quite close to my top picks. I could be happy with any of them. It would be interesting to compare them to a couple popular 'workhorse' amplifiers like the GK MB800 and the Ampeg PF800.

    Thanks for posting!
  9. Thanks man, I'm totally stealing that chord riff for checking out overdrive circuits from now on!
  10. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    The tube channels on both the GBE-600 and 1200 are designed to be overdriven... not necessarily dedicated only for that but intended to get into that territory.
    TheRealKong likes this.
  11. TheRealKong


    Mar 17, 2011
    Yes they are. And they sound sweet when driven hard. I use them both with different degrees of saturation / overdrive, and I love it.

    But this is tube saturation. I wanted to say that Blue Rock and Magellan are amps with a "drive section" without tube, but as naturally, as identic to tube saturation as possible. A "dedicated drive section". OK, any "Drive Channel" should be able to give you more harmonics and some kind of "warm" sound when dialed in careful. Next step dirt, then grit, then overderive. At the end of the scale there is "facemelt", as I understand.....

    Maybe my first post agedhorse answered to was not easy to read, maybe somebody didn't get the meaning of what I wanted to say, but English is not my native language.
    So please be kind and forgive me. :whistle:
    agedhorse likes this.
  12. Type-55

    Type-55 Supporting Member

    Jul 20, 2000
    Great job.
  13. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    SW, OK
    You almost make me want to carry around a 50+ lb rack again!
    That GBE1200 is nice!
    The others are not too far behind (IMO) - close enough I don't think I'll go back to the 50+ lb rack.
    Thanks for the work you put in - great stuff!
    I wish you had a Mesa D800 & a Peavey MiniMega 1000...

    I bet you could use a looper to play the same set of licks over & over while you switched the amps around.
    murphy likes this.
  14. MarkA

    MarkA In the doghouse. Supporting Member

    Sep 26, 2008
    Hey, all. I'll pop in later and say some more, but wanted to take a moment to say thanks for the kind words. Thanks for listening.
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  15. murphy

    murphy Supporting Member

    May 5, 2004
    That was fun
    Glad I bought the Magellan
    Love my Mesa D-800 also.....that would be cool to add

    The blue Rock sounds beautiful.
    I resisted opinion on the big heavy amps...as I will never go back
  16. murphy

    murphy Supporting Member

    May 5, 2004
    oh and your preamp demo helped me decide to buy my Demeter VTBP201....very nice
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  17. MarkA

    MarkA In the doghouse. Supporting Member

    Sep 26, 2008
    Danke. Like many things, it took longer than I thought it would at first (even when allowing that it would probably take longer than I thought it would!). Anyway, it's done now!

    Sometimes, listening to the clips, they seem close to me, too, and sometimes I'm more attuned to the differences. Different things catch my attention at different times -- sometimes depth of tone and harmonic content, sometimes clarity and dynamics. I played around a bit with a looper yesterday (a little TC Ditto that I hadn't touched in months) and it's interesting to note how the different "voices" (say you have a layer each on the neck, both, and bridge pickups) are presented by different amps -- even with the same person playing the same instrument in the same take, the voices "sit in the mix" (their own mix) differently with different amps. Different amps bring out (or blend in) different things.

    The differences that I hear when listening to the recordings seem more apparent when playing, and more apparent yet when playing with a group. Some details can get washed-out in a live mix (especially a bad mix!), it's true, but some are brought very much to the forefront.

    Ha! Feel free.

    The looper thing -- I've listened to amps that way before (did a bit yesterday), and it can be useful. Didn't really consider using one when I made these clips. Pros and cons as I see them:

    • Each take is absolutely consistent.
    • Don't have to play the same thing 50 times (though that was good practice on that GM7 arpeggio!).
    • Lets me sit back and listen without worrying about playing -- sometimes you hear things, that way, that you might otherwise miss.
    • Puts one more piece (whether buffered or true bypass -- not sure how the Ditto behaves when looping) between the bass and the amp -- probably a minuscule effect with this group of amps, but, with my passive instrument, I want to see how it reacts with the front end of each amp.
    • Each amps responds a little differently -- a looper imposes the same touch on each amp (could be seen as a pro, too).
    • Listening without playing the amp in real-time removes much of the connection between your touch (though you still have the tactile memory of it) and what you're hearing from the amp -- sometimes you miss things, that way, that you might otherwise catch. A low F# that compresses a bit on playback might sound fine through the cab -- you might or might not catch that it's compressing -- whereas, while playing, that perceived spongy feel down there might clue you in to that much more quickly.
    I've never played the D800, though I did have a Minimega for about two weeks a couple of months ago. Mine had a bit of an issue, so I sent it back. That aside, I thought it was a neat amp with gobs of power. I had the Minimega and the Magellan at the same time. Those amps are an interesting case-in-point (re. con #2), actually. Each has a very different touch-response from the other. If you take the GBE as a point of reference, the Magellan feels looser and the Minimega feels stiffer. This is an oversimplification, as gain settings and other things can affect the feel of an amp -- and there's more to an amp's feel than "loose" or "tight" or "stiff" -- but it was a marked enough difference that it took me a few days before I was entirely comfortable playing the Minimega. Going between it and the Magellan, I altered my technique noticeably. If I'd recorded a loop so that it felt good with one amp (playing that one first), I'd almost certainly have played it a little differently than if I'd played it through the other. Which one, then, is the "right" take? I guess I could've recorded it while listening direct (no amp) and then played it through each amp, but that opens up other considerations.

    All that said, there's still a strong argument for the utility of a looper for clips like this (and your comment did help inspire me to mess around with mine). I think I'd have missed out on some of what I picked up playing all those arpeggios and listening back with the memory of playing them still reasonably fresh, but I might have picked up on some things more quickly, too.

    Well, you can still have an opinion. ;)

    I don't know if I'll always have a big, heavy amp. When I first got back into playing electric bass (just about seven years ago, now), I was not at all inclined toward beefy amps. I was looking at the magazines (and had just discovered the "amps" forum, here); 500 Watts in an amp the size of a hardback copy of Clan of the Cave Bear? 750 in an amp the size of a small VCR? Sign me up! It was obvious to me that the technology of my distant youth (the 90s, when I started playing the first time) had been surpassed.

    I owned a Shuttlemax 12.0 and a Markbass SD800 and was never entirely happy with the tone or entirely comfortable with the way they felt. I couldn't put my finger on why. At some point (after reading enough threads about it on TB), I said, "I'm going to find out for myself if there's really something to this whole lead sled thing those guys keep on about." (Battles over the topic raged at the time, with many casualties on both sides.)

    I picked up the GBE. (Not sure if I'd gotten rid of the SD800 by then or not -- I had a second one, later, and sold it.) Playing around at home, there were some notable differences in sound and feel between the GBE and the 'Max, but nothing earth-shattering. When I finally played the GBE out with a band, though, it took my breath away. So much more slam, so much more control and...

    So this is what it feels like. Suppressed, ancestral memories came flooding back -- amps I'd played and amps my prehistoric forebears had played before the mammoth hunts -- I could feel their power coursing through me... or perhaps it was something I ate. Either way, I liked the effect. Other players on stage and in the house noticed, too -- it wasn't just me.

    I won't argue over the inherent limitations of different amplifier topologies. I don't have the expertise. I do have a 10 year-old Lab Gruppen power amp (bought used, of course) that uses a switching power supply (they called their implementation of it "Class TD") and, even running one side (350 W @ 8 Ohms, 650 W @ 4 Ohms @ 1% THD), it's pretty slammin'. I imagine that they and others have made improvements since then. I will say, having owned the Shuttlemax, three different Markbass amps, a TH500, and a Demeter HBP-1 800D and played various Eden, Genz Benz, GK, EA, and assorted other small, switching bass amps, that there is a real and qualitative difference between the way they sound and (particularly) feel and the way the GBE does -- for me, in favor of the GBE -- and not only at higher volumes (though it is more pronounced there).

    I'm not saying that those are bad amps. I got enjoyment from all of them and all received positive comments when playing out with different people. I also know some serious and accomplished players who've used and use Shuttles and F500s and Acoustic Image amps to great effect on gigs. I used to slip my Markbass F500 into a gigbag pocket and played everything from little jams to an outdoor stage with it. I liked that amp. I like my little KXB 500 even more. But I also look at the ad copy and internet claims (which I willingly consumed and eagerly augmented with my imagination) surrounding amps of the last several years differently now.

    The new, light amps do, generally speaking, keep getting better. I don't want to discount that. The Magellan, in my opinion, is easier to use, sounds better, and feels better than my old 'Max 12.0 did. I've only had the Blue Rock for a little bit, but it's very promising -- clear, well-voiced, and solid (at least so far at home). Even the humble KXB, which uses an older power module (same one, I believe, as my 'Max did, though only one instead of two), is surprisingly punchy, articulate, and clear in a mix.

    I don't get to play out as often as I'd like to. When I do, more often than not, the GBE stays home. It doesn't make sense to take it out sometimes (or to some places) and, when you're getting home at 2:30 and getting up at 6:00, there is a certain appeal to an amp that you can throw -- along with all your cables, a book, a laptop, and some protein bars -- into your backpack. There have been times, though, when it's been totally worth it to bring the GBE (I've never regretted it while playing) and a handful of times when a 500 Watt micro just would not have done the job.

    A big part of what the GBE provides for me right now, while I indulge myself and try out all this other stuff, is a known-solid reference point. Forget about class AB or class D. EDIT: Okay, I can't totally forget about it, but I'm trying to evaluate amps based on how they perform, without either dismissing one out of hand or cutting it slack based on its topology. The GBE happens to be my "reference rig" for this.

    Cool! How do you like it?
    Last edited: Jun 23, 2016
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  18. MarkA

    MarkA In the doghouse. Supporting Member

    Sep 26, 2008
    The tube channel on the GBE will indeed yield a significant degree of overdrive -- nothing too crazy, just running on the neck pickup of my passive bass, but if I throw the neck and bridge in series (I have that wired on a push/pull pot) and dig in, it'll get get raunchy. I haven't run it that way in awhile, though. It occurred to me, after I'd recorded everything and packed up, that I could, but I was pretty clipped-out by then. When I read your posts afterward, I thought about doing one, just because, but I'd already moved the mic and the OD potential of the GBE hadn't occurred to me as a feature to highlight, though perhaps it should have.
  19. murphy

    murphy Supporting Member

    May 5, 2004
    Well MarkA....I am thrilled with my Demeter VTBP201....fat, thick, clear and warm....and sounds incredible running into the poweramp of my Magellan.....I am once again thrilled with my amp. and also enjoy the Magellan....but prefer the Demeter a bit more.
    I am also using my Mesa D-800 in various situations....it is different....but always satisfies my needs

    I feel so fortunate to have two great new amps and an older preamp that can be used in my rig also.....Good times indeed
  20. shrigg

    shrigg Joy Decision Bassist/BL, AudioKinesis Beta Tester Supporting Member

    Sep 7, 2007
    Traverse City, MI
    What an excellent analysis of all these amplifiers and their subtleties. Thanks for doing this @MarkA. Your substantial effort is appreciated and this thread will become a reference to anyone considering these amps. Enjoyed it very much along with the discussion, thank you!

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