Why do Guitar heads lack ground lift and direct out?

Discussion in 'Amps and Cabs [BG]' started by DiabolusInMusic, Apr 18, 2012.

  1. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism

    I realize this is a bass forum but I don't post on guitar forums, so this will be the most likely place for my answer. Anyways...

    At the jam last night, singer/guitarist kept getting a shock through his mic, long story short it was his power cable, gave him mine and finished the night fine. I wasn't singing last night, but if I wanted to hook up a mic I thought I'd have been fine by lifting my ground. (Is that correct? I don't know, hoping for some info there.) There was no ground lift on his head, Hughes & Kettener Switchblade 100, and other guitarist said his Mesa Boogie also lacked one. So why no ground lift on guitar heads?

    I also noticed there was no direct out on his head, there wasn't one on my old Marshall either, every bass amp I own, including any of the larger combos have all had a direct out. Why is that? Is it just because of tone? I have hit the road with a guitarist who used a line6 modelling pedal for an amp, just direct into the mix with good monitors. I have seen many bassists do this, thought about doing it myself, never seen any other guitarist do it. Rarely would he even get asked where his amp was, the tone was fine.
  2. Dave W

    Dave W

    Mar 1, 2007
    Westchester, NY
    A lot of guitar amps do have ground lifts, just like not all bass amps have them.

    As for the DI, I suspect it's still relatively new and not a lot of guys have embraced it. There are plenty of modelers out there that do have a built in DI, just not everybody likes modelers.
  3. BassmanPaul

    BassmanPaul Inactive

    The ground lift is for removing a possible ground loop caused by using the DI. If no DI the ground lift is not required.

    Typically if a guitar player is to go through the PA he will demand a microphone. His speakers are as much a part of his "sound" as the amp and instrument. I feel that mine are too and I really dislike my tone direct through the PA.
  4. will33


    May 22, 2006
    A lot of guitar tone is derived from speaker voicing, breakup, etc., even their clean tone....a mic is needed to capture that.

    The shock thing was likely because the ground pron was broke on his power cable or something. I've had that happen before only to unplug the mixer and find the ground prong stuck in the outlet. He probably just needs a replacement end or new cable.
  5. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Guitarists are always mic'ed. It's always assumed that a guitarist is going to want a mic. They are treated well. Just the opposite with bassists, where DI is king, and if you pull out a cab mic, soundmen look at you like you just pulled out a human head, then try to force you to plug into a $50 DI to suck out all the balls of your rig.
  6. laylawguw

    laylawguw Guest

    Apr 18, 2012
    That's what i think too [​IMG]
  7. coyote1


    Mar 23, 2012
    The issue is mics in a live setting. Properly capturing those low frequencies ain't the easiest thing in the world. Far easier to take a line out, especially if the PA has good subwoofers. If your amp is equipped with a direct out, you get to send a copy of what's hitting your own speakers to the PA speakers. For a bassist, it's a good arrangement. The direct box? Fugheddaboutit.
  8. BassmanPaul

    BassmanPaul Inactive

    I disagree. The DI could be pre EQ or post. Could also be pre FX or post. the DI eliminates any contribution the the speaker system gives your tone.

    Edit: It also eliminates what the power tubes give you in the case of a tube amp.
  9. Given the much shorter wavelength frequencies that guitars produce, it's easier to capture more of the wavelength with close mic'ing to a guitar cab than it is with a bass cab, because obviously the bass produces much longer waves. Another reason why bass speakers don't usually sound very good when you're extremely close to them...
  10. teemuk


    Mar 1, 2011
    Maybe because...

    The ground lift is just a switch that disconnects the ground reference from the secondary side of an isolating audio transformer in the DI circuit. A procedure that can cure nasty ground loop induced hum. So... No DI circuit, no ground lift.

    And no, a ground lift switch would have not cured the issue of mic shocking the singer because his amp had a poor ground due to broken power coord. Entirely different issue. In fact, it was an issue of the broken power coord "lifting" the chassis ground, which as a standard safety measurement should pretty much remain grounded constantly. You most certainly DO NOT want to "lift" the chassis ground, that can be fatal.

    It's a useful feature.

    There are several guitar amps that will also have one but you could also wonder why most guitar amps have no graphic EQ, built-in compression or plenty of other useful features typically found from bass amps but not as typically from guitar amps. Maybe it's a preference thing; guitarists tend to be somewhat conservative bunch and still like to go with miking speaker cabs, experimenting with different cabs, speakers and miking configurations, using dummy loads, power soaks and all - instead of just using a DI output, which sounds way different than blasting an overdriven power amp through the speaker cab, and then miking up the mess - even if you throw in some cab sims.

    So, maybe the larger portion of the market is simply too conservative to appreciate a feature such as DI enough that manufacturers don't see a reason to fit one in as a "standard feature".
  11. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Or maybe it just sucks for guitar ;) Sorry, never ever heard a DI line for guitar that sounded as good as an amp being mic'ed. I hear dudes use them all the time and it always sounds thin and blah. Maybe if they had better DI's on them like my REDDI, or if they had speaker out DI's on the tube amps, but they don't.
  12. jaywa


    May 5, 2008
    Iowa City, IA
    Don't know on the ground lift question.

    Re the DI... most times I've heard a guitarist run line-out to the board as opposed to micing the cab it sounds terrible. Mic'ing the speaker is still the overwhelming method of choice for running guitar through P.A.
  13. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism

    Pretty much what I thought it was.

    Thanks all, my questions have been answered.
  14. walterw

    walterw Supportive Fender Commercial User

    Feb 20, 2009
    hee hee :D

    "no no, just plug into his left eye socket here..."

    electric guitar is a"lo-fi" instrument, and the significant frequency-narrowing and coloration of the speaker is critical to its sound; the only DI options worth a damn are those that simulate the sound of the miked speaker anyway.
  15. Joe Louvar

    Joe Louvar Guest

    Jun 6, 2011
    Santa Rosa, CA USA
    Because there are already to many guitarist in the world, so no gnd = one less ~ NOTE: I'm Just Joking!!! :D

    EDIT: besides, don't guitarist just cut the gnd pin off their pwr amp cords anyway, lol. :D
  16. billfitzmaurice

    billfitzmaurice Guest Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    That's the myth of wave propagation you're repeating there, and like all myths it's not true.
  17. walterw

    walterw Supportive Fender Commercial User

    Feb 20, 2009
    yep, i can hear those 5-10' waves with my IEMs (in the sealed-up inch or so of my ear canals) just fine.
  18. LiquidMidnight


    Dec 25, 2000
    My guitarist has an excellent DI on his SansAmp PSA-1*. When we work with a new sound engineer, my guitarist always gets the same response when he tells the engineer he can use the DI. First, the engineer's real skeptical. Then after the first set, the sound person runs up to the stage and gushes about how great the DI sounds. For the most part, though, my guitarist runs both a DI and a mic.

    I wish sound engineers were as excited to mic my cabinet as they are to mic my guitarist's cabs. We had an engineer this past weekend that seemed scared of my head's onboard DI and wanted to use his box before my amp. Not suprisingly, most engineers I know who are very apt to mic a bass cab are bass players themselves.

    *Of course, it's a SansAmp, so I imagine it already has some sort of speaker emulation built into it.
  19. will33


    May 22, 2006
    You've heard one?

    IME/O, whatever, guitars don't use DI for good reason, it's always a mic.......always. I can see the controlling of deep lows a benefit with a hard wire, but I wish we would see more bass mic's. That said, when running our own little band through full PA, I always take a post eq/post "amp flavor" DI. Much easier, sounds good. Guitars get a 57, period.
  20. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    I'm afraid I have heard them several times. I've used them on recordings I've done my own self because I can't be blasting guitars here at 1 am with a baby in the house. Never as good as a mic.