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Not just another cab mixing thread; we're talking mixing amps...

Discussion in 'Amps and Cabs [BG]' started by Michedelic, Apr 23, 2015.


  1. Michedelic

    Michedelic MId-Century Modern

    OK, everybody calm down...this is merely a theoretical inquiry about using different amps into individual but identical speaker cabinets. First off, yes, I used the search function. Maybe I didn't word it properly, but I came up with nothing. If you know of a similar thread in the past, I'm sorry. Secondly, please refrain with any "why would you want to do that?" comments, as in "why would you want to use 15's instead of 10's", or "why would you want to drag all that iron around when you can just slip a class D Uberbomb 1000 into your gigbag?" I just do. Also, let's just assume that there's a 'not too bright but can lift heavy things' neighbor kid I can slip a 20 to to help me move stuff. AND, once again, this is just a theoretical discussion. I'm just trying to gain knowledge. So....
    For simplicity's sake, I would have four identical textbook 1x15" TL cabs, each loaded with a 200 watt EVM 15-L. Laid on their sides, and stacked vertically(ports all on one side), there shouldn't be any speaker phase issues, correct? The four amps to be used would be: 1974 Marshall Super Bass(4x6550), Sunn Model-T, 1st generation(4x6550), Sound City 150B(4x6550), and Fender Studio Bass(chopped into head format, 6x6L6). Two heads each in two 'live-in' road cases. Which head to which cab in the stack will be determined later. A Voodoo Labs Amp selector switcher would be employed. Now, yes, I'm aware that there have been certain GUITAR amps with input and output phase quirks(the Vox AC30 has a channel whose inputs are out of phase with the other two, and I believe the Fender Super Reverb output is reverse phased; if I'm wrong, and if there are any other amps out there like that, please inform me). Now, assuming that the phase on all of my four amps(I actually do own all four of those)are proper, would there be any phase(or any other performance) issues from all this accumulated equipment(aside from potential power supply ground loops or potential shock problems)? Would the variety of tone stacks in play create any problems? That's kind of the reason for attempting this experiment, to 'layer' the different sounds of the various amps. Thanks in advance for any observations/knowledge.
     
    metalinthenight likes this.
  2. iualum

    iualum

    Apr 9, 2004
    60453
    Very best of luck ;) .
     
    lomo and Munjibunga like this.
  3. RickenBoogie

    RickenBoogie

    Jul 22, 2007
    Dallas, TX
    So I assume, each amp connected to it's own cab at all times(?) I would think two amps, each connected to a pair of the cabs would sound "bigger", but so long as everything's happy impedance-wise, and phase-wise, .........
     
  4. If I were to do this, the top amp would be some little easily over driven guitar amp with a high pass filter.
     
    bassie12 likes this.
  5. Gaolee

    Gaolee Official leathers tester and crash dummy

    I think you are crazy in the best possible way. It is great! Aside from the phasing issues, which could be solved by swapping the leads in the offending cabinet at the jack, I don't know why it wouldn't work. Ric-o-Sound lets you do something like this on a smaller scale. What you are thinking about doing would be Michedelic-o-Sound.
     
  6. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Sounds like you've thought through things well. You can get devices that will switch cabs on a single amp. The opposite to what you are doing.

    Perhaps you will want a buffer that will send your instrument signal to all four amps.

    Different tone stacks will give you more tonal flexibility.

    Balancing the volume levels may take some doing. The amps will have different frequency responses. Levels that are even at the bottom may not be at the top. Not a big deal though.

    You won't know if you'll like it till you try it. You will love the wall of sound.
     
  7. cfsporn

    cfsporn

    Aug 20, 2011
    New York City
    I'm not too sure of the science regarding mixing amps, but I am sure that my back started hurting when I read that you were planning on bringing four big tube heads to a gig.

    I mean this with love, respect, and admiration; you are certifiably crazy. :D:laugh::smug:
    :p
     
  8. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    amp switcher? screw that, run 'em all at the same time, all the time! +1 to using a buffer of some sort before any input signal splitting so the full bass signal gets to all 4 amp inputs.

    i don't see why it wouldn't be cool, or why the cabs wouldn't play reasonably nice together even if the amps had slightly different EQ curves or distortion levels (as long as you got the polarities right like you said).

    also, i'm now totally in the market for a class D Uberbomb 1000 to slip in my gig bag :hyper:
     
    friendlybass likes this.
  9. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Each amp will have different phase and group delay characteristics depending on EQ settings and a variety of other things, regardless of simple polarity issues. To me that would be the whole point of the exercise though -- why settle for mud when you can have quicksand? I would definitely not mess with hot-switching high power tube amps under any circumstances, personally.

    The Uberbomb 2000 blows away the UB1000, BTW. [​IMG]
     
    friendlybass and Coolhandjjl like this.
  10. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    I don't know.
     
  11. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    i assume by that you mean any kind of cab switching, that is, between the heads and the cabs; i'll be damned if i let that happen to my vintage marshall either!

    switching of inputs between multiple amps, all safely on their own cabs, is of course no big deal.
     
    friendlybass likes this.
  12. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Yep, but if I carried all that stuff in I'd danged sure run all of it all night.
     
  13. agedhorse

    agedhorse SUSPENDED Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    I think Charlie has it right. There is polarity, and there is phase (they are not the same). Each amp will have its own phase response, and when you combine the acoustic signals from speakers fed by amps with different phase responses, the results will vary and may be ok but also may be terrible. There's no way to predict without trying.

    I too wouldn't recommend switching high power tube amps at high volume.
     
    Coolhandjjl likes this.
  14. Fuzzonaut

    Fuzzonaut

    Aug 27, 2013
    Switzerland
    I think that should work just fine.
    And I like your style ... and your amp collection.
     
    friendlybass likes this.
  15. strictlybass_ic

    strictlybass_ic Mediocrity is a journey

    Jan 9, 2014
    Northern Indiana
    Phasing issues due to array alignment: sounds like you should be okay
    Phasing issues due to different amps responding to the varying impedance and feedback from the drivers: I want to meet the guy who can figure that out mathematically (likely to vary widely between fine and not so fine)

    The bit of advice I share on the multi-amp threads (and this is from experience) is that sound check can be a real pain, especially if you have pedals in the mix somewhere. Just remember that each amp (and each channel on each amp) is a separate gain structure, and to first balance and then sound check each different gain structure can become a time consuming annoyance. Not saying it can't be done, but keep that in mind when you're planning how early to arrive at the gig. Also, the more complexity you add to a rig the more opportunity for error there is. For something like this I'd keep a handful of extra cables and maybe a spare switching box. It's also a good idea to practice tear down and setup a few times before trying it out at a gig so you're not troubleshooting on stage instead of doing your lengthy soundcheck.

    That said, this sounds like it could be a lot of fun to play through. Here's hoping it works out how you want and nobody slips a disc getting it all in place.
     
  16. If you don't mind the moving and setup, it can work.
    With a little practice you can find which amps and combinatins
    will give you what sounds.
    I don't think you will really need all of them at once,
    but different pairings could give some interesting results.
    If you don't already have the 4 TL606s, I would suggest
    building with 3015s instead of the EVs.
    EVs are still fine speakers, but they weigh a ton and don't go as low.
     
  17. Can't answer your question, but I sure am looking forward to the pics of that rig!
    Fishheadjoe
     
  18. Coolhandjjl

    Coolhandjjl Supporting Member

    Oct 13, 2010
    Appleton
    Why?

    Find the head that produces the tone you like, and connect via slave amp style with more of the same head if you think you need mega-juice.
     
  19. groovaholic

    groovaholic The louder the better. Supporting Member

    Sep 19, 2004
    Grand Rapids, MI
    Here's a suggestion: get 4 different colors of electrical tape and put a square of it next to the amp output jack and a square of it next to the corresponding speaker input jack. Then wrap a length of that same-colored tape around each plug on the ends of the speaker cable for that connection.

    Having all of those connections color-coded will make setup and troubleshooting SO much easier...
     
  20. Radial may help in this endeavour.

    headbone-vt-top. There are also Tube/Solid State and SS/SS switchers

    jd7-stack-front. Up to 7 amps at the same time, fx...

    jx44-panels. Up to 6 amps, wireless, fx...
     

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