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80's ampeg svt head and ampeg 8x10 squareback concerns...

Discussion in 'Amps and Cabs [BG]' started by DrowningBrian, Aug 25, 2012.


  1. DrowningBrian

    DrowningBrian

    May 21, 2009
    Atlanta, GA
    im very proud to have this rig, its beastly.
    i have an 84(i think) ampeg svt head its japanesse made.
    when i turn the bass knob past 12 noon it seems to be too much for the cab. is this normal for these squareback cabs?
    or do i have a speaker issue?
    it never farts out though.

    the peaks seem to be too much too with hard attack, maybe i just need a compressor, i dont know. looking at the maxon cp-9 pro+
    should i put 1 GE 5751 in the V1 preamp slot and 1 in the phase inverter slot? to maybe tame the beast and maybe drive the power section harder.
    i played a 73 ampeg svt and it sounded better/smoother/focused it must be the preamp with the 12dw7's in it. maybe i should just trade somebody. lol
     
  2. will33

    will33

    May 22, 2006
    austin,tx
    The old squareback cabs used drivers that were a little more guitar-ish oriented, not the higher power ones of today. You probably just found the cabs limits as far as low frequency handling. The original SVT rigs back them were sold with two 810 cabs. It is possible for the amp to overpower one of them. Gets damn loud by the time you get that far though.
     
  3. DrowningBrian

    DrowningBrian

    May 21, 2009
    Atlanta, GA
    that sucks. wow else nobody can give any feedback. weird.
    will33 what year did they up the power to 400 watts? what were the good years of that rating?
     
  4. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I want to be Tesla (tinkerer at Dayton Amp Co)
    They used CTS speakers from '69 to '74 in the squarebacks and later switched suppliers. Those speakers have a certain magic that the rest don't. Just IMO. :smug:

    Still, sounds like you're pushing the cab too far. The original SVT's without a doubt did need two of those 810 cabs to really open up. Sounds like yours might too. ;)

    Then again, there are plenty of smaller modern cabs that can take anything that SVT can throw and more and do so with considerable volume. My personal favorite SVT match-up was with Genz Benz and Bag End cabs.
     
  5. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    You need to get an 810 from the mid-90's on if you want 800w power handling, and an early 90's cab if you want 400w...I recommend the 800w handling cabs for you. Love the sound of my old squareback, but wouldn't dream of cranking an SVT through it. And the newer ones from 2007 till now are the best built and sounding of the higher power handling 810's. Lot of info on those cabs on here, but that's the short version.

    Nice score, though...absolutely wonderful sounding rig if you can live with the power handling restriction.
     
  6. will33

    will33

    May 22, 2006
    austin,tx
    +1 to the squarebacks, man. Forget about uber low frequency power handling and all that stuff that we agonize over now and just listen to tone. The squarebacks have a "mojo" that you just don't get now. Despite everything going "lower, louder, better", etc. You got a prize winner there.
     
  7. I had the same problem. Sold the CTS speakers and replaced them with Legend B810s. Almost the same tone but a little more low end and a lot more power handling.
     
  8. anderbass

    anderbass

    Dec 20, 2005
    Phoenix. Az.
    Yeah but where's your amps volume knob set to when this happens?

    Does the cab have this issue even at lower volume levels, or only when when the amps volume knob is set above 10:30? Or where?

    Are you boosting lows on an active bass by any chance too?
    (are you playing a 5 or 6 string, and only have this problem on low-B notes?)
     
  9. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Ampeg originally intended that the SVT was supposed to used with two of the square back cabinets. At moderate levels, one works fine and the tone is fantastic. But as others have said, if you want to crank it, those old lower wattage speakers are not going to stand up as well as those in the newer cabinets. You are at risk of damaging them.
     
  10. DrowningBrian

    DrowningBrian

    May 21, 2009
    Atlanta, GA
    thanks guys! good info here.
     
  11. DrowningBrian

    DrowningBrian

    May 21, 2009
    Atlanta, GA
    usually i have volume around 9-10 oclock anything over this it feels like my head might explode and i cant hear the drummer or guitarist. it definately starts to sound awesome the more you crank it. i play a p bass in alot of different tunings.
     
  12. DrowningBrian

    DrowningBrian

    May 21, 2009
    Atlanta, GA
    oh yeah man the tone is amazing! i had a slm 8x10 and it was just dark and boring. the squarebacks have THE tone. and it actually like 25 pounds lighter than modern 8x10s. to be honest i really dont ever need the bass knob over 12 noon, i was just wondering if this was normal. i wish i could have 2 squarebacks but i couldnt imagine hauling both to shows. lol
     
  13. hd5054

    hd5054

    Jul 20, 2012
    Union sc
    If u have the square back cabinet it's only 240 watts. They done that so that u could run 2 cabinets an have enough power to push them but not enough to over power them. U will have to either get another cab like it or find a newer one. Also the Japan svt have a harsher sound cause of the different preamp tubes an different transformers. The next up cab was rated at 350 watts an then they went on up in power handling. I hope this helps u
     
  14. DrowningBrian

    DrowningBrian

    May 21, 2009
    Atlanta, GA
    thanks man. yeah mine does seems a little more harsher than the 70's svt head that i played, still sounds great. im gonna try and keep the cab. if i start blowing drivers than i'll look into something else.
     
  15. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Sorry, but I don't find the Japanese heads to be harsh at all. To me they sound like all the other ones.
     
  16. DrowningBrian

    DrowningBrian

    May 21, 2009
    Atlanta, GA
    thats weird maybe it was biased hotter or something. you know your ampegs so i believe you.

    nobody answered my tube question. can you jimmy?
     
  17. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    I have no experience using 5751's, but I don't see what there is to gain out of using a non-spec tube.
     

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