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Can I run a 4 ohm cab + an 8 ohm cab with an SVT Classic Head?

Discussion in 'Amps and Cabs [BG]' started by AndyMan, Apr 29, 2006.


  1. AndyMan

    AndyMan Supporting Member Commercial User

    Jun 17, 2000
    Columbus, Ohio
    http://myplaceproductionsllc.com/
    Hey guys--

    Need some advice:

    I've got an Ampeg SVT AV head (Actutally it's a classic w/ diff cosmetics). It's 300 tube watts @ [edit 4 or 2 ] ohms. I have 1 SVT 410 HE cab wired @ 4 ohms, and a 2d 410 HE wired @ 8 ohms.

    Can I hook up both w/o dmaging the head?? If so, how would I hook them up?

    Thanks,

    Andy
     
  2. AxtoOx

    AxtoOx

    Nov 12, 2005
    Duncan, Okla.
    Though not recomended, tube amps don't have the same problem w/ frying the chips the SS and Hybrid do. If I remember correctly, it will handle a 2 ohm load though they don't say it. You should be able to run them in parallel or series either one. You'd be better off in series.
    Are you sure that Ampeg is not 8 ohm? I've never heard of an HE in 4 ohm. That just means I've never heard of it.
     
  3. AndyMan

    AndyMan Supporting Member Commercial User

    Jun 17, 2000
    Columbus, Ohio
    http://myplaceproductionsllc.com/
    Hey AxtoOX--

    I bought a a 410HE re-wired in 4 ohms.
     
  4. I may be wrong here, but arent the AV and CL heads 2 and 4 ohm?

    I could be wrong, im just going my SVT which has 2ohm and 4ohm switch

    - Will
     
  5. I just looked on the ampeg site, says its 2ohm or 4ohm, not 8ohm or 4ohm for the CL/AV

    - Will
     
  6. AndyMan

    AndyMan Supporting Member Commercial User

    Jun 17, 2000
    Columbus, Ohio
    http://myplaceproductionsllc.com/
    You are correct.
     
  7. Can you not rewire your 4ohm cab to 8ohms? then run the two in parallel then you've got a 4 ohm load
     
  8. AndyMan

    AndyMan Supporting Member Commercial User

    Jun 17, 2000
    Columbus, Ohio
    http://myplaceproductionsllc.com/
    well--

    my idea is to use the 4 ohm 410 for smaller gigs, and 2 410s for larger. That way, I can get 300 watts with either setup.
     
  9. Erm, when using a 300 watt tube head you will get 300 watts at both impedances, so if your using a single 4 ohm cab you will get 300 watts, if you are using two 4ohm cabs (giving a 2ohm load) you will get 300 watts, tube amps dont work the same as SS amps in that respect

    - Will
     
  10. AndyMan

    AndyMan Supporting Member Commercial User

    Jun 17, 2000
    Columbus, Ohio
    http://myplaceproductionsllc.com/
    right--and 2 410s = easier to transport than 1 810.
     
  11. Dont know what that has to do with it but thats debatable :p

    With the two 410's at least you have the option of taking half your setup to a gig :)
     
  12. Sorry for slight hijack, but what is the load of an 8 ohm and 4 ohm cab running together? Somewhere around 3 ohms?
     
  13. AndyMan

    AndyMan Supporting Member Commercial User

    Jun 17, 2000
    Columbus, Ohio
    http://myplaceproductionsllc.com/
    2.67, I believe
     
  14. What's the formula?
     
  15. 1/I = 1/4 + 1/8

    1/I = 0.25 + 0.125

    1/I = 0.375

    I = 1/0.375

    I = 2.666667

    If i remember correctly?

    Something along those lines anyways, im a biochemist i havent done much physics/electronics in the last 4 years :p
     
  16. Dragonlord

    Dragonlord Rocks Around The Glocks

    Aug 30, 2000
    Greece, Europe
    Yep. It's easier this way:
    1/I = 1/4 + 1/8
    1/I = 2/8 + 1/8
    1/I = 3/8
    I = 8/3 = 6/3 + 2/3 = 2 + 0.67
    ;)
     
  17. Dan1099

    Dan1099 Dumbing My Process Down

    Aug 7, 2004
    Michigan
    I'm curious how a cab that is normally 8 ohms can be rewired to 4 ohms. I don't think that's doable, man. Anyway, there's no point in having it at 4 ohms with a tube head, so I'd return it to stock wiring if I were you.
     
  18. oldrocker

    oldrocker

    Feb 13, 2005
    Long Island, NY
    OR

    (8 x 4) / (8 + 4) = 32 / 12 = 2 8/12 = 2 2/3 = 2.67

    :bag:
     
  19. AndyMan

    AndyMan Supporting Member Commercial User

    Jun 17, 2000
    Columbus, Ohio
    http://myplaceproductionsllc.com/
    My SVT must be run at 4 or 2 ohms.
     

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