Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Safe to run a hybrid amp head with no cab attached?

Discussion in 'Amps and Cabs [BG]' started by Fender32, Sep 29, 2005.


  1. Fender32

    Fender32

    Jun 23, 2005
    Kent, England
    Sorry, more "Newbie" questions for y'all.

    I've just accquired my first ever amp without a headphone jack (Ampeg SVT Pro4) and I'd like to test it out at home. The problem is, I don't keep my cab in my apartment to plug it in to. Longer term, I'd like to be able to record through it at home too (i.e. without a speaker attached).

    So, the question is:

    :help: Is it safe to power up the amp without a cab attached and just run the pre-amp output into a mixing desk? If it is ok to do this, are there any tips on how to adjust the various levels (i.e. gain, master and line out level) for optimum sound, or can I just experiment without of fear the amp melting?

    Thanks in advance for your comments. :)
     
  2. aslong as there isnt a tube power section then yeah its ok
     
  3. Fender32

    Fender32

    Jun 23, 2005
    Kent, England
    Yeah, the power stage consists of two transformers, only the preamp is tube powered.

    Is that the issue then, overheating the power tubes? I'd kind of heard that it was something you shouldn't do, but I never knew why.

    Is it ok to run the preamp with a lot of gain on then (I guess the fans will cut in if necessary)?

    Sorry about the dumb-ass nature of these questions, you'd hope that someone would know the answers to these sort of things before being let loose with such a top bit of kit, wouldn't you? :rolleyes:
     
  4. I know, i was just saying its only amps with a tube power stage that need a "load" , erm, its not to do with the tubes themselves, i think it to do with the output transformer . . . not 100% sure

    (btw, i think you mean your power stage has two transistors? )
     
  5. permagrin

    permagrin

    May 1, 2003
    San Pedro, CA
    I'd say yes, but RTFM applies as well....
     
  6. Fender32

    Fender32

    Jun 23, 2005
    Kent, England
    If that (RTFM) means what I think it means, the FANTASTIC MANUAL doesn't even cover the subject. It only has diagrams of how to wire it up to varying numbers of cabs, for playing either Shea Stadium, or more modest venues such as Madison Square Gardens. I guess it's not an amp meant for people who don't own or have full-time access to a recording studio.

    Any other views will be much appreciated.
     

  7. The SVT-4Pro is not transformer-coupled so there's no problem running without a load. No problem at all. It's a safe bet that you can do this with just about any modern solid-state amp.
     
  8. Tash

    Tash

    Feb 13, 2005
    Bel Air Maryland
    The SVT-4 Pro has a direct out, I suggest you use that, not the cabinet outs.

    Sending a few hundred watts to your mixing deck is probably bad for it.
     
  9. Fender32

    Fender32

    Jun 23, 2005
    Kent, England
    That'll be one of the two (A & B) the Preamp outputs, yes?

    Thanks a lot for your help guys. :)
     
  10. Tash

    Tash

    Feb 13, 2005
    Bel Air Maryland
    I belive there is an XLR direct out with level control as well. Use that or one/both of the preamp outs.
     
  11. Fender32

    Fender32

    Jun 23, 2005
    Kent, England
    Hey, your not wrong! I'll try using that instead (I wasn't sure about it before, because the manual said something about it being a "balanced transformer output", which made me think it might involve the power stage).

    Anyway, I'm off to blow myself up! :hyper:

    Thanks again for all of your :help: .

    :D