Ampeg V4BH as preamp only

Discussion in 'Amps and Cabs [BG]' started by rumblefish, Feb 23, 2006.

  1. I like the tone of my amp, but I have the usual complaint of not enough volume at hard-rock level gigs. So I've taken to using my QSC RMX 1450 to amplify the balanced line out of my amp, and the results are great.
    My question: Will running the Ampeg with no speaker load do any damage? Would a power brake be called for here? I wonder if I should yank out the power tubes and use the head strictly as a preamp.
    Any thoughts on this all you Ampeg fanatics?
  2. Passinwind

    Passinwind I Know Nothing Supporting Member

    Does the amp have a power amp input? In many cases that input cuts signal to the power stage. I've successfully used a 1/4" shorting jack plugged in there as a simple cutoff mechanism on quite a few tube amps. I've never even seen a V4BH though, so check into this carefully before you try it please. The power amp input on the last old V4B I worked on was not the type that cuts signal, FWIW. But then, it's called External Amp Out on those amps, so...

    Just pulling the power tubes intuitively seems like a winner, but it's often not a great idea. The power supply in some amps can get dangerously close to over spec with respect to the filter caps once that load is gone. Plate voltages to the remaining tubes will go up too. Sometimes it's fine, but not always. I'd suggest you ping Jerrold Tiers and get it straight from Ampeg.
  3. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    Another option would be to pick up a small cabinet on the cheap that you could use as a load/monitor. Maybe you could mic that one instead of the RMX powered cabinet, so you get some tube power amp sound in the house PA.