A few questions about Ampeg V-4BH

Discussion in 'Amps and Cabs [BG]' started by jenderfazz, May 8, 2005.

  1. 1. The presence switch behind the head seems to make it a lot brighter. Can anyone give me exact details on what is boosted?

    2. The ultra-low button is supposed to boost lows and basically suck the mids out right? What about the ultra-high button?

    3. The -15db input lowers my output by 15 db right? My bass is too overdriven, so I plug into it. Of course, that means a cut in volume. Say I were to boost my volume to meet the original level... would I have the same overdrive? What if I boosted each band accordingly? Can someone give me some details on it?

    Thanks a lot in advance.
  2. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Frequencies are boosted above about 1500 Hz or so. The Presence control works in the power amp, however, which gives a little different response than a tone control in preamp.

    Correct on Ultra-low. Ultra High is similar to the Presence control, but is in the preamp.

    The -15dB input lowers the level BEFORE it hits the first tube. There isn't any volume control until after that tube, so any overdrive in the first tube can't be corrected or controlled by adjusting any amp control. It is "uncontrolled" distortion, and you have to use the output control on the bass to fix it, or just use the -15dB pad.

    Active basses typically have higher signal outputs, so it can come in handy to beable to cut that.

    Obviously, if you reduce by 15 dB at the input, max gain is reduced 15 dB. So ultimately, no you can't get as much with that in. But you can probably get "enough".

    If you use the output level on the bass to cut just enough to avoid uncontrolled distortion, you may not need to use the pad. But you might need to remember not to roll that control to full. The pad can be handier.
  3. Thanks a lot Jerrold, had a feeling you would clear things up.