ohm buttons

Discussion in 'Amps and Cabs [BG]' started by davetsbass, Apr 11, 2001.

  1. davetsbass

    davetsbass Guest

    Mar 24, 2001
    burnt hills NY
    I was curious if there are any amps where your can switch the ohms from 8 to 4, I dont belive that to be possible but oh well.
  2. rickbass

    rickbass Supporting Member

    A Marshall I used way back had one. Don't know if the latest models have `em and don't remember if it was 4 to 8, vice versa, or even 16.
  3. Christopher


    Apr 28, 2000
    New York, NY
    Tube amps are usually equipped with this kind of switch, since (I think) impedances have to be stepped up from the preamp for the tube stage and then stepped down again for the speakers.

    Solid states don't need this as pre- and power- stages are already impedance-matched; most can run at either 8 or 4 ohms without difficulty.
  4. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    Tube amps have an output transformer. The switch just taps the output transformer coil (don't know the english technical term) at different places to match different speaker loads.
    Solid State amps don't need an output transformer.