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18V Active Electronics

Discussion in 'Pickups & Electronics [BG]' started by Rafterman, Apr 14, 2001.

  1. when it says "18V active electronics," does that mean that it uses 2 9V batteries, or what?...does a BTB-405 electronics run on 18V?...i know THIS is a GOOD BASS.
  2. Nino Valenti

    Nino Valenti Supporting Member Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
    Yes, if it says 18V it's 2 9V batteries. As for the BTB 405, I believe it has a 9V pre-amp, but I'm not 100% sure.
  3. Steve Lawson

    Steve Lawson Solo Bass Exploration! Supporting Member

    Apr 21, 2000
    Birmingham, UK
    FWIW, a lot of 9 volt circuits can be rewired for 18v, just by adding another battery. It doesn't increase the volume significantly, but it does increase the headroom, so you can play harder without the sound squashing - it 'opens up' slap playing and chordal strummy stuff....

  4. Hi Rafterman.

    Have a squint at my thread, "Why bother with actives on a bass". One or two of us chew-over the 18 Volt business.

    If you want to go from 9 to 18 have an electronics man look over the actives first. There could well be more to it than just adding batteries: like 'smoking' the circuit. Beware.

    Best wishes.

    Rockin John
  5. Angus

    Angus Supporting Member

    Apr 16, 2000
    Palo Alto, CA
    18V = 2 (9V). How often do YOU see 18V batteries? ;)

    Yeah, the BTB is 18V. Not all preamps can be rewired for more headroom, usually because of the wires used (i believe). However, some can be wired up to 36V! :eek::eek::eek:
  6. Generalisations are dangerous, I accept that. However, actives with 2 batteries (18 Volts) will probably use the common connection point of the 2 batts as the zero Volts, ground. That is likely to be connected to the bass' ground; the jack socket shield. Providing the actives' amp chips can stand it connecting 2 more batts, one in series with each of the originals, should be OK. That gives 36 Volts: not many amp chips will stand 36 Volts across them.

    Actives with 1 battery will usually artificially generate the zero volts rail. That means 3 batts (27 Volts) could be series connected and still use the same principle: so could 4 for that matter.

    Beware that you do not exceed the ratings of other components such as electrolytic capacitors. A 9 Volt system may well use 10 Volt capacitors. Put 18 Volts across them and you've got a, well, bang!


    Rockin John

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