Dismiss Notice

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

Is it safe?

Discussion in 'Amps and Cabs [BG]' started by Cornbread, Mar 26, 2001.


  1. Cornbread

    Cornbread

    Jun 20, 2000
    Lawrence, Ma
    Is it a good idea to plug an active bass into the passive input of my BA-115? I've been doing that since I got the new bass, and I don't get any distortion or anything. The 15dB cut on the active input seems like too much.
     
  2. Gabu

    Gabu

    Jan 2, 2001
    Lake Elsinore, CA
    I wouldn't second guess the technicians who designed the amps dude. If you have the money to replace it... it's fine to be adventurous. But for me if it was just a matter of a bit more volume it aint worth it.
     
  3. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    Don't worry, you can't damage anything.
    Those inputs differ only in impedance. The passive input is designed for higher impedances than the active input, since a passive bass has a much higher impedance that a bass with active electronics. The amp input has to have a tenfold higher impedance than the source (your bass) to avoid misalignment, which can cause some loss of highs. Sometimes, as in your amp, the active input is dampened by e.g. 15 dB to accommodate active basses with very high output.
     
  4. AssMan

    AssMan

    Dec 2, 2000
    Minnesota, USA
    What bass do you have? It shouldn't hurt anything. If it is hurting something, you'll hear it. Also Does amp have a pad or a seprate input for active basses? My old ampeg b3 had a -12db pad for active basses which hurt the basses sound, and in order to get the volume I wanted, I'd have to crank the gain which would make the amp noisey, so I just never used the pad. My bass has a low output for being active due to the passive pick-ups.
     
  5. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    FYI: In an active bass the electronics (active preamp/EQ) determine the amount of output, not the (passiv) pickups themselves.
     
  6. Oysterman

    Oysterman

    Mar 30, 2000
    Sweden
    Well, the pickups matter as well. My Yamaha bass is active, but a lot lower in volume when set at full than a regular Fender (for instance my MIM J). I don't think the preamp was design to weaken the signal... :) I wonder if there would be much of a signal at all if i tried to bypass the preamp.
     
  7. Hey Cornbread, what number on your volume dial do you usually play at? I've found that playing through the active input with an active bass sounds better at high volumes, while playing an active bass through the passive input can sound better at low volume levels.

    Mike J.
     
  8. Cornbread

    Cornbread

    Jun 20, 2000
    Lawrence, Ma
    On my amp, I usually have the gain and master knobs at about 10-11 o'clock.

    So, basically, what I'm reading is that it's ok to use the passive input unless I have a really high output bass (perhaps 18V electronics?).
     
  9. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    Yes, even with a high output bass. :)
     
  10. Ditto to what JMX said. Also just try the gain and master volume cotrols at different settings.

    Mike J.
     
  11. Brad Johnson

    Brad Johnson Commercial User

    Mar 8, 2000
    Gaithersburg, Md
    Boom Bass Cabinets, DR strings
  12. AssMan

    AssMan

    Dec 2, 2000
    Minnesota, USA
    It a combination of the two. But my preamp is a lower output preamp anyway.