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

DBX compressor as a preamp

Discussion in 'Effects [BG]' started by panazza, May 5, 2005.


  1. panazza

    panazza

    Nov 23, 2003
    italy
    is it possible to use a DBX compressor (such as a 266xl or a 166a) as a preamp? going like this:

    bass----compressor----power amp.

    ?
     
  2. MODNY

    MODNY Guest

    Nov 9, 2004
    well

    i would imagine this would werk if u have a onboard pre-amp on the bass itself

    if not

    then i wont have very much control i would imagine

    i could be wrong though
     
  3. Yeah...well, maybe...probably not...no.

    A compressor is all about controlling gain, not volume. There's input gain which is the signal coming from your bass and the input gain of the compressor...then the compressor does its compressing thang, effectively cutting the volume peaks (making you quieter)...then there's makeup gain, which is intended to make the volume coming out the same as the overall volume coming in...except your peaks are chopped so you sound louder and fuller.

    Some comps have a significant makeup gain, but it is not a volume control. Can it be used as such? Probably, but as MODNY said, you won't have the control you're used to.
     
  4. Finger Blister

    Finger Blister

    Jul 8, 2003
    NO.

    Examples may vary, but hold true.

    Instrument input is about -20 db.
    Compared to the -10/+4 db Line Level I/O's found on your compressor.

    Besides the Impedance would attentuate your signal.
    Line Level Impedances of: 40k Balanced/Unbalanced
    and /or Balanced > 50 kOhm, unbalanced > 25 kOhm

    Typical Bass Preamp Passive Input: 1 Meg Ohms

    Typical Active Input: 47K Ohms (attentuation of about -8 db)