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How to connect-up: compressor and preamp?

Discussion in 'Amps and Cabs [BG]' started by Rockin John, May 26, 2005.


  1. Please, what is the best way to connect-up?

    Do I connect the bass to the compressor then to the tone shaping preamp then to the power amp?

    Or do I do it the other way around: bass to tone shaping then to compressor then to power amp?

    Reason for doing it either way appreciated.

    I already have the 19" rack compressor and will have a 19" preamp fairly soon (like the RMP-1 as the subject of another thread in Amps).

    Thanks.

    John
     
  2. IMHO:

    Bass > Compressor > PreAmp > PowerAmp.
     
  3. Yea, this is the way to go. You'll get more out of your pre this way since it'll be shaping the already compressed signal. Some may disagree, but this is how I run my rig and I dig it. But I don't rely on my compressor to get my sound.
     
  4. remo

    remo

    Jan 15, 2005
    ..unless the preamp has an FX Loop ;) then use that.
     
  5. Agreed. ;)

    (I think :meh: )
     
  6. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    I've never liked the sound of compressors in the effects loop. I suggest you put it before the preamp.
     
  7. Yes, that was my slight doubt. :meh: :meh:

    I guess the answer would be to try both.

    One man's drink etc etc. ;) ;)
     
  8. maxvalentino

    maxvalentino Endorsing Artist Godin Guitars/ Thomastik-Infeld

    As much as it has to do with your "preference" for the placement of a device (begining, middle, or end of the signal chain), the capabilities of the device in question have great bearing on where one can put it.

    Most rack devices, especially compressors, are designed for -10dBu line level signals. Plugging an instrument, with its' instrument level -20dBu signal, will not yield the most desirable or efficient results.

    Similarily, dynamics processors such as compressors are designed to take the entire signal to process optimumly. Depending on what type of fx loop your amp has (serial or parallel) this will greatly effect the efficiency on the compressor.
    If the loop is serial the only other condition would be is it designed as a line level loop or instrument level loop (the fx loops on the BBE BMax pre's as well as the Alembic FX1 are instrument level and will not worrk very well with line level devices....)
    If it is parallel, then hopefully it will also has a mix control which can be dialed to 100%wet....

    Placing a compressor at the front of the chain is a common approach, as it can be used for both dynamic control (altho' manual control of one's dynamics is preferable) as well as tone-enhancing device in addition to giving a smooth, controlled signal to any other "stops" along the signal path. Of course, if the device cannot handle instrument level signals quietly and efficiently, this point is moot.
    Placing the compressor first is a common setup for live work.
    Although, many players place a compressor last in their setups to act as limiter...affording a final stage of protection to their amps and speakers.

    For recording, it most common to place the compressor at the end of the signal chain. This is done to smooth out any spikes or curves to the signal before going to tape (or HD). Many players use the compressor last as a means of bumping the signal up to a +4dBu level in which it can be sent to the recording device direct bypassing any further gain staging. This placement also insures a stable, hot signal to recording, but can act as a limiter to prevent distortion (very bad in digital recording) at the record inputs.

    Max
     
  9. OK. Thanks.

    As someone naive in these matters it seemed more sense to place the compressor first, following the bass.

    I tried that but can't get the compressor to compress due to lack of signal level (as it appears to me). Place it after the tone shaping, and no problem there.

    (Fender Jazz USA Dlx 5 into a Behringer compressor. Ooooooh, not supposed to say the 'B' word, am I...?).

    OK, too, I'm going in unbalanced into the balanced I/P so there's half the signal gone before I start (as far as the compressor is concerned). I suppose I could use some kind of line level DI box but really don't want to increase the peripheral kit; quite the opposite in fact.

    Hmm, OK. Perhaps more experimenting required. Perhaps I should read the handbook again.

    Thanks folks.

    John