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Discussion in 'Effects [BG]' started by TGEvans, Dec 5, 2005.

  1. Can someone explain to me please the difference between compression and optical compression.and also has anyone got any views on the demeter compulator.cheers.
  2. fretlessrock

    fretlessrock Supporting Member

    Aug 8, 2002
    The Demeter is a really nice comp is a small simple package.

    Optical compression is where a photocell is used to do the compressing. A photocell has a sender and a receiver. The sender is a light source and it is modulated by the incoming signal. The receiver is a photo sensor that reacts to the light source. The sensor isn't linear, and as the source gets brighter the sensor will not track the increase at 1:1 forever. The response curve ends up looking like a compressor curve! Viola. Analog compression.
  3. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Yeah - it's pretty elegant, in that you can actually make a compressor that only has a pure-passive, purely-resistive gain reduction element in the signal path! In this case you'd never have unity-gain, though, so there's usually at least a little amp in there for makeup gain.

    Also - like Fretless was saying - the natural gain reduction nonlinearities AND the naturally slightly-sloppy attack and release times (of CdS cells) turn-out to sound very 'musical' and natural.

  4. Hey...this sounds like a tube amp's description...I have a tube amp at home, but only a lowly Hartke Kickback 15 in our practice space.. I was wondering if an optical compressor would warm it up a bit? Sorry to jump in the middle there..
  5. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Sounds to me like what you need is an Aphex Bass Xciter. I'm tellin' ya: It'll make that little Kickback sound like - uh... a BIG Kickback! ..Actually, I really like the Hartke sound.

    The thing-is, the cheaper of an amp you put them on, the more dramatic of a difference those Xciters make! I BET you'll like it!

    I have a nice pro-rig (GK and JBL), and I even hate to run THAT without my Xciter, but it still never ceases to amaze me that it can even make a cheap home stereo into a decent bass rig; it can even make my Tascam Bass Trainer sound good, and those have the worst preamp ever invented!

    "Ya owe it to yourself..."


    (edit) Oh - I should mention that the 'Big Bottom' section of the Xciter IS a compressor, but technically-speaking, it's an 'upward compressor' instead of the usual 'downward' compression - AND it only works on LOW-freqs (just how-low is up to you - that's the 'low tune' control. I set mine on about 5.5 or-so). 'Upward', in this case, means that it won't chop-off any of the bass' natural transients - it works more-and-more as the note decays; a 'regular' compressor works more-and-more as the signal amplitude goes higher.

    (Last time I talked about this, one of our fellows posted that Big Bottom is not a compressor.. I looked into it AHH-gain, and confirmed that yes, it is 'upward compression')

    (edit) Oh - and also: the rackmount version of Big Bottom is an OPTICAL Big Bottom! Cool.