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Gibson HP-4 "Transient Suppression"

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  • Gibson HP-4 "Transient Suppression"

    hi Forum folk -

    Does anyone have any insight into the circuitry used in the 2019 Gibson HP-4 dip switch #5 which turns on/off what they call "Transient Suppression"?

    The documentation provided by Gibson says this:

    Transient Suppression (Off=Out of Circuit / On=In Circuit)
    Transients = A sudden, loud spike from the initial attack phase of sound.
    Example: Pick attack or noise.
    ON = Works to suppress the harsh transient noise or spikes which A/D convertors
    can sometimes pass when recording directly into the high impedance input of a
    DAW interface or digital mixer. Due to the inherent input compression of typical
    guitar amplifiers, this circuit is virtually transparent even if left on in the circuit.

    When asked whether they had a circuit diagram to study:
    "We don’t have a file that outlines the precise circuitry of that PCB."

    I have yet to do an experiment on my DAW/Interface, but am wondering if anyone knows what this is actually doing, electronically.


  • #2
    Check out this article I wrote for Guitar Player, it explains what transient suppression is all about.

    I came up with this circuit years ago, so it's in the public domain. Gibson recognized the potential, though, and included it in several Les Paul Standard models. The main use is when feeding guitar into digital audio interfaces, because it lets you obtain a higher average level with a more predictable dynamic range. In a way, it acts similarly to how analog tape "absorbs" transients.
    The first 3 books in "The Musician's Guide to Home Recording" series are available from Hal Leonard and http://www.reverb.com. Listen to my music on http://www.YouTube.com/thecraiganderton, and visit http://www.craiganderton.com. Thanks!