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  • This product is updated.

    Current version — shift-line.com/olympic

    Shift Line OLYMPIC MkIII

    Tube bass preamplifier with IR-based cabinet simulation

    The device is out of production. Remaining units are available through our dealers.

    OLYMPIC MkIII is the third revision of our renowned tube bass preamplifier, featuring an outstanding sonic character and top-notch build quality. We have combined the classic tube bass sound with modern audio processing technologies, creating a true “Swiss Army knife” for bass players as a result. Dialing in your preferred sound and taking it anywhere with you has never been this easy! The preamp has extensive commutation capabilities and sports an Impulse Response Convolution technology-based cabinet simulator which captures all the characteristic nuances of a real bass cabinet.

    Inputs & Outputs:

    1. IN is the preamp’s 1/4” jack audio input.
    2. THRU is a 1/4” direct-through buffered output jack. The signal from this output is unprocessed. It duplicates the signal from the IN jack.
    3. SEND is a 1/4” output jack that allows to send out the post-EQ signal for external processing. SEND can also be used as an additional output.
    4. RETURN is a 1/4” input jack that allows externally processed signal to be routed back into the preamp (using both SEND and RETURN allows to set up a series effects loop).
    5. OUT is the preamp’s main 1/4” output, designed to connect the preamp to a power amplifier (RETURN or POWER AMP IN on bass amplifiers, INPUT on power amplifiers).
    6. AUX IN is a 1/8” input for an external sound source (the signal from this input is only heard through the PHONES output).
    7. PHONES is a 1/8” headphones output.
    8. BALANCED OUT is an XLR balanced output.
    9. POWER IN is the preamp’s power supply input with a 2.1mm/5.5mm diameter.


    1. The GAIN controls the preamp’s input signal amplification. With this control, you can go from a crystal-clear sound all the way to a classic California-style overdrive.
    2. The BASS, MIDDLE and TREBLE knobs constitute a classic 3-band passive EQ with a mild frequency correction effect and a characteristic mid scoop.
    3. The MASTER knob controls the volume of the signal coming from the OUT jack.
    4. The VOLUME knob controls the volume of the signal coming from the PHONES and BALANCED OUT jacks.
      The MASTER and VOLUME knobs work independently from each other.
    5. The HI switch controls the signal’s high frequency harmonic content. The “+” position accentuates the highs and the attack. The ”-” position provides a milder sound by cutting the high frequencies. The neutral position does not affect the signal in any way.
    6. The GND switch allows to override “ground loops” that can negatively affect the signal when using XLR connections. In the lower position of the switch, the preamp’s “ground” is connected to the signal receiver’s “ground”. In the middle position, the “grounds” are disconnected. In the upper position, the “grounds” are connected and an additional filter is used to remove interference.
      The optimal setting of the GND switch is selected by ear: there should be a minimum amount of 50Hz hum and interference.
    7. The CAB switch selects the cabinet type used for cabinet simulation. The upper position of the switch selects the SUNN 200s (2x15) impulse. The lower position selects the AMPEG SVT-810E (8x10) impulse. In the central position, cabinet simulation is disengaged.
      Cabinet simulation affects the BALANCED OUT and PHONES outputs. It does not affect the preamp’s main OUT.

    Technical Specifications:

    • IN: mono, unbalanced, -20dB, 1 MOhm input impedance.
    • THRU: mono, unbalanced, -20dB, 1 kOhm output impedance.
    • SEND: mono, unbalanced, -10dB, 1 kOhm output impedance.
    • RETURN: mono, unbalanced, -10dB, 1 MOhm input impedance.
    • OUT: mono, unbalanced, +20dB, 1 kOhm output impedance.
    • XLR: mono, balanced, +10dB, 1 kOhm output impedance.
    • AUX: stereo, unbalanced, 0dB, 10 kOhm input impedance.
    • PHONES: stereo, unbalanced, +10dB, 10 Ohm output impedance.
    • POWER: 12V DC 600mA, negative tip.
      Use only regulated power supply units.
    • Dimensions (L x W x H): 122 x 102 x 55 mm (4.8 x 4 x 2.2”)
    • Unit weight: 480 g (1.06 lbs)
    • PSU weight: 120 g (0.26 lbs)

    Delivery Set:

    • OLYMPIC MkIII preamplifier;
    • 12V DC 1000mA PSU with 4 changeable plugs;
    • User guide.