Octave HP700 Vacuum Tube Preamplifier


*Please check with our online customer service team or your local store for stock availability


HP700 - sophisticated valve technology combined with intelligent modularity make this pre-amp future-proof. A valve pre-amp boasting innovative precision technology and a modular concept that allows the listener the freedom to build a system to cater for individual music tastes. Instead of being bound by the fixed audio and technical parameters of the equipment, listeners can adapt the technology of the HP700 to their own requirements and preferences. The result is THE sound - the optimal sound experience for the individual high-end audio system and the individual listener. THE NEXT STEP - A major step toward the ideal of all music lovers.


Options are available for additional cost, for additional Inputs & Outputs, please call for more information.

    In combination with the newly developed high-precision, low-noise supply-voltage stabilizing circuitry, the separate power supply unit for the HP 700 ensures constancy of the audio output even when the mains voltage is subject to wide fluctuations and high interference levels. Added to this, the integrated control logic system guarantees maximum operational reliability and, backed by our exclusive soft-start technologies, ensures the valves and the unit have a life of up to twenty years.

    The multi-channel bypass function allows the HP700 to be integrated into an existing home-theater combination. The logic-controlled input selector circuitry allows selection of the bypass function for an XLR or phono input on the rear panel. The HT signal is present at all three outputs.

    The sophisticated design of the HP 700 makes extremely high demands on the power supply unit. The external power supply unit is magnetically screened and supplies a clean voltage to the HP 700. The screening is also essential to ensure low- noise, low-hum operation of the phono MC input.

    The connection possibilities of the generously configured standard model are rounded off by two user-selectable optional input modules. An optimized input module can be used for unusual applications, for anything from an MC step-up transformer to a transformer-based XLR input module. The plug and play modules can be readily installed or upgraded at any time.

    Next-step technology has also been applied in the redesign of the Phono RIAA amplifier. The further development of the RIAA stage has improved the signal/noise ratio, while simultaneously reducing system-related distortion. The widening of the bandwidth enables accurate RIAA equalization and exploits the full potential of analog reproduction. The wide variety of optional input modules ensures that the optimal input can be installed for every pickup.

    The innovative optional tone control rounds off the HP 700 equipment. The precision valve-based tone control unit guarantees consistency of the sound, even at low volume. Precision adjustment of bass and treble, with a 0.3dB channel separation, allows the tone to be adjusted without impairing the spatial reproduction.

    The frequency-compensated balance control allows channel-separated volume adjustment in 1 dB steps. This technology eliminates any controller-related sound shifts. Using 12-position stepped switches, the setting is longtime stable, with 100% repeatability.

    The unit output can be switched to several zones by manual activation of the outputs. Whether the output is through XLR, phono or all three outputs simultaneously, a total of three output stages can be utilized for separate rooms, different speakers or bi and tri-amping.

    The optional, frequency-compensated 47-position stepped switch ends the debate about the influence of the controller on the quality of the music signal. At 0.1dB, the channel deviation is supreme. Our own in-house development, the volume control design maintains the frequency bandwidth constant throughout the entire control range, reducing controller-related distortion to a scarcely measurable level.

    However, as a result of the mechanical design of the stepped attenuator, the switch positions cannot be controlled using the remote control.

  • Specifications

    3 x RCA, 2 x XLR, 2 x arbitrary

    1 x Bypass RCA (can be switched to IN4 -XLR)

    Outputs 2 x RCA, 1 x XLR, 1 x Monitor / Tape Record (RCA)

    XLR transmission ratio 0 dB XLR pin assignment 1 = ground, 2 = positive, 3 = negative

    Line stage

    Output resistance
    100 / 300 ohms RCA; 150 ohm XLR

    Monitor Out output resistance
    240 ohms

    Maximum output voltage

    Gain factor Gain High
    25 dB = 18,5

    Gain factor Gain Med
    18 dB = 7,8

    Gain factor Gain Low
    12 dB = 4

    Signal-to-noise ratio Gain High -
    98 dB / 38 µV at 3 V output voltage

    Signal-to-noise ratio Gain Med -
    104 dB / 18µV at 3 V output voltage

    Signal-to-noise ratio Gain Low -
    110 dB / 8 µV at 3 V output voltage

    Equivalent noise-level
    14 nV √Hz

    Frequency response Gain High-
    RCA 10 Hz – 200 kHz -0,7 dB, 0,7 Mhz -6 dB

    Frequency response Gain Med-
    RCA 10 Hz – 200 kHz -0,3 dB, 1.3 MHz -6 dB

    Frequency response Gain Low-
    RCA 10 Hz – 200 kHz -0,2 dB, 2,1 MHz -6 dB

    Frequency response
    XLR 10 Hz – 200 kHz -1,5 dB

    Ramp-up time Gain Low
    250 ns

    Ramp-up time Gain Low
    60 V/µs

    Total harmonic distortion, Gain Low, Med, High
    0.01% at 3V on 10 kOhm

    Channel separation
    -90 dB / 1 kHz, Input short-circuited

    Crosstalk between inputs -
    80 dB / RCA, -95 dB XLR / 1kHz

    Input resistance
    50 kOhm

    Channel matching via volume control
    0,5 dB - 70 dB


    RIAA equalization tolerance
    0,3 dB / 15 Hz - 20 kHz

    Corner frequency - subsonic filter
    15 Hz / - 3 dB

    Signal-to-noise ratio -
    75 / - 84 dB / with IN 2 MC Input

    Input sensitivity
    250 µV / 600 µV / with IN 2 MC Input

    Input sensitivity, gain and input resistance depend on input module

    Gain MC Gain Low - Pre Out Gain Low:
    70 dB, Med: 77 dB, High: 83 dB

    Gain MC Gain High- Pre Out Gain Low:
    79 dB, Med: 86 dB, High: 92 dB

    General Facts

    Power consumption: 35 - 60 W

    Weight preamplifier :10 kg

    Weight power supply: 3,8 kg

    Supplied accessories: Power calbe, remote control

    Dimensions of preamplifier (over-all):
    462 x 130 x 480 mm (W x H x D)

    Dimensions of power supply (over-all):
    110 x 90 x 277 mm (W x H x D)

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