Octave HP300SE Vacuum Tube Preamplifier


The HP 300 SE is a enhanced version of the HP 300 MKII. The HP 300 SE does not replace the HP 300 MKII, this model extends our range of Preamps.


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

The HP 300 SE offers more flexibility in the connections and sonic benefits due to some improvements in the Power Supply and the Output stage of the Line Amplifier.
The HP 300 SE has two independent XLR Inputs, three RCA Inputs, one Monitor Output, two RCA Outputs and one XLR Output. The Gain is switchable in three steps, this allow to set the optimum Gain and regulation Ratio depending on the efficiency of the Loudspeaker.

The new designed Line Amp has a extremely high Signal to Noise Ratio. Noise is not only a characteristic of the tubes, a significant contribution is coming from the mains, respectively the Power supply design of a Preamp.

The Power supply of the HP 300 SE consists of the external transformer with optimized isolation characteristic, and the precise ultra low noise Voltage regulators of the main unit. Both systems are match to each and help reducing the Noise of the Lime Amplifier effectively.

The Balanced Output is realized with a highly symmetrical Output Transformer. The Transformer offers the possibility to connect or disconnect the Ground connection to the Power Amplifier.

The feature helps to reduce disturbing mains induced currents that usually flow in the Ground of the Signal connection. Both Outputs offer very low Output Resistances. Connecting cables up to 5 - 10 meter is without negative influence. A helpful feature in modern Hifi combinations is the Home Theatre Bypass Function.

The HP 300 SE offers this feature, with the additional possibility to select the Bypass Input from a RCA Input to a XLR Input. The Monitor Output is buffered and can be used to drive an external headphone Amp, the Analog Input of a Computer or similar. Phono MC is available optional.

Basic Model: HP 300 SE, optional: Phono MC
Tube Complement: Line-Platine: ECC 81 und ECC 88; Phono: ECC 81
Aluminium silver or Aluminium black

Gain high: 
25 dB = 18,5
Gain med:
19 dB = 8,8
Gain low: 12 dB = 4
Frequency Response Gain:
high 10 Hz - 200 kHz - 1,5 dB
Total Harmonic Distortion: Gain high 0.03%
S / N Ratio: Gain high - 92 dB
S / N Ratio: Gain low -108 dB
Left/Right Crosstalk: 90 dB 1 kHz
Input to Input Crosstalk: 100 dB 1 kHz
Input Impedance: 100 kOhm
Output Impedance: 50 Ohm cinch; 150 Ohm XLR
Channel Balance: 0.5 dB - 70 dB

Inputs: 3 x Cinch, 2 x XLR, 1 x Phono Option
Outputs: 2 x Cinch, 1 x XLR, 1 x Monitor
Features: HT Bypass, Sym. Inputs and Outputs, Monitor Out

RIAA-Equalization Accuracy: 0,3 dB 15 Hz - 20 kHz
Corner Frequency Subsonic Filter: 15 Hz / - 3 dB
Input Impedance: 30 - 1000 Ohm
Input Sensitivity: 0.2 mV / 0.7 mV
Gain low: 58 dB
Gain high: 67 dB
Signal-to-Noise Ratio (weighted): - 75 dB