Octave · Preamplifiers
HP 300 SE
The HP 300 SE is a tube line preamplifier with an external power supply, balanced XLR output, and three selectable gain levels.
fig. 01 · preamplifiers
HP 300 SE
current
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From Octave
An external mains transformer with an optimized filter feeds low-noise voltage regulators inside the preamplifier chassis, cutting the noise and interference that would otherwise couple into the ECC81 and ECC88 line stage tubes. The balanced XLR output runs through a precision transformer that can switch its ground connection on or off, useful for eliminating leakage current between connected components.
Three gain settings, Low at 12dB, Med at 19dB, and High at 25dB, let you match the preamp's output to your amplifier's sensitivity. Both the XLR and RCA outputs run low enough output resistance to handle cable runs up to 10 meters to the power amplifier without signal loss.
The rear panel holds two independent XLR inputs, three RCA inputs (one switchable to a phono input with the optional MC or MM board), and a monitor output for a headphone amp or recording device. A multi-channel bypass lets the HP 300 SE sit inside a home theater system, passing an RCA or XLR input straight through to the outputs.
Specifications
| Basic model | HP 300 SE Line |
|---|---|
| Options | Phono MC or MM |
| Design | Silver or Black |
| Tube complement | Line: ECC81, ECC88; Phono: ECC81 |
| Inputs | 3 x RCA (one is phono with the option phono otherwise it is a line level input) / 2 x XLR |
| Outputs | 2 x RCA, 1 x XLR, 1 x Monitor (RCA) |
| Dimensions Preamp / Power Supply | 438 x 78 x 390 mm / 110 x 77 x 277 mm (W x H x D) |
| Weight Preamp / Power Supply | 9.0 kg / 3.0 kg |
| Protection system | Protection circuit for device and tubes |
| Amplification selectable in 3 levels | Adaptation to the efficiency of the speaker |
| HT Bypass | Bypass mode for multi-channel receiver / TV |
| Gain factor | High: 25 dB = 18.5 / Med: 19 dB = 8.8 / Low: 12 dB = 4 |
| Frequency Response | High: 10 Hz - 200 kHz -0.1 dB; Med: 10 Hz - 200 kHz -0.25 dB; Low: 10 Hz - 200 kHz -1,5 dB |
| Total harmonic distortion Low | Med | High | 0.005% | 0.007% | 0.03% at 3V / 7.5 kOhm |
| Signal-to-noise ratio | High: -92 dB; Med: -100 dB; Low: -108 dB |