Octave HP 700 SE Tube Preamplifier

The HP 700 SE is a tube preamplifier that features innovative precision technology as well as sonic refinements to the output stage. Like its predecessor, the HP 700, it meets the listener's individual wishes for their high-end combination thanks to its modular freedom. The new SE version now has two parallel XLR sockets next to the two RCA outputs on the back, allowing all variants of bi-amping. But even more important are the modifications to the actual Class A output stage.

Refined tube technology and intelligent modular technology made the HP 700 future-proof right from the start - an innovation in the market. Now it was time to push the innovative HP 700 even further in terms of sound and technology. The new HP 700 SE is a tube preamplifier that features both new precision technology and tonal refinements of the output stage. Like its predecessor, its modular freedom meets the listener's individual demand for truly customized high-end setup. Instead of being bound by the fixed audio and technical parameters of the equipment, listeners can adapt the technology of the HP 700 SE to their individual requirements and preferences.

In the new SE version, there are now two parallel XLR sockets next to the two RCA outputs on the back panel, allowing all types of bi-amping. But the modifications of the actual Class-A-output stage are even more important. The search for the even finer sound took place with the help of extremely time-consuming and complex measurements, along with accompanying listening sessions. These difficult adjustments are responsible for the tonal improvements, especially the mid-tone of the pre-amplifier. The tube configuration remains unchanged compared to the predecessor HP 700, as do all the other tried-and-tested technical refinements on this incomparable preamp:

PRECISION TECHNOLOGY IN THE LINE STAGE

The term "precision technology" stands for a circuit in tube technology that has an extreme bandwidth up to 1 MHz, an impressively low output resistance of 100 ohms and sensationally low distortion of 0.001 %. Three amplification settings, combined with selectable output impedance, enable perfect fine-tuning of the HP 700 SE to the characteristics of the sound reproduction chain. The three-stage amplification settings allow optimal matching of the volume control to the efficiency of the speaker.

PSU TECHNOLOGY

In combination with the newly developed, high-precision, low-noise supply-voltage stabilizing circuitry, the separate, magnetically shielded, outboard power supply of the HP 700 SE (essential for the low-noise and low-hum function of the MC-input) 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 tubes and the unit have a life of up to twenty years.

BYPASS

The multi-channel bypass function allows the HP 700 SE to be integrated into an existing home-theater system. The logic-controlled input selector circuitry enables activation of the bypass function for an XLR or RCA input on the preamp's rear panel. The Home Cinema signal is present at all three outputs.

ADDITIONAL INDIVIDUALIZATION OPTIONS: MODULAR INPUTS

The connection possibilities of the generously configured standard HP 700 SE model are rounded off by two user-selectable, optional input modules. An optimized input module can be used for unique 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. PHONO Innovative 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 any cartridge.

TONE CONTROL

PRECISON TONE CONTROL

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

BALANCE CONTROL

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 long-time stable, with 100 % repeatability.

OUTPUT SELECTOR SWITCH

The HP 700 SE output can be switched to multiple zones by manual activation of the outputs. Whether the output is through XLR, RCA or all three outputs simultaneously, a total of three output stages can be utilized for separate rooms, different speakers or bi and tri-amping.

STEPPED VOLUME CONTROL

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 0.1 dB, the channel deviation is supreme. Our own in-house development, the volume control design constantly maintains the frequency bandwidth throughout the entire control range, reducing controller-related distortion to a barely measurable level. However, as a result of the mechanical design of the stepped attenuator, the switch positions cannot be controlled via the remote control.

Of course, the HP 700 SE has power management with soft start electronics, gain selector, monitor/record output and the HT bypass.

Phono RIAA HP 700 (SE):

The further development of the RIAA stage of the HP 700 (SE) increases the signal-to-noise ratio while reducing system-related equalization errors. Increasing the bandwidth enables precise RIAA equalization and explores the full potential of analog playback. The Phono RIAA is equipped with a switchable subsonic filter.

Input Modules

The Octave Phono Module and the Octave HP 700 (SE) preamplifier offer the option of installing or retrofitting various input modules.

The range of input modules ranges from electronic high level and MC inputs, symmetrical and unbalanced, to input modules for high level and phono MC in transformer technology. Transformer-coupled inputs (step up transformers) are the optimal solution for the highest quality natural reproduction.

This modular flexibility means that every high-end system can be adjusted to the individual needs and preferences of the listener.

Phono Input Module IN 1: RCA MM Input Module

IN 1 is an analog phono input for MM pickup cartridge systems. Two input resistances can be set on the module, 47 kohm for MM systems and 1 kohm for MC high-output systems.

Phono Input modul IN 2: Cinch MC Input modul

IN 2 is an analog phono input for MC pickup cartridge systems. This MC input can be switched into two amplifier levels. The input resistance can vary within the range of 62–1000 ohms.

Phono input module IN 3: XLR MC input module
IN 3 is a balanced phono input for MC pickup systems. This MC input can be switched in two levels of gain. The input impedance can be varied in the range 60 – 1000 ohms.

High level input module IN 4: XLR / RCA input module switchable

IN 4 is a LINE IN module that can be used either as an additional XLR or as an additional RCA input. The switch from XLR to Cinch is done via a pressure switch on the back.

Phono input module IN 6: RCA MC transformer input module

IN 6 is a step up transformer for low-resistance MC systems. The transmission factor can be switched between 15 and 30. The Gain 30 position is ideal for classic low output MC systems with a level of around 300 µV, the Gain 15 position is optimally tuned for all modern MC systems that deliver a level between 0.5 and 1 mV.

Phono input module IN 7: XLR MC transformer input module

IN 7 is a step up transformer with symmetrical inputs with a transfer factor of 1:20. A symmetrical coupling of the pickup brings advantages in terms of the signal-to-noise ratio if the signal cable to the phono input is relatively long and if the highest demands are placed on tonal purity.

High level input module IN 8: XLR line transformer input module

IN 8 is a line input module for XLR, with a balanced input transformer. The ground connection of the XLR input and the preamplifier can be separated using a switch on the module board. Due to the transformer coupling, this module is the ideal link between modern DACs, music servers, CD players, etc.

High level input module IN 9: RCA line transformer input module

IN 9 is a line input module for RCA, with an unbalanced input transformer. The ground connection of the RCA input and the preamplifier can be separated using a switch on the module board. Due to the transformer coupling, this module is the ideal link between modern DACs, music servers, CD players, etc.

Stepped Attenuator

The optional, frequency-compensated 47-pin stepped attenuator ends the discussion about the control's sonic influence on the quality of the music signal. The channel deviation is beyond any doubt at 0.1 dB. With the controller design we developed, the frequency bandwidth remains constant over the entire control range and controller-related distortions are reduced to a barely measurable level.

Control Module

Combined sound and level control unit with integrated output selection for HP 700 (SE) (Control Module). The optional control unit for the HP 700 (SE) includes balance and tone controls and an output selector switch.

• Basic model: HP 700 SE Line
• Options: Phono RIAA unit, 8 input modules, 47-pin step switch for volume, control unit
• Design: Silver or Black
• Tube complement: Line: ECC82, 2 x EF800; Phono: ECC83, ECC81, ECC88; Control modul: ECC88
• Inputs: 3 x RCA, 2 x XLR, 2 x free selectable, 1 x Bypass RCA
• Outputs: 2 x RCA, 1 x XLR, 1 x monitor / tape record (RCA)
• Dimensions Preamplifier / Power Supply: 462 x 130 x 480 mm / 110 x 90 x 277 mm (W x H x D)
• Weight Preamplifier / Power Supply: 10.0 kg / 3.8 kg
• External power supply
• Soft start control electronics: Providing maximum tube life and trouble-free switching on and off
• 3 levels of amplification can be selected: Adaptation to the efficiency of the speaker
• XLR outputs with transformers: Prevent hum disturbances
• Freely selectable inputs By modular technology
• Option Control Modul: Tone and balance control, output selector switch
• HT Bypass (optional): Bypass-function for multichannel/home cinema
• Two parallel XLR outputs: for Bi-Amping
• Gain factor: High: 25 dB = 18.5 / Med: 18 dB = 7.8 / Low: 12 dB = 4
• Frequency response: High: 10 Hz - 200 kHz -0.7 dB / Med: 10 Hz - 200 kHz -0.3 dB / Low: 10 Hz - 200 kHz -0.2 dB
• Total harmonic distortion: 0.01% at 3V on 10 kOhm
• Signal-to-noise ratio: High: -98 dB / 38 µV; Med: -104 dB / 18 µV; Low: -110 dB / 8 µV