Octave Phono Module

The Octave Phono Module is based on the idea of offering ambitious analog listeners a highly specialized and at the same time flexible phono preamplifier. The experience of over three decades in the development of innovative preamplifiers made the design of a modern tube hybrid phono preamplifier almost a necessity.

Tube based external phono preamplifiers are the preference of music lovers who prefer the sonic virtues of analogue reproduction. Modern MC (moving coil) pickup systems, with their low output signal, cannot be connected to a tube based phono stage without an additional step up transformer to keep the total noise to an acceptable level.

When OCTAVE was founded, Andreas Hofmann began developing phonostage preamplifiers with an electronic MC input, because transformers are very sensitive to magnetic stray fields and they are limited in respect of the load impedance and the amplification factor. The OCTAVE Phono Module is a full feature phone preamplifier which allows the use of three different Input modules and three different Output modules.

The three Input modules can be used simultaneously. An single-ended (RCA) MM (moving magnet) module, with switchable Input Impedance 1k Ohm and 47k Ohm. An single-ended (RCA) MC module featuring switchable Input Impedance between 50 to 1k Ohm, with Gain adjustable in two steps.

It can be selected from a plurality of input modules. Not only phono, but also line modules available.

There is a balanced MC Module with XLR input jacks, featuring the same Impedance and Gain adjustment as in the unbalanced MC module. The Phono RIAA equalization stage is realized with a tube circuit based on the phono section of the highly-regarded OCTAVE HP 500 SE preamplifier. The RIAA Stage utilizes three tubes to ensure the high gain required by the RIAA correction.The specific configuration, with solid-state devices in the MC input and tubes in the RIAA output stage, allows the realization of a phono preamplifier which surpasses any and all tube designs in respect to spectral clarity and the signal to noise ratio.

The optional Output modules complete the OCTAVE Phono Module: There is the standard single-ended Output Module featuring dual RCA outputs, one with fixed level, the other with passive regulation. The next is the single-ended “ Direct Drive “ Module, also with dual RCA outputs, where the regulated output is buffered to reach a low output resistance to allow for driving a power amplifier directly.

There is also the Balanced (XLR) “Direct Drive” Module, featuring complex circuitry containing a tube and some integrated circuits that form a perfect balanced converter. This regulated output is also able to drive any power amplifier directly, while also allowing the level of the balanced output to be reduced to operate with the balanced line level inputs of a preamplifier. The OCTAVE Phono Module utilizes an external power supply.

Of course, the Phono Module has power management with soft-start electronics.

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.

Output Modules

The Octave Phono Module offers the option of installing or retrofitting various output modules.

The three different output modules are only available for the Octave Phono Module. Whether "Standard" or "Direct Drive", Cinch or XLR, each phono system can be adjusted to the individual needs and preferences of the listener using the outputs.

OUT 1: RCA standard

OUT 1 is a Cinch standard output module with double output 1 x fixed, 1 x variable. The adjustable output can be used for external headphone amplifiers or as a direct recording output for tape or PC. The unregulated output is intended for connection to high-level inputs of a pre-integrated amplifier.

OUT 2: RCA Direct Drive

With the tube output module OUT 2 it is possible to directly control asymmetrical power amplifiers with the variable output. The fixed output is intended for connection to high level inputs.

OUT 3: XLR Direct Drive

With the tube output module OUT 3 it is possible to directly control symmetrical power amplifiers with the variable output. The fixed output is intended for connection to high level inputs.

Black Box Preamp

The Black Box Preamp is a passive power supply enlargement for the Octave Phono Module with an increase in capacity by a factor of six. The Black Box Preamp significantly increases the dynamics and tonal stability of the Phono Module. The sound body gains contour and the spatial image becomes deeper.

• Basic model: Phono Module
• Options: Input and output modules; Remote control when used as a preamplifier
• Design: Silver or Black
• Tube complement: 1 x ECC88, 1 x ECC81, 1 x ECC83
• Dimensions Preamplifier / Power Supply: 437 x 83 x 487 mm / 110 x 77 x 277 mm (W x H x D)
• Weight Preamplifier / Power Supply: 7.0 kg / 3.0 kg
• Input and Output modules selectable: Input modules IN1 - IN9, Output modules OUT1 - OUT3
• Special connector for Black Box Preamp: Special connection for the passive Power Supply enlargement Black Box Preamp
• Double output: One fixed output (RCA), one variable output (RCA or XLR)
• Tolerance RIAA equalization: +/- 0.2 dB / 10 Hz - 50 KHz
• Crosstalk attenuation left to right / phono: > -60 dB / 1 KHz
• Crosstalk attenuation left to right / line: > -80 dB / 1 KHz
• Subsonic filter cut-off frequency: 15 Hz / -3 dB; -12 dB / Oktave