Black Box

The Black-Box is an external Power Supply Booster.

Super Black Box

The Super Black-Box is an external Power Supply Booster with enhanced Capacity.
RE 290

OCTAVE proudly presents the latest evolution of the successful and enduring RE 280 stereo amplifier. The company’s traditional stereo amplifier design has been produced since 1990, having been updated and improved continuously over the years. This progressive development has brought forth an even further improved variant in the form of the new RE 290 power amplifier – an ideal companion for any and all modern high-performance loudspeakers.

The RE 290 based on the stable and reliable electronic circuits of the RE 280 MKII model, while incorporating the benefits of the recently-developed KT120 power tube. The KT120 allows an output power of more than 100 W via two tubes in push-pull mode, while its current capacity is higher compared to the classic KT88 tube designs. Increased stability with difficult, low impedance speakers is achieved through the increased bandwidth and OCTAVE’s specially designed output transformers. Lifelike reproduction of even the most complex orchestral passages in the own home is now possible.

The power bandwidth of the RE 290 ranges from 5 Hz to 85 kHz. The noise level (100μV =-110dB) is so low that even with high efficiency speakers there is no audible hum or noise. The power supply functions are controlled by the exclusive OCTAVE power management circuitry. In combination with the highest quality components manufactured in Europe, this results in a finer-sounding and more stable performance over the entire lifetime of the RE 290 (over 15 years expectancy).

A certain charm of tube amplifiers is the ability to explore the sonic properties of different tube types. Whether rare NOS models or new tubes such as the KT120, the OCTAVE RE 290 allows the use of various pin-compatible output tubes. In order to allow optimal operation of a diverse range of output tubes of different power classes, a switching circuit is included on the rear panel of the amp. The bias of the output tubes can be fine-tuned in three steps. Other features enhancing ease of use and operation include the ECOmode, the optional connection for the external Black Box or Super Black Box capacitance upgrade modules, as well as switchable RCA and XLR inputs.
Basic Model   Stereo Power Amplifier with 2 x 90 Watt
Tube Complement  
4 x KT 88 or KT 120, Driverstage Tubes: 3 x ECC 82
Aluminium silver or Aluminium black
Add On Modules  

  Power Output  

2 x 90/130 Watt into 4 Ohm in High Power Mode

2 x 70/90 Watt into 4 Ohm in Low Power Mode

  Frequency Response  
5 Hz - 85 kHz / - 3 dB
  Total Harmonic Distortion  
< 0,1% at 10 Watt into 4 Ohm
  Signal-to-Noise Ratio  
> 100 dB
  Minimum Speaker Impedance  
2 Ohm
  Gain / Input Sensitivity RCA  
+ 28 dB / 0,8 V

1 x RCA

1 x XLR Input


ECO Mode, Bias Adjustment, Power Management

  icon Download:
Owner's Manual
  General Facts      
  Power Consumption  
200 Watt idle, 400 Watt at full power
  Standard Accessory:  
Power cord, 3 mm Screwdriver for BIAS Adjustment
  Weight   24,5 kg each Amplifier  
  Dimensions (in mm)
invi invi

Black Box Connector

OCTAVE, with the Black Box technology, offers an upgrade path for optimizing the OCTAVE amplifier in respect to the speaker. This flexibility is a unique feature of the OCTAVE brand.

The dynamic and tonal stability of an amplifier is strongly dependent upon the stability and capacity of the power supply, therefore the Black Box and Super Black Box were developed as external upgrades to the OCTAVE amplifiers’ power supply storage capacitors by increasing their capacitance by a factor of 4 (Black Box) or 10 (Super Black Box), respectively. This is a tremendous benefit if the speaker is difficult to drive. Loudspeaker efficiency is made less critical, while the amplifier is enabled to handle speakers with extremely low minimum impedances.  

BIAS Adjustment

The Output stage of the RE 290 operates in Class A/B, and therefore requires an adjustable BIAS regulation. The highly sophisticated yet extremely simple yet accurate BIAS calibration system is accessed on the front panel of the unit. It utilizes external precision bias trim pots and LED confirmation, allowing the user to readily monitor the output tubes and simply correct their bias individually at the top panel - without the need of a micrometer let alone any special knowledge or tools.

The correct BIAS is vital for the constant sound quality of the RE 290. Due to this facility there is no need for a technician to service the RE 290 for changing or tubes or to check their condition. The precision of this user friendly system is within 0.5% accuracy.

Power Management and Protection System

The RE 290 is equipped with a multi-stage Soft-Start/Turn-On protection circuit which extends component as well as tube life considerably by protecting against stress caused by typical high inrush currents during switch-on. The unit starts in a defined sequence, with the Protection System monitoring the RE 290 completely, and activated whenever a malfunction is detected. Once the Protection is activated, the RE 290 is powered down.


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