Jubilee 300 B

Our objective was to develop a 300B amplifier that provides enough power for most speakers, while not interfering with the classic 300B circuit. It was not about power for the sake of power, but about providing the 300B with a perfect environment that enhances the tonal qualities of this tube.

The concept of a 300B single-ended amplifier delivering 20-30W output power with three power tubes in indirect parallel operation was thus born.

There is a fundamental problem regarding "direct" heating of the triodes:

Unlike indirectly heated tubes (such as the KT88, KT120, etc.), directly heated triodes cannot operate directly in parallel because of the complex demands on the heating system needed increase output power.

The typical 50 Hz AC heater voltage would cause unacceptably high hum and power disturbances in the speaker. Although DC heating eliminates the hum, it also limits the sonic potential of the 300B.

Octave's solution:

We have developed a 7 Hz power generator that supplies each of the three 300B tubes with a separate, regulated 7 Hz pure sine wave heating voltage.

• This makes it possible to connect several 300B tubes in parallel.

• Sound-affecting ripple and RF disturbances of the line frequency are completely eliminated.

• Heating and operating voltage are electronically controlled, sound instabilities due the fluctuating mains voltage is a thing of the past.

• Only then can the tonal potential of the 300B be fully exploited. The 300B tubes will now operate in the optimized region and can fully develop their tonal qualities. Now it becomes clear why she is called the "queen" of tubes. 

Thus, the Octave Jubilee 300 B is an absolutely modern and uncompromising implementation of arguably the finest amplification technology in the high-end sector. The amp offers an emotional, smooth, highresolution, dynamic and expansive triode sound, not only in the mid/high frequency range, but for the first time, completely across the full audio band.

Jubilee 300 B, a new generation of single ended amplifier technology without limitations. 

Monoamplifier   Jubilee 300 B Power Amplifier
Tube Complement   3 x 300 B / 1 x ECC 82, 1 x EF 800 each Amplifier
Basic Design  
birch burl or nutwood burl
Aluminium silver or Aluminium black

  Output Power  
between 15 and 30 W selectable
  Power bandwidth   20 Hz - 50 kHz / - 3 dB  
  Gain   23dB / @ 4 Ohm  
  Signal to Noise Ratio   > 100 dB @ full Power  
  Damping factor   8  
  Input Sensitivity   0,9 V  

1 x RCA

1 x XLR Input


ECO Mode, Bias Adjustment

  icon Download:
Owners Manual
  General Facts      
  Power Consumption  
400 Watt at full power
60 kg each Amplifier
  Standard Accessory  
Power cord, Screwdriver
H x W x D = 660 mm x 240 mm x 400 mm
» Regulated electronic power supply instead of a choke power supply
» Power generator for triple 7 Hz heating voltage with pure sine wave
» Energy management for supply and heating voltage to extend the lifetime of tube and amplifier
» Protection and overload system to protect the tubes and the amplifier against tube damage and operating errors
» Adjustable BIAS levels to allow the use of different 300 B-tubes: low, medium and high (equivalent to 25mA -50mA and 70mA quiescent current per 300B)
» BIAS meter for controlling the three output tubes
» Speaker output terminals for 4 and 8 ohm speakers
» XLR and RCA inputs
» Trigger/remote switching is optional
» Wood insert (tube plate) and finish is optional
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Diagram: Distortions of the 7 Hz heating voltage compared to 50 Hz mains AC voltage

The distortions of the 7 Hz heating voltage are 200 times lower

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