Octave Jubilee 300 B Monoblock Power Amplifier
56 700,00 €
Octave Jubilee 300 B is a single-ended Class A valve monoblock power amplifier for high-end stereo systems. Three parallel 300B valves provide selectable output power from 15 to 30 W. A separate 7 Hz heater generator for each valve enables their parallel operation. RCA and balanced XLR inputs simplify connection to different preamplifiers.
Octave Jubilee 300 B is a single-ended 300B valve monoblock power amplifier designed for a high-end stereo system. Each channel uses three 300B power valves operating in parallel. Output power is selectable from 15 to 30 W. A stereo system requires two monoblock amplifiers.
This model is intended for listeners who prefer directly heated triode valves and Class A operation. Selectable power, gain and bias current allow the amplifier to be matched more precisely to a particular system.
Power supply and valve heating
A regulated electronic power supply is used instead of a choke-based power-supply circuit. The heater and operating voltages are controlled electronically, reducing the effect of fluctuations in mains voltage on amplifier operation.
A separate 7 Hz generator supplies each 300B valve with its own individually regulated pure-sine-wave heater voltage. This arrangement allows three directly heated triode valves to operate in parallel. The design is also intended to reduce mains-frequency ripple and high-frequency interference.
Inputs and speaker connections
Each monoblock has one line-level RCA input and one balanced XLR input. Use RCA with an unbalanced preamplifier output. Choose XLR when the source or preamplifier provides a balanced output.
Each monoblock receives the signal for one stereo channel. Connect the speaker to the appropriate 4- or 8-ohm output, following the speaker’s nominal impedance and connection recommendations.
Gain and bias settings
Low and high gain modes are available. Low gain suits a high-level source or speakers with sensitivity above 88 dB. It also provides the higher stated signal-to-noise ratio.
High gain reduces the required input voltage to 0.5 V, which is useful when the preamplifier signal is weaker. Gain selection and valve bias adjustment are separate functions.
The bias meter allows all three output valves to be checked. The selector offers low, medium and high positions, corresponding to 25, 50 and 70 mA of bias current for each 300B valve.
Factory system-expansion options
The factory bi-amping option is intended for systems using a separate bass amplifier. Level adjustment helps match the sensitivity of the two amplifiers, while a switchable filter limits frequencies below 100 Hz sent to this monoblock.
A separate factory trigger option allows the power amplifier to switch on with the preamplifier. The bi-amping and trigger functions cannot be installed later and must be specified when the amplifier is manufactured.
Placement
Each amplifier weighs 60 kg and therefore needs a support rated for this load. The two monoblocks can be positioned symmetrically, with sufficient open space for heat from the valves to dissipate. Do not cover the units or place them in an unventilated cabinet.
Technical specifications
| Type | Single-ended Class A valve monoblock power amplifier |
|---|---|
| Stereo configuration | Two monoblock amplifiers |
| Power valves | 3 × 300B per monoblock, connected in parallel |
| Output power | 15-30 W per channel, selectable |
| Power bandwidth | 20 Hz-50 kHz at -3 dB |
| Low gain | 19.5 dB into 4 ohms; 22.5 dB into 8 ohms |
| High gain | 30 dB into 4 ohms; 33 dB into 8 ohms |
| Signal-to-noise ratio at 20 W | >100 dB in high mode; >110 dB in low mode |
| Damping factor | 4.5 |
| Input sensitivity | 0.5 V in high mode; 1.7 V in low mode |
| Line inputs | 1 × RCA; 1 × balanced XLR |
| Speaker outputs | 4 and 8 ohms |
| Control functions | Low and high gain, ECO mode |
| Bias control | Selector and meter for three power valves |
| Bias positions | Low – 25 mA; medium – 50 mA; high – 70 mA per valve |
| Power supply | Regulated electronic design without a choke-based power-supply circuit |
| Valve heating | Separate regulated 7 Hz pure-sine-wave voltage for each 300B valve |
| Power consumption | 400 W at full output power |
| Dimensions | 660 × 240 × 400 mm |
| Weight | 60 kg per amplifier |
| Finish | Silver |
| Factory options | Bi-amping with level adjustment and filter; remote trigger |
FAQ
Will 15-30 W be enough for my speakers?
That depends on speaker sensitivity, impedance, room size and listening level. The power rating alone does not confirm compatibility with every speaker.
Which input should I use?
Choose the connection that matches the preamplifier output. A balanced connection is useful with longer cables, while RCA is used for an unbalanced output.
Which gain mode should I try first?
Start with low gain when using a strong source signal or sensitive speakers. Choose high gain when the system requires greater voltage gain.
How should I position the monoblocks?
Provide each 60 kg unit with a strong, stable support. Leave open space above the valves and around the enclosure so heat can escape.
Can the bi-amping function be installed later?
No. This function and the remote trigger are factory-only options. They must be selected before the individual amplifier is manufactured.
