For all you tube and valve lovers this monoblock power amplifier has to be right up there at the pointed end! Back in November 2023 the German high end audio and transformer company Octave, announced their Jubilee Mono Ultimate tube power amplifier. This monoblock push-pull tube design provides an immense power output of 440 watts RMS into 4 ohms from a total of eight KT170 tubes.

This latest ultimate flagship design includes a number of improvements over the earlier Jubilee Mono SE amplifier. The basic idea is the extreme expansion of the power bandwidth and the bass range with their newly developed, highly specialized and oversized high performance output transformer. This bespoke designed oversized transformer uses special wrapping techniques to counteract skin effect. The approach is said to have increased the windings surface area by 50%, providing a power bandwidth of 10 Hz to 100 kHz with little change in distortion. This winding increase and technique “contributes significantly to the incredible resolution and smoothness that characterizes the Jubilee Mono Ultimate in the mid and high frequency range.”

This main output transformer is only one of four that this design uses, the other three supporting; the tubes heaters and two line transformers for the amplifiers main power section.

The main tube driver stages have also been heavily modified in order to maintain exact phase relationships between the in-phase and anti-phase signals that drive the push-pull power stage.

Control, setup and status is available from the amplifiers top panel that uses a digital meter together with LED’s to show tube status and bias conditions. Manual bias setup is selected from this panel with pre-set controls being accessible in the amplifiers rear panel .

The Jubilee Mono Ultimate uses many of the companies special features to include; power management with soft start electronics, a protection system, eco mode, and BIAS setting and display.

Finally, rear panel connectivity includes; switchable balanced XLR and unbalanced RCA line level inputs, a pair of speaker binding posts and a 12VDC remote control trigger.

What’s new:

• KT 170 output tubes
• Oversized ultra broadband output transformer
• Speaker windings using multi-wire technology to minimize the skin effect
• Further developed driver stage with changed tube layout
• Mains transformer unit with 3 mains transformers
• New power supply electrolytics with higher current delivery capability
• BIAS display and setting with significantly higher long-term precision
• Resonance-optimized base construction (8 mm aluminum, 2 mm steel, 50 mm X-MDF)
• Finishes: Black or Silver with wood (Macassar Ebony) or stone (Granite, Slate) inlay

Features:

• Eco Mode: Power saving mode
• Protection System: Inrush current delay (soft start); Protection circuit for device and output tubes
• Power Preselection: 2-stage current adjustment, Low / High
• Bias Control: separate BIAS Adjustment for each power tube
• Inputs: RCA + XLR selectable

For more information visit the Octave web site.

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