SONDORO™ series


    control power amplifier (integrated amplifier)
    tube / transistor technology
    150 W / 4 ohm per channel
    isolation-type power transformer
    ensemble PROCAP Golden Gate™ capacitors
    5 inputs, 1 monitor in / out
    ensemble SYNERGIA™ binding posts
    remote and manual control for volume

    The FUOCO SONDORO has all the qualities and attributes to be the pulsating heart of a very high quality music system. With all the necessary controls available both manually and by remote, it offers both ease and the quality of touch. A few bars of music and the FUOCO grabs the listener’s attention through its natural expressiveness and lively immediacy.

    Building on the very successful previous models, the FUOCO delivers the accumulated know-how like a musical tempest – ’con fuoco’ to use the musical expression behind its name. With it comes the ’plug and play’ guarantee of total satisfaction as part of an Ensemble system – yet its neutral, say very natural and balanced character also makes it an ideal partner for many other high quality combinations. It is known to drive many speakers to new, unexpected levels of peformance.

    The FUOCO continues to demonstrate how successful a marriage of tubes and bipolar transistors can bring out the best of both technologies. While the tubes in the input stage demonstrate their superior way in handling the harmonic textures and timbres as well as the complex dynamics of music without running into problems of saturation, the bipolar transistors in the output stage provide low distortion and have the necessary low impedance to control the speakers, especially in the lower registers. The way the ECC81 (12AT7) type double-triode tubes are used, they need no adjustments or periodic controls. Apart from their friendly glow and warmth, for the user they function like solid-state devices.

    A lot of thought and attention has been given to every single constructional detail. The appreciative eye will notice the quality of the metal work, the shape and fine finish of the knobs, as well as realize that the RCA sockets and binding posts are all Ensemble designs. With the signal-conducting part made of copper plus direct thick gold-plating (as against the usual nickel plating with a rush of shiny gold) they are in a class of their own, not only in terms of the quality of the contacts but also in terms of their electrical conductivity being three times higher than brass. A more inquisitive inspection of the construction will further reveal that the transformer, the inputs with the main board (housing the sensitive electronics) as well as the rear wall with the speaker outputs and power input are all decoupled, ie constructionally isolated from the main chassis. This is part of the underlying MICROSORB™ concept, developed by Ensemble to embrace all aspects of resonance control in a given design.

    The same no-compromise design can be found on all other levels. So the signal does not pass through but is just piloted by the user-operated source and monitor switches and balance control. Connections between mother- and powerboard are spring-loaded laboratory grade types.

    Every single component has been painstakingly selected both for its sonic qualities and reliability. Thus only the finest selected and matched tubes of the ECC81 family, ie NOS from the golden era of German and British tube manufacture are used. They are fitted with Ensemble TUBESOX™ tube dampers to protect them from microphony.

    In the preparation for this new generation of amplifiers it became clear that in order to eliminate any potentially weak point it was necessary to design a new kind of Noval tube socket. The FUOCO and EVIVO amplifiers are the first to use Swiss precision-made, spring-loaded, gold-plated copper contacts for each of the nine pins. Inserting a tube into these Ensemble NOVALINO™ sockets, contact is made with a snap.

    The SONDORO series sees an all-out effort to have all the critical passive components made to Ensemble state-of-the-art specifications. Among these are the Golden Gate™ reservoir capacitors, various types of PROCAP™ polypropylene capacitors and low-noise amagnetic precision resistors.

    As a further element in the sophisticated concept of maintaining the quality of the signal, the FUOCO amplifier uses a specially developed audio-grade isolation transformer (which also fulfills medical equipment stan- dards). Tying in with this is the protective internal wiring that makes use of the shielded Ensemble DYNALINK™ and MEGALINK™ cables.

    Operational reliability has also been given the same high priority. The two most apparent safety elements are the switch-on mute (~50 seconds) and the automatic switch-off function, which is activated when the amplifier is put into overload by excessive volume, or when it sees a short or DC. As soon as the situation is cleared, the amplifier goes back into play mode.
    Further protection is afforded by ’superfast’ speaker output fuses (accessible from the outside), servo- operated biasing of the output stage (avoiding overheating), auto-resetting thermal fuses in the transformer, fuses for the power supply as well as double mains fuses in the electrical input socket (accessible from outside).

    And finally, when using an Ensemble interconnect with its ALLINO™ RCA connectors a ground to ground connection will first be made. Thumps or other potentially destructive signals for the speakers therefore cannot happen with Ensemble electronics and cables.

    The FUOCO accepts 5 line sources and has a monitor loop. Each of these inputs is relay-controlled. The monitor function – which also acts as a mute in the absence of a signal – can be addressed either by the remote control or manually.

    A switch allows the balance control to be taken out of function (resulting in a signal output gain of 2 dB). Volume control is by means of a motorized potentiometer. Preference has been given to this solution, as it allows control by hand as well as by remote and has the tactile, visual quality along with it. In powering up the FUOCO, the volume control – as if by magic hand – will go back from whatever position to zero and then after a few seconds set itself to a low level volume. By that time the start-up mute has been released – a musical journey of never-ending discoveries has begun.

    Made in Switzerland to the highest standards of precision and quality, the FUOCO has everything to become the long-term centerpiece of a serious music system.

    Just as much as the FUOCO will give that special kind of long-term satisfaction, all other Ensemble components will do the same, as they are made with the same considerate care and in the same design approach. Ensemble considers them all to be musical instruments.


    • Audio-grade isolation (mains) transformer

    • Advanced hybrid circuit design (tubes-transistors)

    • Input (voltage gain) stage with select-grade, matched tubes of the ECC81 (12AT7) family

    • Ensemble NOVALINO™ tube sockets

    • Ensemble TUBESOX™ tube dampers

    • Bipolar power transistors

    • 5 relay-controlled inputs

    • 1 monitor loop, with manual and remote control

    • Ensemble SYNERGIA™ RCA jacks

    • Remote-controlled and manual volume adjustment

    • Ensemble PROCAP™ capacitors, Golden Gate™ reservoir capacitors

    • MICROSORB™ resonance control system

    • Sensitive electronics, signal and electrical inputs, speaker outputs,
      as well as transformer decoupled from chassis

    • 8-tier operational safety system

    • Auto-resetting mute to protect speakers

    • All-copper Ensemble SYNERGIA™ 5-way binding posts (see below)

    • Voltage selector for 100 V, 115-120 V, and 220-240 V (50-60 Hz) mains


    Power nominal

    100 W / 8 ohm 150 W / 4 ohm per channel

    Input sensitivity

    0.36 V (150 W / 4 ohm)

    Input impedance

    45 kohm


    99 dB (full power 4 ohm to noise floor)


    0.2 % (1 W / 4 ohm / 1 kHz)

    Negative feedback

    20 dB

    Input tubes

    Selected, matched ECC 81 (12AT7)

    Voltage selector

    100 V, 115 V, and 230 V (50/60 Hz) mains

    Mains fuses

    2 x 3.15 A T / 250 V (slow-blow) 220-240 V mains
    2 x 5 A T / 250 V (slow-blow) 100-120 V mains

    Power supply fuses

    4 x 4 A T / 250 V (slow-blow)

    Speaker output fuses

    2 x 6.3 A FF / 250 V (super-fast)

    Speaker outputs

    Ensemble SYNERGIA binding posts, accepting
    6 mm bananas (100 ampere-rated)
    4 mm bananas
    8 mm spades
    10mm²- AWG7 nude cable

    Dimensions (wdh)

    395 x 315 x 135 mm (15.5″ x 12.4″ x 5.3″) (wdh)
    550 x 430 x 350 mm (21.6″ x 17″ x 13.8″) boxed


    15.5 kg (34 lbs) net, 19 kg (42 lbs) shipping weight


    Remote control handset
    TUBESOX™ tube dampers
    FLEXO™ shielded power cord (1.5 m)
    optional ZORBO™ equipment platform


    2 years on parts (tubes 6 months)
    with the exception of all cases of failure
    due to mishandling, unauthorized modification,or overvoltage.