Overview
After eleven years, and after extensive technical development projects at Octave, it was time to further adapt the MRE 220 mono power amplifiers – the rock in the surf – to the higher demands of modern loudspeakers.
Long listening sessions led to the solution of an adjustable damping factor. The new MRE 220 SE damping factor can now be flexibly adjusted to ideally suit the respective speaker – resulting in rock solid reproduction quality with virtually any loudspeaker.
Technology
Today’s modern loudspeaker designs feature high-resolution and fidelity beyond what was achieved in the past. This, combined with the triumph of high-resolution digital formats and an extraordinary leap in vinyl playback fidelity, has led to an unprecedented quality of music playback in modern high-end systems. Despite all efforts, developing a power amplifier that harmonizes perfectly with all loudspeakers is – as experience shows – still very difficult, if nearly impossible. The requirements of the loudspeaker are too different in terms of power requirements, bandwidth and its performance, which is affected by the damping factor (and/or negative feedback) of the power amplifier.
In listening tests with many different loudspeakers during the MRE 220 SE design process, an important new tool emerged that ensures more optimal matching between our amplifier and a wider range of loudspeaker designs: an option to vary negative feedback that impacts the attenuation factor. Through use of chassis-mounted switches, the listener can choose between two damping factor settings, “LOW” or “HIGH”, along with separate settings for negative feedback. This is a completely new approach to the problem of a tube power amplifier that has to cope as well as possible with all the loudspeakers available on the market. With this unique adjustment option, the interaction of the MRE 220 SE with nearly any loudspeaker can be optimized almost perfectly. The result of this flexibility speaks for itself: an incredibly clear, spacious soundstage with a perfectly resolved and entrancing midrange that is free of any impurities, along with a silky, beautiful tonal balance.
Upgrade Options
Super Black Box ($3,500)
The Super Black Box is a passive power supply extension designed for all Octave integrated and power amplifiers. Due to the massively increased storage capacity of the power supply, the pulse power of the power amplifiers is significantly increased. What is also very important is the increased independence from the electrical load – the loudspeaker. A big sonic benefit, not just for sophisticated speakers.
Black Box ($1,500)
The Black Box is a smaller version of the Super Black Box with the same concept. It contains a circuit with electrolytic capacitors that increases the internal power supply of the amplifier and stabilizes it against mains fluctuations. Low-frequency network interference is perfectly suppressed. The Black Box has its own housing and is permanently connected to the amplifier using a special high-current connector.
KT150 Upgrade Tubes, Set of 4 ($800)
The MRE 220 SE is fitted with a set of four KT88 S4-A carbon tubes as standard. For speakers that demand additional power, the KT150 upgrade is highly recommended.
