Musical Fidelity M8xi Instruction Manual

M8xi Integrated Amplier

Super Integrated Amplier

Design Background

In 1990, Musical Fidelity made

the rst ever Super Integra­ted amplier: the A 1000. lt

received a rapturous welco­me and, even today, second
hand, is selling at high prices.

The A1000 was the rst of a
long line of Super Integrated
Ampliers from Musical Fideli­ty. Its children: the NuVista M3,
Tri Vista 300, kW500, M6/500i,
NuVista 800 and NuVista 600

all were equally enthusiasti­cally welcomed to the audio­phile world ..
The M8xi is the latest and the

best of the breed.

General Description

The M8xi is a separate pre­amp with two monobloc po­wer amps sharing a common
chassis. Each has its own heat

sink and separate transforrner.

Genuinely dual mono.
The preamp has its own se­parate power supply and is
mounted close to the input

sockets.
Consequently, PCB tracks are

very short. This elegant idea
ensures that both channels
signals are ultra low impedan-

ce from the instant they get
into the amplier. This is a sig­nicant detail.

Each channel has twelve big
bipolar transistors - 200 amps
peak to peak is easily availa­ble.

The metalwork is high quality.
The front panel is a custom
made ne line extrusion of mil-

spec aluminium. The custom
made heat sinks have out­standing dissipation charac-

teristic and nish.

The M8xi construction has the

feeling of solidity and quality.

MUSICAL FIDELITY

www.musicaldelity.com

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Technical data and price changes reserved.

New Circuitry

Over the last 5 years our power amp circuitry has reached a high state of development. In our
never ending quest for improving performance and customer value we have been looking for
ways to improve our designs. One of the prime directives was to keep the low feedback con­guration unchanged .. continue with low feedback! The problern was how to improve efcien­cy and performance without affecting the sound quality.
If I say so myself, I think we have come up with a brilliant solution. Our new M8xi power amp

design gives higher power, lower distortion and better sound quality. Incredible but true.

The output stage efciency has been increased thus yielding about 10% more power for similar
power supply voltage. More importantly the whole driver stage is pure Class A. We believe that
this innovative approach has a substantial effect on the sound quality.

The sound stage appears wider whilst the micro and macro dynamics have more impact. This

effect is particularly noticeable on well recorded piano. I am sure you all know the piano is a

percussive instrument but in truth this is rarely audible on most Hi Fi systems.

Using an M8xi a piano‘s percussive nature becomes instantly obviously and jumps out of the
loudspeaker. lt is a surprising and satisfying improvement to the sound quality.
Vocals have more subtly, detail and presence. Large scale music has a depth, width and incre-

dibly dynamic presentation.

All in all the M8xi is a consummate all-rounder. Mostly it sounds like a small Class A amplier with

huge power.

Technical Performance

The M8xi delivers 550 + 550wpc into 8 ohms. It is extremely stable and very linear.
The distortion is low too; lower than 0.005% in the audible frequency range of 20 Hz to 20 kHz.
The M8xi has remarkable linearity and consistency. lt is unconditionally stable and will drive any
loudspeaker in existence easily with ample power reserve.

Our Approach to Technical Measurements

In our view an amplier should be completely neutral. lt is ‚a straight wire with gain‘. Easy to
say but hard and complex to do. We want to stress that we do not believe that the technical
performance is an end in itself. lt is a method of validating the total amplier system concept.
The aim of our circuit/PCB designs is to have low feedback and achieve complete neutrality,
transparency and great technical performance. The proof that we are on the right track is the
technical performance. We think that technical performance cannot be summed up by the
distortion at 1 kHz. Our view is that an amplier has to be able to satisfy a wide range of techni­cal requirements before it can be neutral.

Linearity

Almost all loudspeakers have complex impedance and Ioading curves. An amplier must be
able to maintain its voltage virtually, regardless of loading. If an amplier cannot maintain its
voltage across the spectrum, then the ultimate frequency response and distortion will be non

linear. This is not neutrality.

MUSICAL FIDELITY

www.musicaldelity.com

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Technical data and price changes reserved.