Musical Fidelity NU-VISTA 300 User manual

Nu-VISTA 300 Power Amplifier Instructions for Use. Page 1of 12
INSTRUCTIONS FOR USE
Thank you for purchasing the Musical Fidelity special limited
edition, Nu-Vista 300 Power Amplifier.
Your unit is one of only 500 to be made and has been designed for
ultra high definition and performance. Aesthetically and electronically
the Nu-Vista 300 matches perfectly with the Nu-Vista preamplifier.
This Nu-Vista 300 uses the very high quality 6CW4 Nuvistor triode
valve, the same as in the Nu-Vista preamplifier.
Together, the Nu-Vista preamplier and power amplifier form one of
the finest hi-fi systems available.
For the best results Nu-Vista interconnects and loudspeaker cables
should be used.
If you have any questions about anything in your
audio system, please consult your dealer who is there to help and
advise you.
POWER AMPLIFIER

Nu-VISTA 300 Power Amplifier Instructions for Use. Page 2of 12
SAFETY INFORMATION
IMPORTANT!
This unit is supplied in the UK with a mains lead fitted with a moulded 13 amp plug.
If, for any reason, you need to cut off this plug, please observe the following safety precautions.
Please dispose of the cut-off plug safely. It must not be plugged into a mains power supply.
The wires in the mains lead supplied with this appliance are coloured in accordance
with the following code:
Green and yellow..............Earth
Blue...............................Neutral
Brown................................Live
WARNING - This appliance must be earthed
As the colours of the wires of the mains lead of this appliance may not correspond with the
coloured markings identifying the terminals in your plug, proceed as follows:
The wire which is coloured green-and-yellow must be connected to the terminal in the plug
which is marked with the letter E or coloured green or green-and-yellow, or by the earth
symbol.
The wire which is coloured brown must be connected to the terminal which is marked with the
letter L or coloured red.
The wire which is coloured blue must be connected to the terminal which is marked with the
letter N or coloured black.
If connecting to a BS1363 plug, a 13 amp fuse must be used.
WARNING - Radio Frequency Interference (RFI)
This hi-fi product has been tested to ensure that its operation will not be adversely affected by
normal background levels of RFI. It is possible that if this product is subjected to abnormally
high levels of RFI the unit may be susceptible and not perform as expected. In the unlikely
event of this happening on a regular basis, please contact Musical Fidelity's service department.
The unit has also been tested to ensure that it does not radiate excessive levels of RFI that could
affect other pieces of electronic or electrical equipment.
The electronics in modern hi-fi equipment is complex and hence may be damaged by lightning.
It is possible that during electrical storms the operation of some equipment may be adversely
affected. For complete protection of your hi-fi system during such storms, mains plugs and aer-
ial leads should be disconnected.
Always ensure that when disconnecting and reconnecting your hi-fi equipment the mains sup-
ply is switched off.

Nu-VISTA 300 Power Amplifier Instructions for Use. Page 3of 12
SAFETY INFORMATION
IMPORTANT!
ALL CONNECTIONS SHOULD BE MADE WITH THE POWER OFF.
ENSURE THE MAINS LEAD IS NOT CONNECTED TO THE MAINS
SUPPLY AND THE UNIT SWITCHED OFF BEFORE MAKING ANY
CONNECTIONS
THE NU-VISTA 300 IS A VERY POWERFUL AMPLIFIER AND IS
DESIGNED TO SUPPLY HIGH VOLTAGES AND HIGH CURRENTS
THROUGH THE LOUDSPEAKER TERMINALS. THEREFORE TO AVOID
ANY POSSIBILITY OF AN ELECTRIC SHOCK DO NOT TOUCH THE
SPEAKER TERMINALS WHEN THE UNIT IS BEING USED.

INTRODUCTION
Nu-Vista 300 Power Amp "breaks the rules" to offer ground-breaking per-
formance
The Nu-Vista 300 power amp is the heir apparent to the great tradition of British
electrical and mechanical engineering
excellence. It is also proof positive that
those who understand the rules of amplifier
design best, can break them with the best
results.
Designed to complement the Nu-Vista preamplifier, which notched up new
preamp standards, the Nu-Vista 300 power
amp sets new standards for power ampli-
fiers. This is achieved in several ways:
through the use of a sophisticated, hybrid
nuvistor circuit, which can produce huge
peak currents and massive power levels. By
using a unique choke-regulated power sup-
ply. And by flying in the face of convention
in the physical layout of such a massive
power amp.
The results speak for themselves. The Nu-Vista 300 top end is extended and
beautifully clear, the midrange is pure and
as transparent as the finest optical crystal
and the bottom end extends down virtually
to infinity. Resolution and definition have
integrity to electron -microscope-level
detail. And for all practical purposes, the
Nu-Vista 300 power amp has no dynamic
range limits.
The Nu-Vista 300 is a big power amp with unlimited headroom, massive
power, high current, low distortion, high
stability margins and obsessive attention to
magnetic flux. This is not an amplifier for
the timid.
Design objectives of the Nu-Vista 300 power amp
1. Sound quality
2. Low distortion with low feedback
3. High power and high current
4. Stability margins
5. Consistency
6. Build quality and aesthetics
1) Sound quality
The Nu-Vista 300 power amp sets new standards for audio electronics because
it is able to transfer the purity and clarity of
the Nu-Vista preamp to the loudspeakers.
To achieve this, the Nu-Vista 300 has very
wide bandwidth coupled with low distortion
and a huge dynamic range.
Due, in part, to its very high input imped- ance and sophisticated circuit, the top
end of the Nu-Vista 300 is remarkably lucid
and extended. There is no grain, no distor-
tion, no harshness of any sort - and no
power limit. The Nu-Vista 300 simply
delivers to the loudspeakers an amplified
version of exactly what is fed into it.
The midrange is simply pure, with no colouration and no grain. The effect is
like looking through the purest form of opti-
cal crystal. You know it's there, but it's vir-
tually invisible. Similarly, with the Nu-
Vista 300, there are no intrusions.
The bottom end is profoundly extended. It is also extremely fast, with not a hint
of overhang. It has speed, slam and attack.
It is all but impossible to clip or overdrive
the Nu-Vista 300 in the bottom end. The
real question is: can your loudspeakers han-
dle an amplifier which, in practice, has no
dynamic limits.
Nu-VISTA 300 Power Amplifier Instructions for Use. Page 4of 12

INTRODUCTION
In music, everything depends upon the bass line. It's the same in hi-fi. Given the
proper foundation, other elements snap into
focus. The imaging of the Nu-Vista 300 is
positively tactile.
2) Low distortion with low feedback
With an amplifier of this power and dynamic range, it is absolutely criti-
cal that there be no audible distortion. Even
in amplifiers which measure well, distortion
may creep into the listening experience.
Therefore, Musical Fidelity put a vast
amount of effort into ensuring that the meas-
ured and real life distortion are vanishingly
low. Typically, the Nu-Vista 300 has less
and .01% distortion from 20Hz-20KHz
when delivering high power levels into a
wide variety of loads.
Even at ultrasonic frequencies up to 100KHz, the distortion remains below
1%.
Low frequency distortion is similarly negligible. The Nu-Vista 300's sophis-
ticated, three stage, magnetic feedback,
choke regulated power supply (unique in the
world, as far as we know) allows the power
amp to deliver amazingly deep bass with no
overhang and with extraordinary slam,
speed and presence. Talk about feeling bass
dynamics in your gut - this is it.
3) High power and high current
Massive power and current delivery are a must for a power amp to deliver
proper dynamic range with an average sen-
sitivity loudspeaker. If you want realistic
dynamic range, the minimum power
requirement with a loudspeaker of about
89dB sensitivity is 200 watts per channel.
The Nu-Vista 300 will deliver 300 watts into 8 Ohms, 600 watts into 4 Ohms,
and about 1000 watts into 2 Ohms.
The Nu-Vista 300 can deliver 80 amps peaks. As far as we are aware, there is
not a loudspeaker in existence which can
cause the Nu-Vista even the slightest prob-
lem. The Nu-Vista 300 can sink any load
presented to it, and still continue to deliver
almost limitless dynamic range.
Physical layout is critical to the perform- ance of a power amp capable of such
large voltage and current swings. The con-
sensus is that mono bloc design is the best,
but we disagree. When an amplifier is
delivering high currents or voltages, these
can easily be picked up by the circuit, inter-
connect cables, components or even by the
amplifier's casework. These magnetic flux
surges will affect the sonic performance of
the amplifier. Also, the zero volts of two
mono bloc amplifiers will be marginally dif-
ferent. This may affect imaging and other
subtle areas of the listening experience.
The solution developed by Musical Fidelity is to build two completely
mono amplifiers in the same box, keeping
each channel's power supply completely
separate.
The Nu-Vista 300 has three transformers: one for each power amp and one for the
control circuits. As a result, there is no
magnetic interference from, the transform-
ers to the circuitry, and the zero volt poten-
tial of both power amps is identical.
We found that this solution offers sig- nificant audible benefits. It isn't con-
ventional, it isn't politically correct and it
isn't what every reviewer has been told for
the past 20 years, but we think it's the right
solution. The only thing that matters in the
end is how an amplifier sounds: the Nu-
Vista 300 does not disappoint in any area.
Nu-VISTA 300 Power Amplifier Instructions for Use. Page 5of 12

INTRODUCTION
4) Stability margins
The Nu-Vista 300 can drive any loud- speaker with any cable to any required
acoustic level within the power handling
limits of the loudspeaker. It's that simple:
the Nu-Vista 300 will do anything you ask
of it.
5) Consistency
Because of the Nu-Vista's uncoloured sound, low distortion, stability margins
and remarkable power and current delivery,
it will produce consistent performance in
any system.
6) Build quality and aesthetics
The Nu-Vista 300 build quality is superb. Its custom-made, die-cast heat
sinks weigh 15.5kg and are, we believe, the
largest of their type ever to be used in an
audio amplifier. They have excellent ther-
mal properties, are anti-resonant and give a
unique visual identity to the Nu-Vista 300.
The front panels are hewn form mil-spec aluminium billet and then machined
and finished to the highest tolerance.
The custom-made extrusions for the power supply are designed to be anti-
resonant, as well as good-looking.
The complete casework of the Nu-Vista has a solid feel that reflects the excel-
lent materials and workmanship that go
into its making.
The massive, gold-plated solid brass, bi- wiring loudspeaker terminals allow the
use of seriously heavy-duty cable, and are
also easy to use.
Musical Fidelity designed the Nu-Vista 300 power amp from the ground up,
rather than try to force it into the mould of
generally-accepted ideas or concepts dictat-
ed by industry "heavy-weights".
The Nu-Vista 300 power amp costs a great deal, but we believe it offers
excellent value. We are not aware of
another power amp in the world which
offers a matching combination of sound
quality, power, flexibility, built quality and
collector status as the Nu-Vista 300.
Nu-VISTA 300 Power Amplifier Instructions for Use. Page 6of 12

Nu-VISTA 300 Power Amplifier Instructions for Use. Page 7of 12
USER INFORMATION
INSTALLATION PRECAUTIONS and USER INFORMATION
Your new Nu-Vista 300 is designed and built to provide trouble-free performance but as with all
electronic devices it is necessary to observe a few precautions.
Heed all warnings on the back of the unit.
Only connect the Nu-Vista power supply to a mains outlet of the voltage marked
on the back of the unit.
Position the power supply leads speaker leads and signal interconnects where
they are not likely to walked on or trapped by items placed on them.
Do not use near water.
Do not place the units near direct heat sources such as radiators or other
equipment that producers heat.
Do not place the units where they can be subjected to direct sun light.
Do not remove any covers or try to gain access to the inside. The warranty is
invalid if the units have been tampered with. There are no user adjustments with-
in. Refer all service work to an authorised Musical Fidelity agent
Dust regularly with a soft duster or soft brush but be careful when using cleaning or
polishing agents -they may harm the surface finish.

Nu-VISTA 300 Power Amplifier Instructions for Use. Page 8of 12
1LH PROTECT LED
2LH STANDBY LED 4RH PROTECT LED 5RH STANDBY LED
3OPERATE LED
1 2 3 4 5
1234
56789
1RIGHTSPEAKER output terminals
2RIGHTSPEAKER output terminals
3LEFTSPEAKER output terminals
4LEFTSPEAKER output terminals
5RIGHT PSU INPUT socket
6RIGHT AUDIO INPUT RCA socket
7CONTROLPSU INPUT socket
8LEFT PSU INPUT socket
9LEFT AUDIO INPUT RCA socket
Nu-Vista 300 Power Amplifier Front Panel
Nu-Vista 300 Power Amplifier Back Panel

Nu-VISTA 300 Power Amplifier Instructions for Use. Page 9of 12
1LH PSU LED
2LH CONTROL LED 4RH PSU LED 5RH CONTROL LED
3ON/OFF Mains switch
1 2 3 4 5
4 5 6 7
1 2 3
1RIGHT PSU OUTPUT socket
2CONTROL PSU OUTPUT socket
3LEFT PSU OUTPUT socket
4RIGHT PSU FUSE
5CONTROLPSU FUSE
6LEFT PSU FUSE
7MAINS IEC INLET
Nu-Vista 300 PSU Front Panel
Nu-Vista 300 PSU Back Panel

CONNECTIONS
LOUDSPEAKERS
To get a realistic soundstage and full
dynamic range from your Nu-Vista 300,
use it with loudspeakers of a reasonable
efficiency and high power handling. We
reccomend power handling of at least
200W. An average rating for a loudspeaker
these days is about 88dB. This should
mean that for an input of 1 watt, measured
at 1 metre distance, the sound pressure out-
put will be 88dB. This is the minimum
efficiency that we recommend you should
use.
CONNECTIONS
All connections should be made with the
power OFF, i.e. before the mains lead is
plugged in and the unit switched on.
PSU to Amplifier Connections
The Nu-Vista 300 is supplied with three
power supply connecting leads.
Two of the leads are identical.
a) One of these leads connects the
right PSU output to the right PSU input on
the amplifier.
b) The other one connects the left PSU
output to the left PSU input on the
amplifier.
Push the connectors into the sockets and
twist until they click in to place.
c) The third lead supplied is to con-
nect the control PSU output to the control
PSU input on the main amplifier. Push the
connectors into the sockets.
The Nu-Vista 300 can be used with a pre-
amplifier or any line level source which
has a volume control. We highly recom-
mend the matching Nu-Vista preamplifier.
How to connect your Nu-Vista 300 for
Normal Stereo use.
Connect the Left and Right outputs from
your pre-amp or other line level source to
the phono inputs on the back panel marked
as Left and Right Audio Inputs. For the
best results we recommend that you use
Musical Fidelity Nu-Vista interconnect
cables for this connection.
Connect your loudspeakers to the loud-
speaker terminals situated on the back
panel marked as Left and Right
Loudspeaker Outputs. We recommend that
you use Musical Fidelity Nu-Vista O.C.C
speaker cables for this connection.
Once these connections are made, plug in
the IEC type mains lead supplied with the
unit.
RECHECK ALL THE CONNECTIONS
BEFORE SWITCHING ON.
DO NOT TOUCH THE SPEAKER TER-
MINALS WHEN THE UNIT IS OPERAT-
ING.
The NU-VISTA 300 is a very powerful
amplifier and is designed to supply high
voltages and high current through the loud-
speaker terminal
Nu-VISTA 300 Power Amplifier Instructions for Use. Page 10 of 12

OPERATION
BEFORE YOU SWITCH ON
You should make all connections to the Nu-
Vista 300 before switching on.
Follow this routine before you listen for the
first time, and each time you change any
connections.
1Check all the inputs and outputs to the
Nu-Vista 300.
2Then check again.
3Turn the volume control on the pre-
amplifier to nil.
4Now you can switch on the power.
5The NU-VISTA 300 has a switch on
delay circuit. This allows the
Nuvistors to warm up and stabilize
before the amplifier is connected to
the loudspeakers.
6When the mains switch is turned on,
all the LEDs on the front of the PSU
unit should light. If any one of the
LEDs do not light, turn off the power
and recheck all the connections.
7On the main amplifier unit the yellow
LH STANDBY and yellow RH
STANDBY LEDs will light.
8After 15 seconds or so the yellow
STANDBY LEDs will go out and the
green OPERATE LED will light.
The amplifier is now ready for use.
WARNING - Heat
When in use the Nu-Vista 300 gives off
heat from its casework.
Never put anything on top of your Nu-
Vista 300.
Always ensure that the unit has adequate
ventilation.
WARNING - PROTECTION CIRCUIT
The NU-VISTA 300 is equipped with a
sophisticated protection circuit. If this cir-
cuit has been activated for any reason,
either of the red PROTECTION LEDs will
light, indicating which channel has been
protected. The amplifier will immediately
go into standby mode. The yellow
STANDBY LEDs will light and the green
OPERATE LED will go out.
After 15 seconds or so, the amplifier will
return to operate mode. If the problem that
caused the protection to operate has been
cleared then operation will resume.
If the condition that caused the protection
circuit to activate is still present, the red
PROTECT LED will light again and the
same sequence will be repeated until the
fault is cleared.
Listed below are possible reasons for the
protection circuit to activate.
a) Amplifier is being driven into clip-
ping, - reduce volume control
b) Short circuit on speaker terminals -
check that all speakers wires are ter-
minated correctly. no loose strands of
wire. If bi-wiring check this has
been done correctly.
Nu-VISTA 300 Power Amplifier Instructions for Use. Page 11 of 12

POWER OUTPUT 300 watts per channel into 8 Ohms
600 watts per channel into 4 Ohms
1000 watts per channel into 2 Ohms
THD < 0.005% at 1KHz
< 0.008% 20Hz - 20KHz unweighted
< 0.003% 20Hz - 20KHz “A” weighted
FREQUENCY RESPONSE 10Hz - 56KHz +1dB
INPUT SENSITIVITY 1.5V (for full output)
INPUT IMPEDANCE 100KOhm
S/N RATIO > 88dB ‘A’ weighted (Ref 1W)
> 113dB ‘A’ weighted (Ref 300W)
POWER CONSUMPTION 1.2KW Max
DIMENSIONS Amplifier 330 x 170 x 490 (W x H x D)
Power supply 330 x 170 x 490 (W x H x D)
Height includes feet
Depth includes terminals
Nu-VISTA 300 Power Amplifier Instructions for Use. Page 12 of 12
Power Amplifier
Musical Fidelity reserves the right to make improvements which may result in specification or feature changes without notice.
SPECIFICATIONS