MUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates User Manual

June 9, 2024
MUSICAL FIDELITY

MUSICAL FIDELITY Nu-Vista PAS High-End Hi-Fi Separates

MUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates-
product

Product Information

The Musical Fidelity Nu-Vista PAS is an audio system that provides outstanding musical reproduction. It is built based on the Nu-Vista 800 circuit and is fully balanced. The system comes with its own dedicated external power supply, the Nu-Vista PAS PSU, which is built with inbuilt mains and output filtering to achieve better noise performance. The Nu-Vista PAS and its PSU use Nuvistor tubes which are known for their high performance and low noise characteristics. The system is designed to provide many years of exceptional musical reproduction.

Product Usage Instructions

Cleaning: Dust the unit regularly with a soft duster or soft brush. Avoid using cleaning or polishing agents as they may harm the surface finish.

Installation:

  • Position the Nu-Vista PAS and its PSU on a stable, horizontal surface where there is no risk of it being knocked.
  • Make sure ALL units involved are switched off and unplugged from the main supply before making or removing any connections.
  • Place the Nu-Vista PAS PSU next to the PAS unit itself, with as much space between them, so that all power cables can be connected comfortably and there is no extra strain on the cables.

Safety Information:

  • The unit should not be plugged into a main outlet.
  • Any modifications to the product not expressly approved by Musical Fidelity could void the user’s authority to operate this equipment.
  • The wires in the main lead supplied with this appliance are coloured in accordance with the following code: Green and yellow (Earth), Blue (Neutral), and Brown (Live).

If there are any questions about the audio system, please consult the dealer, who is there to help and advise.

Instructions for use

Thank you for purchasing the Musical Fidelity Nu-Vista PAS.
Based on our excellent Nu-Vista 800 circuit we decided to go all out “fully balanced” on the Nu-Vista range.

The Nu-Vista PAS features the tried and tested Nu-Vista stage featuring 6S51N visitors in a discrete class A amplifier buffer. This is followed by a balanced configuration circuit and balanced input high power, low distortion output amplifier stage. The power stage has 5 pairs of high-power thermally compensated output devices for reliable and stable operation. Based on the Titan 1000W stage, it has separate capacitors for bulk supply, and one each for output devices considerably reducing output impedance and improving dynamics. Chokes are added for further improved supply ripple and pulse current spike reduction. Bias is set for over 5W of initial class A operation thereafter the stage slides into class B operation at a point where the now much lower discontinuity is easier dealt with than “standard” crossover distortion.

The Nu-Vista PAS comes with its own dedicated external power supply, the Nu- Vista PAS PSU. To achieve better noise performance, we removed the AC mains power supply from the main unit and built it into another matching box. In this box, we took advantage the extra space to set up inbuilt mains and output filtering. This quietens up the supplies and results in almost no mains-borne artifacts getting into the sensitive audio circuitry.
Used properly and carefully, it should give many years of outstanding musical reproduction.

Dust regularly with a soft duster or soft brush, but be careful when using cleaning or polishing agents – they may harm the surface finish.
The new Nu-Vista PAS and its PSU were a continued labor of love for Musical Fidelity. We are passionate about what we do and passionate about Nuvistor tubes as we have always been. We hope that you derive as much pleasure from listening to the Nu-Vista PAS as we had created it.
If there are any questions about the audio system, please consult the dealer, who is there to help and advise.

CUTAWAY VIEWS

Showing Cylindrical Electrodes and Tripod-Like Supports

MUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates-
fig-1

SAFETY INFORMATION

IMPORTANT! (U.K. only)
This unit is supplied in the U.K. with mains lead fitted with a moulded 16 amp plug. If, for any reason, it is necessary to remove the plug, please remove the fuse holder and dispose of the plug safely, out of reach of children.

It must not be plugged into a main outlet.
The wires in the mains lead supplied with this appliance are coloured in accordance with the following code:

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 the 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:
ANY MODIFICATIONS TO THIS PRODUCT NOT EXPRESSLY APPROVED BY MUSICAL FIDELITY WHO IS THE PARTY RESPONSIBLE FOR STANDARDS COMPLIANCE COULD VOID THE USER’S AUTHORITY TO OPERATE THIS EQUIPMENT.

GENERAL ADVICE

Installation, Precautions & User Information

This new Nu-Vista PAS 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 shown on the back of the product.

  • Only connect the Nu-Vista PAS to a mains outlet having the same voltage as marked at the back of the unit.

  • Always ensure that when disconnecting and reconnecting your audio equipment the mains supply is switched off.

  • Position the mains lead and signal interconnects where they are not likely to be walked on or trapped by items placed on them.

  • Do not use near water, or place water-filled containers on the Nu-Vista PAS & PAS PSU, for example, a flower vase or potted plants. If water does spill inside, immediately pull out the mains plug from the wall socket and inform your dealer, who should then check the unit before further use. Entry of liquid into the Nu-Vista PAS and PAS PSU is dangerous, and may cause electric shock or fire hazard.

  • Do not place the unit near direct heat sources such as radiators, direct sunlight or other equipment.

  • Do not remove any covers or try to gain access to the inside. There are no internal adjustments or fuses you can replace yourself. Refer all service work to an authorised Musical Fidelity agent.
    * Note: Unauthorised opening of the equipment will invalidate any warranty claim.

  • Dust regularly with a soft cloth or soft brush but be careful when using cleaning or polishing agents – they may harm the surface finish.

The electronics in modern hi-fi equipment is complex and may, therefore, be adversely affected or damaged by lightning. For protection of the audio system during electrical storms, remove the mains plugs.
If after-sales service is required, to help the dealer identify the Nu-Vista PAS & PAS PSU please quote the serial number located on the rear panel of the unit.

INSTALLATION

Introduction
Congratulations on the purchase of the new Nu-Vista PAS stereo power amplifier. Great attention has been paid to internal layout, isolating each circuit section to prevent possible interaction. The unit features a finely tuned and tweaked Nu-Vista valve design, for smooth sound coupled with low noise and virtually no distortion. The power amplifier consists of two top quality power amplifiers for the absolute best in separation and imaging. Generously rated, they are enough to drive even the most demanding loudspeakers with ease. Low distortion and very quiet they will deliver all music types exactly as the artist originally intended.
The resultant performance achieved by this unit is among the best in the world. It has excellent signal to noise ratio, low distortion, wide bandwidth and dynamic range, with extraordinary resolution and fine detail.

Cleaning
Before cleaning the unit, switch off power at the mains switch and remove the mains plug from the wall socket. Clean the cabinets using a moist cloth. Using solvents, white spirit or thinners is not advised, as they could damage the surface finish.

Setting up
Position the Nu-Vista PAS and its PSU on a stable, horizontal surface where there is no risk of it being knocked. Make sure ALL units involved are switched off and unplugged from mains supply before making or removing any connections. We recommend to place the Nu-Vista PAS PSU next to the PAS unit itself, with as much space between them, so that all power cables can be connected comfortably and there is no extra strain on the cables.

Important note:
During normal operation, the unit dissipates an appreciable quantity of power at all times, and it is important that it is well ventilated. The top and bottom are perforated to allow the smooth flow of heat through the unit. However, the unit must not be enclosed in a cabinet or placed where the ventilation holes are impeded as this could result in excessive heat build-up.
The Nu-Vista PAS must be protected from humidity – if the unit is moved from a cold place to a warm room, leave the unit for an hour or so to allow sufficient time for the moisture to evaporate.

Audio Connections
Inputs: The Nu-Vista PAS has single-ended (RCA) line level and balanced (XLR) line level inputs. Choose the desired input to be used:

Unbalanced RCA Line Level Inputs:
Connect all RCA single-ended sources to relevant analogue inputs (see page 8 for more information). Use good quality fully connected (signal and ground) coaxial phono cables for all RCA signal connections. Take care with positioning all input leads, try to ensure that they are well shielded and kept as far away from mains and speaker leads as possible.

Balanced XLR Line Level Inputs:
Connect source-balanced outputs to the Nu-Vista PAS balanced inputs using good quality XLR balanced leads. Recommended lead wiring is shown on P.8. Note some products simply connect “cold” input pin 3 to the ground. This does no harm to unit but may result in an audible reduction in signal level from this input and a slightly worse signal-to-noise ratio.
Note: in both input cases it is assumed that the driving preamplifier has a VOLUME CONTROL to allow setting of listening level. This is important as the Nu-Vista PAS has no control of its own.

Outputs: The Nu-Vista PAS has a single-ended (RCA) line level and balanced (XLR) line level output. The output sockets allow a loop through of the input signal, for example, to pass on to a recorder, monitor, additional amplifier or active subwoofer.
Speaker Outputs: Connect loudspeakers to the terminals on the back panel marked as LEFT and RIGHT SPEAKER outputs. See “ WIRING ” P.11 for more details.

Mains Power Input on Nu-Vista PAS PSU
Check the Nu-Vista PAS PSU back panel mains switch is set to “OFF”. Connect the supplied mains lead to the 16A IEC socket on the back panel. Connect the other end to a mains power socket. Be sure to leave the mains switch in the “OFF” position.

CONTROL, Nuvistor PRE and PA Interconnects from Nu-Vista PAS PSU to Nu- Vista PAS amplifier unit

Connect the 4-pin XLR cable between the CONTROL output on the Nu-Vista PAS PSU and the CONTROL input on the Nu-Vista PAS amplifier.
Connect both 5-pin XLR cables between the Nuvistor PRE outputs on the Nu-Vista PAS PSU and the Nuvistor PRE inputs on the Nu-Vista PAS amplifier. This is powering the Nuvistor stages.

Connect both “Neutrik” cables between the PA outputs on the Nu-Vista PAS PSU and the PA inputs on the Nu-Vista PAS amplifier. This is powering the power amplifier stages.
Important notes:

  • Only switch the Nu-Vista PAS PSU on once ALL connections are made.
  • Only connect or disconnect power cables when the ON/OFF switch on the Nu-Vista PAS PSU is set to OFF!
  • If the Nuvistor PRE power cables are wrongly or not connected, the Nu-Vista PAS display will show “Output DC present” and mute the unit. Turn the Nu-Vista PAS and then the PSU off and check the cables again.

Trigger Input and Output
Triggering input and outputs are available to allow the amplifier to be turned on automatically by other equipment or turn on other equipment automatically when the Nu-Vista PAS is turned on. This is a 2-way 3.5mm jack on the back of the unit labelled “TRIGGER”. It requires 5 to 12V (either polarity) to switch the amplifier on.
CAUTION!
Most high-quality speakers will comfortably cope with large power transients. By their nature, these are very quick and will present no thermal problems for a good commercial-quality loudspeaker.
However please note that most loudspeakers are not designed for very high sustained listening levels. The Nu-Vista PAS is a very powerful amplifier and will faithfully deliver what is asked of it. If listening levels are set significantly higher than normal, it is possible that the loudspeakers could get into thermal problems and be damaged. Musical Fidelity will not be responsible for any loss or damage to loudspeakers. Please take care with listening levels, which can damage hearing, and consider the noise suffered by others, such as neighbours.

Additional note-
If bi-amping, please ensure that all speaker shorting links linking treble and bass units are removed. Failure to do so may result in damage to the connected amplifier(s). See loudspeaker instructions for more information.

Mounting optional Spike Feet
The Nu-Vista PAS and PAS PSU can optionally be used with spike feet. We recommend asking a second person to help you lift the amplifier and PSU units for mounting the feet or felt pads. If you want to use the standard mounted feet, you can attach the big felt pads to those feet (remove the small rubber feet first if necessary).
To mount the spike feet, screw the threaded rods into the spike feet so that the allen key side is inside the foot (this way, when you want to remove the foot from the amplifier again, you can unscrew the foot and then unscrew the threaded rod from the amplifier with an allen key, should it be too tight to unscrew by hand). Then screw the feet into the amplifier (remove the small rubber feet first if necessary). Attach the small felt pads to the bottom of the spike feet cups and place these cups under the spike feet.

FACILITIES & CONNECTIONS

MUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates-
fig-4

  1. POWER/STANDBY Button
  2. DISPLAY
  3. SOURCE selector
  4. DISPLAY controlMUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates-fig-5
  5. LOUDSPEAKER OUTPUTS
  6. Nuvistor PRE 5-pin XLR power inputs
  7. XLR BALANCED inputs 1 and 2
  8. RCA SINGLE ENDED inputs 1 and 2
  9. PA “Neutrik” power inputs
  10. TRIGGER input and output
  11. XLR BALANCED line output
  12. RCA SINGLE-ENDED line output
  13. CONTROL 4-pin XLR power input

XLR Balanced input and output lead connections:

(for reference, no XLR signal leads supplied)

Pin functions:

  1. Ground (cable shield)
  2. Normal polarity (“hot” or “+”)
  3. Inverted polarity (“cold” or “-“)

FACILITIES & CONNECTIONS

MUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates-
fig-7

  1. POWER/STANDBY LED’sMUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates-fig-7
  2. Nuvistor PRE 5-pin XLR power outputs
  3. CONTROL 4-pin XLR power output
  4. ON/OFF switch
  5. PA “Neutrik” power outputs
  6. IEC 16A mains socket

OPERATION

Starting
Once all connections are made, switch on the Nu-Vista PAS PSU unit, using the POWER switch on the back panel. The Standby LEDs on both the Nu-Vista PAS and PSU will light up. The Nu-Vista PAS amplifier unit may now be switched fully on using the POWER/STANDBY button on the front of the amplifier. The display will now light up and the POWER LEDs on both units will light up. The LEDs illuminating the Nuvistor valves will light up RED. This means the speaker outputs are muted, and will remain in this state for about 12 seconds, so no sound will be heard from the speakers. Once the delay is up, these LEDs go ORANGE, indicating the unit is ready for use, and any source material selected and playing will be heard through the speakers. For the first 15 mins or so, the Nu-Vista valves are still warming up, and their LEDs stay ORANGE. After approx. 20 mins the valves will have reached full thermal equilibrium and are at their best performance, which is indicated by their LEDs turning BLUE.

Switching Inputs
Switch through the inputs by pressing the INPUT button.

Display Controls

  • Access the display controls by pressing the DISPLAY button once and then:
  • Change the theme between black/white, VU meters on/off by pressing the DISPLAY button.
  • Change the brightness by pressing the POWER (brightness down) and INPUT (brightness up) buttons. Display controls will automatically exit after not pressing any buttons for a few seconds.
  • Pressing and holding the DISPLAY button for a few seconds will turn off the Nuvistor LEDs. This only works after the valves have fully warmed up and their LEDs changed from orange to BLUE.
  • If the valve LEDs are turned on, you can recognize this by a thin blue line that is shown at the top of the display screen.
  • If the valve LEDs are turned off, this thin blue line is not shown.

POWER OFF CAUTION:
The correct power-off procedure should be followed in order to prevent unnecessary power surges on the mains line and to protect the Nu-Vistas. The Nu-Vista PAS amplifier itself should be switched OFF first by the POWER/STANDBY button on its own front panel. Only then turn off the Nu-Vista PAS PSU on its back panel. For day-to-day operation, both the Nu-Vista PAS and PAS PSU can simply be switched to ON or into STANDBY using the POWER/STANDBY button on the Nu-Vista PAS front panel.

WIRING

MUSICAL FIDELITY Nu-Vista PAS High End Hi-Fi Separates-
fig-9 MUSICAL FIDELITY Nu-Vista PAS
High End Hi-Fi Separates-fig-10

PROBLEMS?

Basic problem-solving with an amplifier is similar to troubleshooting other electrical or electronic equipment. Always check the most obvious possible causes first, such as the following examples:

Problem Probable Cause Remedy
No power when POWER button is pressed. Mains power plug is not fully

inserted into rear socket. Power cables between amp and PSU not correctly connected.| Plug in securely.

Connect PA, Control and Nuvistor PRE power cables.

No sound| Unit is starting up, valves are still heating up.

Wrong connections between input sources and the unit

Speakers      not      connected,     or incorrectly wired

| Wait until unit is started up correctly, see page 11.

Check audio input lead connections. Check speaker cables.

Sound cut| Loose connection

Output overload or short circuit

| Check speaker and input connections.

Switch unit off. Check speaker connections for shorting strands or wires. When all has been double-checked reduce volume and switch unit back on.

N.B. Take great care when bi-wiring or bi- amping that speaker bass and treble linking straps are removed; see speaker manual for more information.

Sound is not precise, lacking in bass and stereo image.| Speakers are connected out of phase, i.e., connections to one speaker

(+ and –) are reversed.

| Ensure speakers are connected with same polarity at amplifier and speaker ends.
Hum.| Audio   connector    plug    not    fully pushed in

Cable Fault Unsuitable cable

(e.g. cable grounds not connected)

| Insert plug securely.

Check cable is connected at both ends.

N.B. Some esoteric cables have internal wiring intentionally disconnected/modified. For best results on all inputs analogue AND digital, please use good quality screened coax; signal and screens both separately connected at both ends.

No audio output, or too low level output.| Incorrect or missing connections| Check connections and make sure they are secure.
LEDs are not lighting up.| LEDs can be turned off, in case they are too bright for dark rooms.

Power switch on Nu-Vista PSU is OFF

| See page 11 for display controls.

See page 11 for starting up.

If none of these actions affect a cure, please contact the dealer, or an authorised Musical Fidelity service agent. Remember; never open the case of the Nu-Vista PAS and Nu-Vista PAS PSU, as this will invalidate the guarantee.

SPECIFICATIONS

  • Output power
    • 300W per channel into 8 Ohms

    • Output voltage 49 Volts RMS, 20Hz to 20 kHz; onset of clipping
  • Output current
    • 130 Amps peak to peak
  • Damping factor
    • 200
  • Output devices
    • 5 pairs per channel
  • Gain
    • 16x (23.5 dB)
  • THD+N
    • < 0.003 % typical, 20Hz to 20 kHz
  • Signal/noise ratio
    • 108dB ‘A’-weighted

  • Channel separation
    • 96dB

  • Input impedance
    • 100 k Ohms
  • Input sensitivity for full output
    • 3 Volts RMS
  • Frequency response
    • + 0, –1dB, 5Hz to 50 kHz
Connections
  • Line level inputs
    • 2 pairs line-level single ended RCA connectors
    • 2 pairs line level balanced XLR connectors
  • Line level outputs
    • 1 pair line level single-ended RCA connectors
    • 1 pair line level balanced XLR connectors
  • Speaker outputs
    • 2 pairs of 4mm banana plug/binding posts per side
  • Trigger input and output
    • 3.5mm mono jack socket
  • Trigger level
    • ±5V to ±12V
Power requirement
  • Mains voltages
    • 115/230VAC 50/60Hz (factory pre-set)
    • 100VAC 50/60Hz (alternative)
  • Consumption
    • <0.5W in standby mode
    • 130W on and idle
    • 1060W maximum
Weight
  • Nu-Vista PAS unit only unboxed
    • 27 kg
  • Nu-Vista PAS in the shipping carton
    • 35 kg
  • Nu-Vista PAS PSU unit only unboxed
    • 40 kg
  • Nu-Vista PAS PSU in the shipping carton
    • 50 kg
Maximum Dimensions
  • Nu-Vista PAS (WxHxD)
    • 483 x 187,5 x 475 (494 with connectors) mm
  • Nu-Vista PAS PSU (WxHxD)
    • 483 x 187,5 x 475 (478 with connectors) mm
Standard accessories
  • 1x IEC type mains lead
    • 16-Amp type
  • 2x PA power cable (1 m length)
    • “Neutrik” type
  • 2x Nuvistor PRE power cable (1m length)
    • 5-pin XLR
  • 1x Control power cable (1m length)
    • 4-pin XLR
  • 8x Spike Foot
  • 8x Spike Foot Cup
  • 8x Spike Foot Screw
  • 8x Felt pad for Spike Foot Cup
  • 8x Felt pad for Standard Foot

MANUAL HISTORY DISPOSAL INFORMATION

RELEASE DATE CHANGES
Nu-Vista PAS & PAS PSU 25th November 2022 1st issue

DISPOSAL

The crossed out wheeled bin label that appears on the back panel of the product indicates that the product must not be disposed of as normal household waste. To prevent possible harm to the environment please separate the product from other waste to ensure that it can be recycled in an environmentally safe manner. Please contact the local government office or retailer for available collection facilities.

Musical Fidelity
a Division of Audio Tuning Vertriebs GmbH Margaretenstraße 98, A-1050, Vienna, Austria
www.musicalfidelity.com
Specifications and details are correct as we go to press, but in the interests of product improvement, they may be subject to change during manufacture.

References

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>

MUSICAL FIDELITY User Manuals

Related Manuals