Naim Audio NAP-250 Owners manual

W O R L D C L A S S H I F I

O W N E R S M A N U A L I S S U E 1

Power amplifiers: NAP 500, NAP 300, NAP 250, NAP V145, NAP 200, NAP 150, NAP V175

	Introduction
	Naim Audio products are always conceived with performance as the		CONTENTS
	top priority and careful installation will help ensure that their full
			Page	Section
	potential is achieved. This manual begins with statutory safety		1	1 Equipment Installation
			1	2 Cables and
	warnings and general installation tips for all Naim Audio products.			connections
			1	3 Getting Started
	Product specific information begins in Section 6.
				3.1 switching on and off
			2	3.2 running in
				3.3 mains supply
				3.4 siting the equipment
	1 Equipment Installation			3.5 if you have a problem
			2	4 Warnings
	Normally your Naim equipment will have been installed by the dealer who sold it to you		3	5 Connection
	even if you live outside their immediate vicinity. Your dealer is responsible for making			5.1 mains lead
	sure that the system sounds exactly as it should and information given here is not			5.2 non-rewireable mains
				plugs
	intended to reduce this responsibility in any way.
				5.3 fuse carrier
				5.4 plug fuses
			4	6 NAP 500
	2 Cables and Connections		5	7 NAP 500 Connection
	Please do not modify the standard interconnect cables			and Specifications
			6	8 NAP 300
	supplied with your Naim equipment. This is important for
			7	9 NAP 300 Connection
	safety as well as performance. One end of each cable is
				and Specifications
	marked with a band to establish its correct orientation.		8	10 NAP 250
	The band always marks the end that connects to the		9	11 NAP 250 Connection
	signal source.			and Specifications
			10	12 NAP V145
	Loudspeaker leads are also very important. Naim		11	13 NAP V145 Connection
				and Specifications
	loudspeaker cable is correct for your system and your
			12	14 NAP 200 & NAP 150
	dealer will make up leads to suit your equipment
			13	15 NAP 200 & NAP 150
	installation. The leads should each be at least 3.5 metres
				Connection and
	long and of equal length. The recommended maximum is			Specifications
	20 metres. Loudspeaker leads are, like interconnect leads,		14	16 NAP V175
	directional, and should be connected so that the printed		15	17 NAP V175 Connection
				and Specifications
	arrow points towards the speakers. Using alternative
			16 Standards Declaration
	loudspeaker cable will degrade performance, and may even
		3 Getting Started
	damage your amplifier. An exception to these loudspeaker
	cable constraints is the NAP 6-50 multi-room power
	amplifier. The NAP 6-50 is designed to be tolerant of both	3.1 switching on and off
	a wide variety of cable types, and cable runs well in excess	Source components and power supplies for cd players,
	of 20m. The loudspeaker connectors supplied with all Naim	tuners, preamplifiers and crossovers should be switched
	amplifiers and loudspeakers have been specifically	on before switching on the power amplifier(s). Always
	designed to make a robust mechanical connection. It is	switch the amplifier(s) off and wait about a minute for
	essential that these are used in order to comply with	the power supply capacitors to discharge before
	current European safety regulations.	connecting or disconnecting any leads. Always use the
		power switch on the product rather than a mains outlet
	All the plugs and sockets supplied with your Naim	switch.
	equipment have been chosen because they make the best
	possible connection for their purpose. A poor contact will	3.2 running in
	degrade the signal substantially and plugs and sockets	Your Naim equipment will take a considerable time to run
	should look clean and free from corrosion. The easiest way	in before it performs at its best. The duration varies, but
	to clean them is to switch off the equipment, pull the plugs	under some conditions you will find that the sound
	out of their sockets, and push them back in again. Special	continues to improve for as much as five weeks. Better and
	contact cleaners and contact enhancers should not be	more consistent performance will be achieved if the system
	used as they tend to deposit a film which is very difficult to	is left switched on for long periods. It is worth remembering
	remove and may degrade the sound.	however that all electronic equipment can be damaged by
		lightning. Please read the warnings section.

1

Introduction

3.3 mains supply

Where fused plugs are used 13 amp fuses should be fitted. Fuses of a lower rating will fail after a period of use.

A hi-fi system usually shares a mains circuit with other household equipment some of which can cause distortion of the mains waveform. In some Naim equipment such distortion can lead to a mechanical hum from the transformers. The hum is not transmitted through the speakers and has no effect on the performance of the system but is purely local to the transformer itself. A separate fused mains circuit (like that reserved for electric cookers) may reduce transformer hum. Such a circuit (ideally with a 30 or 45 Amp rating) will also have a lower impedance, supply cleaner power, and consequently improve system performance.

Do not wire voltage dependent resistors or noise suppressors into mains plugs. They degrade the mains supply and the sound.

IMPORTANT

In order to comply with current European safety regulations it is essential that the Naim loudspeaker connectors supplied with amplifiers and loudspeakers are used.

Do not under any circumstances allow anyone to modify your Naim equipment without first checking with the factory, your dealer, or your distributor. Unauthorised modifications will invalidate your guarantee.

For your own safety do not under any circumstances open Naim equipment without first disconnecting the mains.

The following label is attached to all mains powered equipment:

W A R N I N G

THIS APPARATUS

MUST BE EARTHED

2

3.4 siting the equipment

Power supplies and amplifiers should be located a reasonable distance away from other equipment. This separation will stop transformer radiation causing hum audible from the loudspeakers. The maximum separation distance for connected equipment is that allowed by the standard interconnect lead.

Some Naim equipment is extremely heavy. Ensure that your equipment rack or table can easily support the weight and is stable.

3.5 if you have a problem

Legal consumer protection varies from country to country. In most territories a dealer must be prepared to take back any Naim equipment he has sold you if he cannot make it work to your satisfaction in your own home. A problem may be due to a fault in any part of the system or its installation so it is essential to make full use of your local dealer’s diagnostic skills on site. Please contact your local distributor, or Naim at the address in the back of this manual, if any difficulties cannot be resolved. Some Naim equipment is made in special versions for different territories and this makes it impracticable to arrange international guarantees. Please establish the guarantee arrangements with your own dealer at the time of sale. We are always available to offer help and advice.

It is essential that repairs and updates are only carried out by an authorised Naim dealer, or at the factory by Naim itself. Many components are made, tested or matched specially for Naim and appropriate replacements are often unobtainable from non-specialist sources.

4 Warnings

Naim equipment is designed to offer the finest sound quality that can be achieved avoiding compromise wherever possible. This can lead to circumstances that may be unfamiliar. The material that follows contains advice specifically related to Naim equipment as well as more general warnings about the use of domestic audio products. Please read it carefully.

The transformers in Naim power amplifiers and power supplies may sometimes make a mechanical noise caused by distortion of the mains waveform. Naim transformers are large in size and have heavy gauge secondary windings making them relatively sensitive to such distortion. A separate mains circuit for your hi-fi system may reduce the effect while also giving an overall improvement in sound quality. It may be necessary however to take account of mechanical transformer noise when siting your equipment.

Introduction

In some circumstances, depending on where you live and the earthing arrangements in your home, you may experience radio frequency interference. Controls on broadcasting in some territories allow very high levels of radio frequency radiation and both the choice and exact siting of equipment may be critical. If there is a known problem in your locality it is advisable to arrange for a home demonstration before purchase to find out if Naim equipment is likely to be affected. Susceptibility to radio frequency interference is related to the wide internal bandwidth necessary for high sound quality. Systems incorporating moving coil phono preamplifiers and active crossovers are more likely to suffer. A radio frequency filter kit is available for some Naim equipment but sound quality will be progressively compromised as more elements of the kit are fitted. In situations of extreme radio interference Naim equipment may be unsuitable.

Your Naim hi-fi system can be damaged by lightning. Power amplifiers are particularly at risk and should be turned off when there is risk of lightning strike. For complete protection all mains plugs and any aerial cables should be disconnected when not in use.

Equipment must not be exposed to dripping or splashing and no objects filled with liquid, such as vases, should be placed on the equipment.

Use of non-standard speaker cables or interconnects may invalidate your guarantee.

5 Connection

5.1 mains lead

As the colours of the wires in the mains lead of this apparatus 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 by the letter E or by the safety earth symbol or coloured green or green-and-yellow.

The wire which is coloured BLUE must be connected to the terminal in the plug which is marked with the letter N or coloured black.

The wire which is coloured BROWN must be connected to the terminal in the plug which is marked with the letter L or coloured red.

5.2 non-rewireable mains plugs

If a non-rewireable plug is cut from a mains lead (for whatever purpose) the plug MUST be disposed of in a way to render it totally unusable. Considerable shock hazard exists if the cut-off plug is inserted into a mains outlet.

5.3 fuse carrier

Should the plug fuse carrier be damaged or lost, the correct replacement must be obtained from your dealer, or from Naim Audio direct. Do not use the plug until the fuse carrier is replaced.

5.4 plug fuses

Replace only with ASTA or BS 1362 approved fuses.

NOTE

This equipment has been tested and found to comply with the relevant EMC and Safety Standards, and, where applicable, also complies with the limits for a class B digital device, pursuant to Part 15 of the FCC Rules.

These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

•Reorient or relocate the receiving antenna.

•Increase the separation between the equipment and the receiver.

•Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

•Consult your Naim dealer or an experienced radio/TV technician for help.

3

NAP 500

6 Installation and Operation

The NAP 500 and NA PS500 should be installed in their final operating locations before connecting cables or switching on. Switch on the source and preamplifier components, with the volume turned down, before switching on the NAP 500. The NAP 500 power button is located on the front panel of the NA PS500 Power Supply.

Care should be taken when siting the NAP 500 to ensure that the top and bottom ventilation grids are not blocked e.g. by carpet if the unit is to be placed on the floor.

The NAP 500 is very heavy and care should be taken when lifting or moving it. Make sure that the surface it is to be placed on can support the full weight.

6.1 connections notes

6.3 loudspeaker cable and connectors

The negative input and output connections for each channel are common. The mains earth (ground) should always be connected regardless of what other equipment is used in conjunction with Naim power amplifiers. This only grounds the case and the electrostatic screen within the transformer, and is not connected to the signal negative. In order to avoid hum loops, the signal negative of the whole system should be connected to the mains earth (ground) in one place. This should be the primary signal source.

Note: Each channel of the NAP 500 is a “bridged” amplifier, so none of the speaker outlet sockets (+ or -) is at earth potential. Avoid connecting mains powered equipment such as electrostatic speakers, sub-woofers and headphone energisers that do not have a floating earth. No plug which is connected directly or indirectly to earth potential should be attached to any speaker outlet (+ or -).

Only Naim Audio speaker cable should be used to connect a loudspeaker to the output of the NAP 500. Custom Naim Audio loudspeaker connectors are supplied to make the connection. IN ORDER TO COMPLY WITH CURRENT EUROPEAN SAFETY REGULATIONS IT IS ESSENTIAL THAT THESE ARE USED.

DAMAGE TO THE AMPLIFIER MAY RESULT IF “HIGH DEFINITION” CABLE OR ANY OTHER SPECIAL CABLE IS USED TO CONNECT THE LOUDSPEAKERS.

6.2 protection notes

In the NAP 500 the fan speed is increased in response to an increase in amplifier dissipation. If the amplifier reaches 70°C due to prolonged running at high level or to airflow being blocked, the output will be interrupted and the fan will run at full speed until it has cooled down. This may take a few minutes.

It is not necessary to switch the amplifier off, but it may be advisable to mute the preamplifier or turn the volume down to avoid surprises when it comes back on.

OPERATION OF THE AMPLIFIER’S THERMAL PROTECTION SUGGESTS PROLONGED USE AT TOO HIGH A VOLUME LEVEL. YOUR LOUDSPEAKERS MAY BE AT RISK IF THIS IS THE CASE. THE VOLUME SHOULD BE REDUCED.

4

NAP 500 Connection & Specifications

7.1 NAP 500 connection to NA PS500 Power Supply

		+ -		- +
	1					2

to preamp power	left	right	to preamp power
supply. left, ch1		speaker ch2	supply. right, ch2
	speaker ch1

NA PS500 rear

mains in

Input Socket 1

Input Socket 2

7.2 Specifications

ch1

-ve

nc

-ve

NAP 500 & NA PS500

Power Output

nc

ch 2

Continuous, 8 ohms

140 Watts per channel

Transient

700VA

Quiescent Power Consumption

60VA

Voltage Gain

+29dB

Input Impedance

18 kilohms

Frequency response

-3dB @ 1.5Hz and 100kHz

Mains Supply:

100V. 115V. 230V - 50/60Hz

Case size (H x W x D)

NAP 500

160 x 432 x 375mm

NA PS500

87 x 432 x 314mm

Weight

NAP 500

25.0kg

NA PS500

15.4kg

5