The Unofficial Naim Audio FAQ


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  • Power Supplies

    What's the difference between the various Naim power supplies

    There are three main models of Naim power supply for powering different pieces of equipment (pre-amps and other devices).  There are also more specialised supplies for powering specific pieces of equipment.

    The FlatCap2 is a new power supply designed primarily for use with the 5 Series (the CD5, Nait 5, etc.).   It is unique amongst the Naim power supplies in that it can be used to power more than one piece of equipment.  It replaces the original FlatCap which was a half height unit generally only used within the 'slimline' range (i.e. the CD3.5, 92/90 amplifiers). 

    The HiCap is a half width full height unit which is considerably more refined than the FlatCap and is the most commonly used Naim power supply.  It is used to power preamps, active crossovers, the Prefix phono stage and the Headline headphone amplifier.

    The SuperCap is a full width, full height component with a number of individual, separately regulated power supplies on board. Each of these separate supplies is used to power different sections of a piece of equipment independently.  It is the most sophisticated, refined and expensive of the Naim power supplies

    What about power supplies  for CD players?

    The XPS is a power supply similar in sophistication to the SuperCap but designed to power Naim CD players.  It is an optional upgrade for the CDX but is required for the CDS2.  It cannot be used to power a CD3.5 or other Naim components such as preamps, crossovers, etc.

    Although the CD3.5 and CD5 cannot be used with the XPS they can be upgraded with an external power supply - specifically a FlatCap, HiCap or (rarely) a SuperCap.  In this case the external power supply is providing a single regulated power supply for the analogue output stages of the CD player whereas an XPS powers each major part of the CDX or CDS2 with a separately regulated supply.  Adding a power supply to a CD3.5 therefore provides less of an improvement - albeit for much less money - than an XPS does for a CDX.

    The CDX can be used standalone or with an XPS. It cannot be used with the other power supplies like a CD3.5.

    The original CDS had a dedicated power supply similar to the XPS but called the CDPS which can only be used with an original CDS.

    What about power supplies  for turntables?
    Naim make a dedicated turntable power supply for the Linn Sondek LP12 called the Armageddon. They also used to make a power supply  for the Phonosophie turntable.

    What's a NAPSC?

    A small power supply to control the front panel electronics (e.g. the motorised volume controls back lighting, etc.) of some Naim preamplifiers. It is an optional upgrade to a 102 and is provided as standard with an 82. A 52 doesn't need a NAPSC as the equivalent function is provided by the SuperCap.

    A NAPSC can also be used to power the Naim Headline headphone amplifier.

    What's a *Cap?
    *Cap is an informal written shorthand for the core range of Naim power supplies - the FlatCap, HiCap and SuperCap.

    Who did the power supplies get their names?

    The HiCap came first and it name means High Capacity.  The SuperCap is a more powerful and sophisticated power supply than the HiCap and is therefore presumably a "Super" version.  

    The FlatCap is half the height and twice the width of a HiCap and is therefore flat.  In the UK a Flat Cap is also a type of hat favoured by older men from the Northern counties of England

    Why do dedicated power supplies make such a difference?

    There are a number of reasons.  Firstly Naim power supplies are of very high quality. Naim pioneered the use of well designed and highly specified power supplies in audio applications 25 years ago and are widely regarded as leaders in what has become well accepted as an important  aspect in the design of hi-fi components.  Specifically Naim power supplies provide an exceptionally low noise and accurately regulated supply which brings great benefits in such highly critical audio applications.  

    Secondly a power supply is a relatively noisy component in electrical terms and this noise can cause problems in an audio circuit - especially with the delicate low level signals found in preamplifiers.  Hence placing the power supply in a separate box can also bring major benefits.  This is also the reason why you should site power supplies and power amps (which also contain a power supply) as far away as practical from preamps, CD players and crossovers.

    Also note that the more sophisticated power supplies - the SuperCap and the XPS - provide a number of separately regulated supplies to the different component parts of the single piece of equipment they are powering.  This further increases the performance of the component being powered.  This also applies to the use of multiple HiCaps to power different parts of an 82 preamplifier.

    Should I upgrade my preamp to a better model or add a power supply?

    Opinions do differ although most Naim owners would strongly advise adding a HiCap to any Naim preamp from the 72 upwards if at all possible.  Note that many people would not use a FlatCap to power a preamp other than the 92 and would consider the increased performance of a HiCap much better value.

    There are other things to consider in addition to which sounds the best.

    1. A power supply can be retained and used to power another component including a better preamp.
    2. Adding a HiCap means you can upgrade without losing money by trading in your existing preamp.
    3. Using a separate power supply allows you to use the 250 and 135 power amps and therefore opens up more upgrade options.  This is particularly useful if your speakers require more power and/or you have a relatively large room.

    Should I add a FlatCap or HiCap to my CD3.5 or CD 5 or upgrade the CD player to a CDX?

    Most people would prefer the CDX over a CD3.5 or CD 5 + HiCap.  However bear in mind the following:

    1. A FlatCap or HiCap bought for a CD3.5 / CD 5 could always be used to power another piece of equipment should the CD player be upgraded at a later date.
    2. A CDX has a further upgrade path through the XPS power supply to the CDS2 which is not available with a CD3.5

    Generally nobody would use a SuperCap on a CD3.5 although it is possible.

    If I have one FlatCap or HiCap should I use that to power my CD3.5 or my preamp?
    Or if I have a FlatCap and a HiCap should I put the HiCap on my  CD3.5 or my  preamplifier?

    Again opinions differ on this although its easy enough to swap them over so you can decide for yourself which is most effective.

    Note if you have a FlatCap2 it can be used to power both a CD player and a preamplifier.  Typically it would be used to power a CD 5 and a Nait 5 or NAC 112.

    I've heard of people using SuperCaps where one would expect to use only a HiCap. Why is this?

    It is possible to use a SuperCap where a HiCap would normally be used. For example, to power a Prefix or preamps such as the 102, 72.  In this situation only one of the SuperCap's regulated supplies is being used so one may be inclined to view this as a poor value since you are paying for a lot of capability  you are not using

    However a sizable number of people think its worth the expense and claim an improvement over a HiCap. Others think that while there is an improvement its not worth the extra money. The improvement is probably due to the larger, higher rated transformer in the SuperCap and the higher tolerances used when selecting individual components that are used to make a SuperCap.

    Using a SuperCap on an 82 is a more obvious option as the 82 can accept two separate power supplies so two of the SuperCap's outputs are used.

    Also bear in mind that using a SuperCap on a  preamp other than the 52 can be a useful half way step towards a 52 and this may influence your decision if you are aiming for a 52 at some point.

    I've heard some people make their own power supplies instead of buying Naim ones. Is this a good idea?

    A number of people have made their own power supplies which mimic the designs of HiCaps and Armageddons.  If you are interested in electronics this can undoubtedly be an enjoyable and interesting exercise and many people have managed to improve their hi-fi for modest sums of money and a few weekends of their time.

    Naim have listened to a number of "home-made" power supplies and have said that in all cases the DIY supplies objectively measured and subjectively sounded worse than the real thing.

    Obviously to undertake this sort of thing you need to have a deep knowledge of electronics, you are risking severe damage to your Naim equipment and will invalidate your warranty

    Copyright © 1999-2001, Matthew Robinson. All rights reserved