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Reference Series Phono Preamplifier

Reference Series Phono Preamplifier Reference Series Phono Preamplifier Reference Series Phono Preamplifier
Reference Series Phono Preamplifier Reference Series Phono Preamplifier Reference Series Phono Preamplifier
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Reference Series Phono Preamplifier

Introducing the Reference Series Phono Preamplifier...

It came as a surprise to us the number of people asking whether we have any plans
to build a phono preamplifier, not because we doubt the importance of vinyl, but surprising to find so many people still very much into the whole subject as well as many newcomers.

Enjoying both a digital & a high quality vinyl Hi-Fi set up using a phono preamplifier we designed long before setting up the NJC Audio web site, we realised it was time to revisit this subject & get to work designing an entirely new phono preamplifier which could be be a worthy addition to our “Reference Series”, slightly over a year later & much design work & prototyping, we are very happy to be releasing the Reference Series Phono Preamplifier.

Reference quality sound...

The phono preamplifier has been designed to offer a true reference quality sound experience, by this we mean a sound that is not only very enjoyable to listen to, but also technically accurate with minimum deviation from the recommended RIAA curve.

Sound quality is the single most important aspect when it comes to high end audio, while many of our earlier prototypes were very impressive & could easily have been chosen for the final product, instead we decided to keep the phono preamplifier in the prototype stage for a longer period to ensure everything was just the way we wanted it, it was not until several prototypes later with many tweaks & refinements to the design that the final version which you see here was realised.

Reference Series Phono Preamplifier
Reference Series Phono Preamplifier

Suits all Moving Magnet & High Output Moving Coil Cartridges...

Due to the different requirements between moving magnet (MM) & moving coil (MC), rather than designing a combined phono preamplifier capable of accepting both MM & MC cartridges, this would have meant compromises having to be made since MM & MC require a difference design when it comes to the phono stage.

Instead we designed the phono preamplifier with moving magnet in mind, however since high output MC cartridges have very similar requirements to MM, these will also work just as well with the phono preamplifier.

Low output MC cartridges will require our MC Transformer which is designed to work alongside the phono preamplifier to provide the additional voltage gain for MC.

The importance of adjustable cartridge loading...

Moving magnet cartridges have a recommended loading when it comes to both resistance & capacitance, while resistance is standard at 47kOhm the recommended capacitance loading can vary greatly depending on the cartridge, however when it comes to the actual phono stage this is something which is often fixed at a chosen value (usually 100-200pF) of which you have no control over.

While this is fine for most purposes, when you add the capacitance in the tone arm along with the cable capacitance it is easy to end up with a capacitance figure higher than recommended for the cartridge (especially if using longer cable runs), if you are seeking perfection from vinyl then it is important to be able to adjust the capacitance loading to your own preference.

Reference Series Phono Preamplifier
buildquality
Reference Series Phono Preamplifier

Six position capacitance cartridge loading...

The phono preamplifier is designed to give you complete control, therefore we have designed it with user selectable capacitance, this switch being conveniently placed on the front panel allows you to adjust the cartridge loading live while playing music. Six positions are available to fine tune the sound to suit your cartridge, loading can now be whatever you prefer the sound of, perhaps you may prefer different settings for certain albums, there is no right or wrong, just preference, so you can now decide.

Three stage adjustable gain...

We have also included for extra convenience a three position gain switch, this can be used so that the correct amount of gain is used for optimum signal to noise ratio & is just another refinement making the phono preamplifier more of a pleasure to use.

Soft start feature...

The phono preamplifier also includes soft start circuitry, this ensures that any turn on/off transients if present are completely eliminated, which is just one of many refinements we have included in the design of the phono preamplifier.

Hand crafted front panels...

The front panel, volume knob & even the feet are all machined by hand here in the workshop. Crafted from solid aluminium bar stock, they are all individually machined, finished by hand, anodised & then screen printed, these are all individual processes that we perform right here in the workshop.

Reference Series Phono Preamplifier
Reference Series Phono Preamplifier

Quality components for performance & long term reliability...

Inside each reference phono preamplifier you will find some of the highest quality components, such as 1% polystyrene capacitors*, precision Vishay Dale resistors & Elna Silmic II capacitors, each are chosen for performance & long term reliability.

* For increased RIAA accuracy, multiple high quality polystyrene capacitors are used, while these are far more expensive than standard Polyester or Polypropylene often used, they ensure greater RIAA accuracy with no distortion in the signal path.

While it may not be profitable for many manufactures to use such components, we have put so much work into not only the initial design of the phono preamplifier, but also with each & every one we build, therefore we see no point in using cheaper alternatives simply for the sake of saving a little extra on the cost of components.

High overload margin preserves musical transients & prevents clipping...

During the design stage we also paid particular attention to the overload margin, or put simply the maximum input level. Several popular cartridges were tested for output level & while the nominal output of most moving magnet cartridges vary between 3.5mV to 5.5mV (1kHz 5cm/sec), in reality music content contains peaks & transients which were measured at well over 50mV & in some cases 90mV were recorded.

If the amplification circuitry is not designed to handle such peaks then these transients will essentially become clipped, along with the occasional vinyl pop or click which can present even more of a problem. Despite these lasting no more than a fraction of a second, if the amplifier can not handle such levels then it will cause clipping of the signal which in turn causes unpleasant amplifier distortion. How much of an audible difference this makes would then all depend on how well the amplifier handles momentary clipping. At the very least this situation is not correct & is a condition that should never be allowed.

We have taken great care in the design of the amplification circuitry in order to avoid these potential issues. Quite often many phono stages will struggle to provide overload margins of only 30-40mV, while a few may manage to cope with a little higher. However with the phono preamplifier we have been able to provide an extremely high overload margin of 330mV (low gain), 194mV (medium gain) whilst still achieving a highly respectable 93mV (high gain).

This ensures whichever cartridge you decide to use, whether it be a modest 3mV, a high output 5.5mV, or even a cartridge that is known for being very problematic when it comes to overloading a phono stage. You can be assured that the phono preamplifier will faithfully reproduce all music content accurately with clarity & detail, with no possibility of clipping or distorting the signal.

For more information about the Reference Series Phono Preamplifier,
download the PDF below:

pdf
feedback

If you have purchased this phono preamplifier, your comments would be appreciated, please click here to submit your feedback.
(If you could mention the cartridge & any other equipment being used, this would help others who may also own similar equipment)

specifications

Price: 495 + 11.00 Postage
Payment is by 10% deposit with final
payment upon completion.

Delivery to: UK Mainland Only
(See FAQ for more information)

These are individually hand built to order for each person, the time it takes us to build, measure & fully test your preamplifier is currently between 14-18 working days.

 

Please note: If you require a pair of suitable interconnects, please take a look at this page:

 

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NJC Audio - Quality Hand Built Headphone Amplifiers, Phono Preamplifiers, DACs & Interconnects - Hand Made in England

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