*ALL* OF OUR PRODUCTS ARE SUPPLIED TO YOU ON A *TRIAL* BASIS. BECAUSE OF THE LOGISTICS INVOLVED YOU HAVE TO PAY INITIALLY. THIS IS TO ENSURE YOU ARE A SERIOUS CUSTOMER WITH THE WHERE WITH ALL. IF YOU ARE THEN UNHAPPY IN *ANY* WAY WITH THE PRODUCT YOU CAN RETURN IT FOR A FULL REFUND, OR IF YOU LIKE WHAT YOU HEAR AND WANT MORE YOU CAN CONTINUE TO DO THE SAME UP THE RANGE UNTIL YOU ARE FULLY SATISFIED.

NVA A60 Stereo Power Amplifier.

REVIEW

The NVA is a power amp designed to be controlled by a passive pre-amp. This minamilist design (sole facilities are an input selector and volume control on the pre-amp and an on/off switch on the power amp) goes to great lengths to maximise quality. The designer has even rejected using screws in the casework - the acrylic panels are glued together.

The pre-amp accepts line-level sources like CD and tuner, but can be used with a separate phono stage, of which NVA makes two models. We've tried the Phono2, and found it excellent.

NVA can also supply speaker and interconnect cable specifically designed for use with its amplifiers. There's a good argument for using these in any NVA system - the power amps are not protected and fancy speaker cables can upset their operation. A set of Sound Pipe interconnects was supplied with the amp. These copper pipes work well in this system.

Without sounding hard, bright or clinical, the NVA peels away anything that obscures the music. Individual instruments and voices stand out clearly, even in the busiest of rock music mixes.

The NVA is a great information-retriever. Unlike many detailed amplifiers, its presentation is lucid and coherent, and it allows music to gel and flow. Timing is very well-judged, but the most obvious strength is with vocals, which have a truly lifelike and expressive character.

The amps clarity and speed lends itself to portraying complex orchestral music. Subtle tempo changes emerge readily, tonal colour and instrumental timbre is explicit, and dynamic variations are exposed candidly. The NVA makes classical music as exciting as rock and jazz, bringing out its character and emotive and dramatic qualities in a spirited fashion.

WHAT HI*FI?

NVA Pre/Power Amplification

NVA's pre/power systems have the greatest number of configuration and upgrade options for building a stereo hi-fi system within the NVA range. There are two main groups of power amplifiers in an NVA system:

· Stereo: Two channel amplifier which includes the A30 and A60.

· Mono-block: Single channel amplifier (which come in matching pairs) this includes the A40, A70 and A80

Stereo models are the most common and integrate power supply and two channels of amplification in a single unit.

With our P50 preamp we have three sets of outputs per channel, so we can not only support a single amplifier but also bi-amping but and tri-amping for speakers with this capability. Lets suppose we start with a P50 and an A30 or A60 amp and a pair of speakers that support bi-amping (most modern speakers).

We can upgrade our system at a later date; for example we add can add another A30 or A60 or the A40, A60, A70 or A80 monoblock power amplifiers:

Here we have the A30 or A60 driving just the tweeters, releaving it of the low frequency current needed to drive bass units. The result is lower distortion, more detail and sweetness. Each A40 drives only a single bass unit and much less crossover. This results in much less intermodulation giving better bass and midrange.

The mono power amplifiers are actually two boxes, and come in matched left/right pairs. This has several advantages each channel is completely independent of the other, and results in less interference between left and right channels, giving better stereo imaging. But the greatest advantage is that each channel has its own power supply. This results in greater dynamics and incite into the music.

Note: not all speakers can be multi-amped, some have only a single pair of binding posts on the back. So in this case we can not obtain better sound with multi-amping. Instead we must simply use bigger amplifiers:

You may be asking yourself this question, "What's better muti amps or single larger amps". Well unfortunately there is no easy answer as it depends on so many variables. But I can give you some guidelines. If your speaker has a complex or high-order crossover, or has a uneven impedance curve (especially around the crossover point) then multi-amping is probably the better route to take. In fact I would recommend the multi-amp route for speakers with 3rd or 4th order crossovers, as each amplifier then `sees' less crossover. If your speaker has a simple (low-order) crossover networks, and even impedance curves then I recommend either solution.

NEW PRODUCTION NVA A60

The A60 is a 60w stereo power amplifier designed to be used only with a passive pre-amp like the NVA P50 and low capacitance loudspeaker cable. It should only be used with NVA LS1 or LS3 cable and Soundpipe or Soundcord interconnects due to the unfiltered nature of the design. Litz or Goetz cable or other designs of high capacitance cable will damage the amplifier.

A60 Specifications

Inputs - two line level

Outputs - 4mm speaker sockets

Power Output - 60 W per channel

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WE ARE SO CONFIDENT IN THE QUALITY OF OUR PRODUCTS AND DESIGNS WE OFFER 14 DAY NO QUIBBLE RETURNS POLICY

Available in 120v or 240v please stipulate on purchase

For full information on NVA go to www.nene-valley-audio.com

NVA's Overall Philosophy

Generally, we have never been keen on producing conventional literature, because it's usually just glossy expensive paper full of pretty meaningless specifications which have little bearing on how good the sound of audio equipment is when playing music. If you buy hi-fi equipment on the basis of what a manufacturer says about himself (including us!) you really do deserve what you get.

As an alternative, one of our dealers suggested that we try to explain good design and how to recognize it. People probably won't believe this, but really the basics are very straightforward. A famous British amplifier designer is supposed to have said, "Good amplifier design is not the things that you do right, but the things you don't do wrong". I really wish I had said it first, because it's amplifier design in a nutshell. You can come up with all the new circuit configurations under the sun such as feed forward, low feedback, class A to Z, but ignore the common sense ground rules, and you will have a sonic bag-of-nails capable of being blown away by a couple of EL34's in a 1950 Williamson tube circuit. I am afraid 80% of the amplifiers built today fall into this category. The thing that never stops amazing me is that so many audiophiles keep falling for it. There is nothing like a good story to have people hocking the next three years' spare income on the latest all-singing, all-dancing creation. Not only that, a good story sells magazines as well, which just exacerbates the problem.

Here are my ground rules:

1. There is only one thing better than the best component money can buy, and that is no component at all.

2. Never use two components when you can do the job with one.

3. Screw up your earth (ground) paths at your peril.

4. Always use the largest transformer (toroid if possible) you can cost in.

5. If your ears and your test equipment tell you two different things, trust your ears.

6. If you have a fault in your source material or elsewhere in the equipment chain, you cannot correct it by creating an inverse fault in the amplifier with tone, balance, and filter controls. Two wrongs do not make a right.

After that it is all down to experience, and fine-tuning the design to your own taste. It is easier to get a half-way decent sounding amp using Vacuum State Logic (warm glass bottles) than Solid State Logic (hopefully cool lumps of plastic) because there is less to do wrong (Neanderthal Logic). That is why so many people have jumped on the valve bandwagon. All things being equal, bits of doped silicon encapsulated in metal or plastic (transistors) potentially are capable of doing more things with music, i.e. wider (frequency), larger (amplitude), cleaner (distortion and noise) for less cost. Remember though, the more you try to do, the exponentially easier it is to do it wrong.

If you can get most of it right, then think very carefully before you try to get the very last bit, because you may be too clever and ruin everything you've gained thus far.

This explanation is all very simplistic of course, and common sense and experience must apply as well. For example, a Class A circuit is a lot simpler that the equivalent Class B or AB. Ergo, applying my logic it should be better. Wrong, unless you spend a fortune on the power supply, which then makes the amplifier grotesquely expensive and heavy. The problems of current demand by the amplifier outweigh the simplicity. If I could buy 1000VA transformers not larger than 4" square, and weighing less than two pounds for £10, and if I could get good and consistent output transistors (i.e. not FETs) that could sink 20 amps, and either, not get hotter than 70 degrees C doing so, or stand 150 degrees C without going into self-destruct mode, I would produce Class A amplifiers. I will not produce them just because they have become some reviewers latest buzz word.

Every amplifier has its own sonic character, which is very much down to the musical parameters that are most important to the designer. The process is very much "lose on the swings, gain on the roundabouts". I once knew an amplifier designer, in fact I employed him back in Tresham Audio days to produce a professional FET power amplifier, who saw no necessity for listening to the amplifier at all. It was only after he left, and some ears were applied to the design that it started to sing, not as much as the best hi-fi amplifiers, but it went very loud and was virtually indestructible.

My greatest hang-up is information retrieval - musical information, especially dynamic separation. I will always go for information even at the expense of upsetting the "make everything bounce and swing with the tempo" brigade. My other priority, which seems to be out of favour at the moment, is neutrality, or as I prefer to call it, lack of the irritation factor.

Richard Dunn, Founder and Owner, NVA

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PLEASE NOTE ALL NVA PRODUCT IS BUILT TO ORDER SO THERE WILL BE A DELIVERY DELAY AS THE PRODUCTION AND TESTING IS SCHEDULED. AVERAGE DELIVERY TIME IS FIVE TO SEVEN DAYS BUT CAN ON OCCASION GO OUT TO TEN TO FOURTEEN DAYS DEPENDING UPON ORDER PRESSURE

 

PRICE LIST

ELECTRONICS

AP10H Headphone Amplifier £240.00

AP10P Personal Integrated Amplifier - £260.00

AP20 Integrated Amplifier - £350.00

AP30 Integrated Amplifier - £450.00

AP50 Integrated Amplifier - £550.00

AP70 Integrated Amplifier - £700.00

AP80 Integrated Amplifier - £1000.00

P50 Passive Pre Amplifier - £160.00

P50sa Passive Pre Amplifier - £260.00

P90 Passive Pre Amplifier - £240.00

P90sa Passive Pre Amplifier - £540.00

P90 Passive Pre Amplifier plus active phono stage - £350.00

P90sa Passive Pre Amplifier plus active phono stage - £650.00

RVC Remote Volume Control - £120.00

A30 Stereo Power Amplifier - £300.00

A40 Mono Power Amplifiers (pair) - £400.00

A60 Stereo Power Amplifier - £600.00

A70 Mono Power Amplifier (pair) - £800.00

A80 Mono Power Amplifier (pair) - £1000.00

P.S.U. Power Supply for Phono2 and Dacon - £190.00

Phono1 Head / Phono Amplifier (in built psu) - £220.00

Phono2 Head / Phono Amplifier - £260.00

Phono PCB’s – for fitting to nva products – £100.00

CABLES

Sound Cord – per 10cm length pair – terminated - £5.00 (SEE SPECIAL OFFERS)

Super Sound Pipe – per 10cm length pair – terminated - £20.00

Sound Pipe – per 10cm length pair – terminated - £10.00

Sound Pipe Digital – per 10cm length - terminated - £5.00

LS1 – per metre length stereo set – terminated - £20.00

LS2 - per metre length stereo set - terminated - £10.00 (SEE SPECIAL OFFERS)

LS3 – per metre length stereo set – terminated - £30.00

LS5 - per metre length stereo set - terminated - £50.00

Sound Pipe LS - per metre length stereo set - terminated - £100.00

Bi-Wire – per end (speaker and amp) – terminated - £10.00

We offer a 100% trade in value on our products if you trade up within the nva range of like products within two years of your purchase date (only applicable to direct sales from us or through ebay). After that date we will still trade in your item but on a sliding scale as to age and condition. You must print out and keep your ebay receipt or invoice to verify your purchase date.

THIS SERVICE AND OFFER IS QUITE UNIQUE IN THE WORLD OF AUDIO AND HI-FI

NVA AND SPEAKER CABLE SAFETY

For best sound the amplifier should be left powered up. Electricity consumption is very low. It is for this reason that the power switch is located on the back panel, where it may not be easy to reach. Turn the amplifier off when you do not intend to listen to it for extended periods.

NVA amplifiers are unique, and one thing that makes them so is the minimal compensation for the output stage. It is very possible to send this amplifier into oscillation by connecting too large a capacitive load on the output, the usual culprit being unsuitable speaker cable such as Litz or Goertz type constructions. The amplifier normally runs cool, but if it is driven unstable the output transistors will become hot and the sound will distort and the amplifier could fail putting your loudspeaker coils in danger. You can check for this by placing your hand on the amplifier and feeling for hot spots. If you find the amplifier overheating switch off immediately and consider changing your cable.

Only NVA LS1, LS2, LS3, LS5 or SPLS is recommended for use with this amplifier, other cables invalidate our guarantee. If you insist on using other cable please ensure it is no more than 200pf per metre and it should not be used in lengths over 10 metres. If you wish to Bi-Wire this can only be done with NVA cable and they can be made that way on order for small added cost.

For design performance only NVA Soundpipe Super Soundpipe or Soundcord  Interconnects should be used, but this is for sonic as opposed to safety reasons.