NVA AP10P PERSONAL INTEGRATED AMPLIFIER

NEW PRODUCTION NVA AP10P

The AP10P forms the base of the range of integrated amplifier. This is a single input basic low powered personal amplifier of very high sound quality

AP10P Specifications

Inputs - One line level

Outputs - 4mm speaker sockets and 6.5mm headphone socket

Power Output - 15 W per channel

Dimensions - w250mm x h65mm x d205mm (whd)

Hi-Fi News & Record Review

Ken Kessler

If ever a small UK manufacturer has ploughed a lone furrow, it is NVA. Now the indomitable Richard Dunn comes up with a direct-selling amplifier for those on a tight budget.

It was never Richard Dunn's intention to set me on a chase to find the cheapest tolerable mock-audiophile system one could muster. But he did submit for review the NVA AP10 single-input amplifier selling for a paltry £200 and decided to name it the NVA Personal. And personal listening is what this baby is all about; it just happens to cost next to nothing.

What NVA is offering with the Personal almost single-handedly creates a new genre of amp. Indeed, the only thing which preceded it with anything like a similar philosophy was the NAD 3020, also billed in its day as an ideal starter amp. But I can assure you that what cost £89.95 in 1979 would sell for way more than NVA's £200 in 1997.

Because NVA fits neither protection circuitry nor filtering on the outputs, it's best to follow the company's directives. OK, so this is the antithesis of entry-level practice, which dictates that budget gear should be moron-proof Where the NVA departs from the NAD 3020 is that the latter offered a full range of inputs, pre/power separation for upgrades or the insertion of processors, a balance control and so on. The price paid by the user for these extras was some of the nastiest assembly quality this reviewer has ever seen. By worshiping instead at the altar of minimalism, NVA hits its price point without compromising build quality.

What you get with the Personal boils down to this and nothing more: A volume control. An on/off switch at the back. A headphone socket. A pair of speaker terminals. One set of line level phono-type inputs. That's it. If ever an integrated amp appealed to the fundamentally British notion that the presence of any creature comforts means cost-cutting somewhere else, then this is it.

There is but one concession to luxury. Unlike the NAD, the NVA is built to impossibly high levels for the price, right down to a handsome perspex front panel, a recessed red LED to indicate 'on' (which truly disappears when the unit is switched off), reasonable socketry and a pukka 1/4in headphone output instead of the increasingly popular stereo mini-jack. There's a chunky, captive mains lead, real speaker sockets, and a case design, like those of other NVA amps, was determined by sonic concern. Glued together, it is insulated to stop induced circulating currents, and high frequency and high voltage static charge problems. Nothing on this 250 x 65 x 210 mm (whd) case looks like it's gonna break, fall off or do anything to rival the 3020's tackiness. Performance also separates these amplifiers: the NVA actually drives hungry speakers, even though it's only rated at 15W/ch. As it proved in a killer system costing way under £400, this is no glorified headphone amp fitted with a pair of speaker terminals.

But first, some salient philosophy from The Edited and Condensed Richard Dunn Polemic, provided free with every unit:

'This amplifier is designed as a low-cost, high quality, low-powered amplifier for use in a second or "bedroom" system, or with high efficiency (89dB or over) loudspeakers. It is equipped with a standard stereo 6.5mm headphone socket of the front panel. If dedicated headphone listening is required, the loudspeaker cables should be unplugged (just the positive can be disconnected). We tried all forms of headphone switching, both mechanical and electronic relay-based, and the all compromised the sound quality.'

Dunn makes no outrageous claims for this amp, but he insists it's a 'proper' NVA product, just like its dearer siblings. Inside, the single input is routed directly to the volume control with silver-plated cable, the signal then fed to the amplifier PCB, also hard-wired with silver-plated cable. So paramount is the selection of cable in NVA philosophy that the company takes the brave/contentious step of listing the cables it deems acceptable for use with its products. And while its own wires top the list, others include a selection ranging from Ixos to Chord to Rega to QED to XLO. So NVA isn't above recommending products from direct competitors. Cool.

Probably the greatest contribution to the Personals sonic signature is made by its entirely passive pre-amp stage. The input to the power amp section has minimum capacitive and inductive coupling, as Dunn states, 'designed correctly to operate with the variable impedance output of a passive pre-amp stage.' Passive pre-amp fans, take note and glow smugly; this stage helps to make this a transparent and quiet runner. A 'current mirror' operates the pre-driver stage to ensure that the voltage rails track each other correctly. The driver stage has both current and voltage amplification using devices '...that could be used as output transistors,' a fave NVA party trick. The output transistors are two 12A Darlingtons per channel.

Because NVA fits neither protection circuitry nor filtering on the outputs, it's best to follow the company's directives. OK, so this is the antithesis of entry-level practice, which dictates that budget gear should be moron-proof, but the NVA wants to do no more than provide maximum sonic realism for minimal outlay. And if it means treating the amp like a high-end thoroughbred, well, that's part of the appeal: for only £200, you'll have the sort of set-up concerns single-ended triode users are used to.

I quote NVA: 'Do not short circuit the output. Do not use bi- or tri-wiring or high capacitance or Litz-type loudspeaker cables. These could damage the amp as they create a virtual short circuit at very high frequencies. As a rule of thumb, avoid cables with a capacitance per meter of more than 200pF.' In another instant disarming honesty, the literature states, 'The basic circuit of the amplifier is very stable but it is not unconditionally stable. Anybody can make an unconditionally stable amplifier. You just put capacitors everywhere, but it will sound terrible.' Hence the Personal uses the minimum number of capacitors, no inductors and low negative feedback in a Class AB circuit design, which NVA describes as 'unique'. The power supply is designed around a 50VA transformer with a 6A bridge rectifier and 'good quality' capacitors. (Again, the disarming honesty; others would have described them as 'designer caps'.)

As stated before, output is 15Wch, and NVA errs on the side of caution by recommending speakers with 89dB or better sensitivity.

Which didn't stop me from using the Personal with my beloved Quad 77-10Ls, LS3/5As, ad summum, which this amp inspired. Sure, the Personal will drive speakers hungrier that its spec would suggest, but that is simply not the point. Or maybe it is, as this amp is also subject to the NVA practice which states than an NVA 'customer never loses money when he upgrades. Move up to any more expensive NVA amplifier for just the difference in purchase price.' So if you wanted to do everything in reverse, buying big speakers for the Personal, you could trade up to a bigger NVA later on, and not lose a penny. But let's back-track.

Sure, I used the Marantz CD63SE Mk II CD player and nifty tweaks like the Musical Fidelity X-10D and the Theta TLC, both of which are designed to lift budget systems out of the mire. But that wasn't the point.

Pretending that I was yet again - God forbid - a student, with financial problems, flatmates and the need to have a system which could be packed up in a moment and fit in the boot of a Mini, I thought in terms of bargain hunting. Allowing for some Lineaum-equipped Genexxa Pro LX5 speakers is now available for £99 a pair. A 'B stock' Panasonic RQ-S25 personal tape player at Canterbury Hi-Fi Center cost £30, while branded personal CD players are now £79, with 'B stock' selling for less than £50.

Add it up: £200 for the Personal. £100 for a pair of Pro LX5s. £30 for a 'B Stock' cassette player or £60-£80 for a portable CD player, both fitted with a 3.5mm stereo-plug-to-two-phono cable. Throw in some good 24in speaker stands and 3m lengths of speaker cable (£50 apiece) and, by my reckoning, that's just £400 for a system which, with the Personal at its core, can do the following: Boogie Notice I said 'boogie', not 'bang head'. If you want to antagonise those living above, below or on either side of your crib, talk to some poor schmuck who's swallowed all the SET guff about '3W is all you need'; maybe they'll know of a speaker with 96dB sensitivity for £99 per pair. Even so, in a listening area which could qualify as either a normal person's bedroom or the kind of sty most students inhabit - 12 x 16ft - the NVA had no problems driving the Tandys to satisfactory levels.

But the sound? Sweet, smooth and surprisingly transparent, and that applies to both speaker and headphone listening. The sound is robust, with well-rounded, well extended bass, and it wasn't embarrassed driving through B&W's PB100 sub-woofer. Stage width and depth were truly thoroughbred, and it kept reminding me of the dear, departed Rogers Cadet III, which started me on the valve route when money was right. The NVA bounces along, sort of a Citroen 2CV of amplifiers, merrily making music but never pretending to be able to do the impossible. What it lacks in absolute retrieval of fine details, exacerbated by slightly dulled transients, the Personal compensates for with an absence of 'active' nasties. The downside amounts entirely to sins of omission, exactly like the NAD 3020, which never sounded nasty. The NVA, though, never sounds anorexic, either, as did the gutless NAD. This is not a case of Amplifier Lite. The NVA Personal is a real amp for high-end wannabees lacking deep pockets.

Here's my advice: If you just cannot stretch to £300-plus for a complete system and you're dying for some sounds, run - don't walk - to NVA and beg 'em to sell you a Personal. Then, before the imbecile at Tandy learns the error of his ways, buy a pair of Pro LX5s. Next, go to any hi-fi dealer other than a multiple where the prices are as fixed as at M&S, and ask for a B Stock personal CD player. Don't let them lie to you: all hi-fi dealers n the UK circa 1997 are dying for business, even your paltry £50. Seriously broke and prepared to live with headphones for a while? Then don't buy the speakers until you can afford them. Go instead for some £49 Grado SR40s. There you have it: an amplifier for use during a Labour regime.

WE ARE SO CONFIDENT IN THE QUALITY OF OUR PRODUCTS AND DESIGNS WE OFFER 30 DAY NO QUIBBLE RETURNS POLICY

Available in 120v or 240v please stipulate on purchase

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 FOURTEEN DAYS DEPENDING UPON ORDER PRESSURE

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 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.