Avondale Audio Naim NAP 250 upgrade

Introduction

Regular readers may recall my admiration for the New Naim Classic equipment, which is tempered by the unattainable costs involved coupled with the lack of value in trading in the Old Naim Classic equipment. As such, an upgrade journey began on the existing electronics, firstly with Chord Company and others, which has improved performance considerably. These ideas were outlined in this article and video.

One comment on my Naim Upgrade video from @patthewoodboy piqued my interest in Yorkshire-based Avondale Audio, and a few phone calls with Les Wolstenholme have led to this piece discussing the Avondale Audio upgrades available on Old Naim Classic products.

Design

This is an article on an Avondale upgrade to an Old Naim Classic NAP 250.2 power amplifier.

Avondale Audio modified the NAP250 by removing most if not all, of the original components and replacing them with custom-designed alternatives.  The amplifier module becomes a fully complementary circuit design that is easier to balance sonically than the quasi-complementary designs, often favoured by Naim and others. Being unconditionally stable, any length and manufacture of loudspeaker cable may be used with this amplifier.

Several design ideas are incorporated in the Avondale NCC300 amplifier module, including having the front end of the power amplifier served with its own power regulator to ensure it remains unaffected by output loads. The multiple output devices have their own Schottky rectified capacitor bank, allowing a current delivery to low-impedance speakers without limitation. This is achieved with a custom-designed transformer with two separate windings delivering to the two circuits.  This twin-core transformer custom design ensures that DC saturation of the usual single core does not occur – leading to much lower mechanical and harmonic noise being generated.

Other features of the Avondale conversion include a soft start to the loudspeaker, this obviates the pops and thumps pre Naim DR users know and love. This circuit maintains a watch on amplifier operating conditions, and should any fault be sensed, immediate disconnection of the loudspeakers is the result. A mains soft start incorporating a thermal protection device removes pressure on the transformer with a time delay.  Once completed by Avondale, these modifications all combine to ensure that the unit does not need regular servicing (10 years or so), Naim recommends.

In addition, I have an Avondale preamplifier. This, too, is a unique piece of equipment with its own separate power supply that is functional in design but extremely effective. The power supply is a shunt design, described as the equivalent of driving a car with the accelerator flat out and managing the speed by using the brake. Thus, the preamplifier, in this case, has all the power it needs whenever it is needed.

The preamplifier is designed in transistor form to resemble a single-ended valve amplifier. It features a Japanese Noble volume control that clicks through mechanically. Three RCA inputs and a single RCA output are provided, and the power is delivered by a supplied 5-pin DIN lead.

Quality

The Avondale NAP 250 is extremely heavy relative to my old, unDR’d NAP 250.2. The feel and finish are the same as the old NAP, with the same green logo, though slightly paler than my own.

The preamplifier is approximately a quarter-width (in two parts), with a 5-pin DIN supplying the power to the pre from the power supply.

Specification and Price

Performance

Review Equipment

Initially, I had the Avondale NAP 250 hooked up to my own NAC-N 272 preamplifier, which was driving my KEF R700 loudspeakers. I now have my NAC-N 272 isolated with three Node Audio SS-1s, which are a proper isolation upgrade. I was using the Chord Company SignatureX Tuned ARAY 4-pin DIN to feed the NAP.

The second part of the process necessitated moving the Avondale preamplifier’s straight RCA output to the 4 PIN DIN supplied by Avondale since the preamplifier output is RCA only (where the NAC output is 4-pin DIN).

I was using a super clean Nuprime DAC-9X fixed output to the Avondale preamplifier with Atlas Mavros RCA interconnects with GRUN with an Auralic ARIES streaming transport, connected with an Atlas Mavros USB B cable with GRUN. The 250s are driving Kudos Audio Titan 505s.

In direct comparison with the New Naim Classic NAP 250, I needed to commandeer some studio-sourced RCA – XLR Male leads to feed the New Naim NAP.

Physically

The Avondale NAP 250 is heavier and otherwise has no distinguishing features to comment on. The lack of thumps on power down was my only noticeable observation.

Avondale Audio NAP 250 upgrade

Initially, I placed the Avondale Audio NAP 250 in place of my own NAP 250.2 with my NAC-N 272 preamplifier. The upgrade was night and day; it is a wholly heightened soundstage with greater energy in the room. The high midrange and treble of the soundstage was a fraction more forgiving. I’m using Ryan Adams’ Gold (TIDAL 24-bit, 96kHz FLAC) as a reference album since it is very familiar to me with layered guitars and dynamic passages. The bass response, too, even with the KEFs has a greater degree of heft, as I noted in the Tellurium Q Ultra Silver II review last week when playing Lana Del Rey’s A&W (Qobuz FLAC 24 bit, 48kHz).

Replacing the Avondale Audio NAP 250 with a New Naim Classic NAP 250 offers a similar performance uplift. I have spoken of the easing in the upper ranges with the New 250; there’s not much between the New Classic 250 and the Avondale 250, although there is in price terms.

Fundamentally, I know I need to service my NAP 250.2, having recently done the same with the 272, but this change of presence is compelling with Avondale, be that versus the Old or the New Naim Classic 250. Removing the Avondale 250 was a very dispiriting affair indeed.

Avondale Audio preamplifier

Moving to the reference system to play with the preamplifier was an eye-opener. Les Wolstenholme at Avondale noted that the preamplifier was his game-changer, so I had to try this.  I moved the Old and New Naim NAP 250s into a room with a pair of Titan 505s and the above setup with the Nuprime DAC-9X.  The 9X is more forgiving than the Nuprime DAC-9SE but still crystal clear in fixed output mode; it is a high-end studio quality joy.  The Avondale preamplifier is a perfect partner and reveals every beat of Gold with precision and musical joy.

Naim Audio New Classic or Avondale Audio or Moor Amps

On the mythical desert island, I’m taking the Titans, and it might be that this three-input preamplifier will do it with this DAC and a Michell GYRO SE.  I can’t decide if I would take this Avondale NAP 250 with me to the desert island or my Moor Amps Angel 6; I’d likely choose the latter if I were put in a corner but not if I had a tight budget, the Avondale package is stunning value.

Thoughts

I have talked a lot about Naim upgrades on this website, the journey has probably concluded here. The Chord Company upgrades, the Node Audio isolation and further upgrades to the preamplifier have all tempered my desire for the Naim New Classic equipment. One can only ponder how an upgraded Avondale solution can be so effective over the new equipment, one suspects the accountants are involved somewhere.
I can only extend thanks to @patthewoodboy for putting me onto Avondale through the YouTube video comments.

For me, a New Classic NAP 250 remains unaffordable, given the pitiful value I’d get for my own 250. My next step is to look at servicing my existing NAP 250 (for around £495, via the excellent Music Matters in Stratford On Avon). If I were to do anything with my existing NAP, I would certainly be booking in with Avondale if they have the capacity available without hesitation.

Overall

Without reservation, Avondale is offering a leap in performance to Old Naim Classic NAP 250 owners who can only look wistfully at the New Naim Classic equipment.