Hi Anthony.

Thank you for the privilege of building your NV200 R2 Signature kit. I spent 5 days learning new engineering skills, crimping skills and soldering.

I have been a dedicated DIY valve amp fanatic for more than 50 years and dabbled with a few decent quality solid state amps in that time and had always been disappointed by the clear but harsh sound.

My latest ‘home build’ valve amp is/was an ‘Output Transformer-less’ Transcendental Sound ‘Son of Beast’ running 12 valves including 8 largish EL509s.

The sound is breathtaking and airy with a sound cross between solid state and valve and the transparency is spectacular.

I had a sudden urge to build another amp. Not a valve amp, because I couldn’t see any way of improving my S.O.B system.

After a week of research I came upon Holton Precision Audio which was in Tasmania. How could this be possible?

The reviews for Anthony’s equipment were fascinating because they were from all round the world and the reviews were always glowing.

I thought I would take a chance and order the NV200 kit for around $1000 instead of individual parts because I was struggling to find a decent chassis and couldn’t be bothered ordering bits and pieces from all over. The only other thing I needed was a toroidal transformer.

I managed to get a 500VA toroidal power transformer from au.element14.com for $69 delivered overnight to Qld which seems like a bargain to me.

When my kit arrived I was mesmerized by the beauty and obvious quality of the modules and chassis. Everything was carefully packed into a plastic bag strip.

I studied the modules while I was waiting for the data sheets and schematic for the kit and realised how logical they are to wire up to each other. Once this arrived I was under way.

CONSTRUCTION

My kit is stock standard without any tweaks.

Heat Sinks

The large heat sinks need to be tapped to suit your chosen amp module. I chose to do this myself and bought a 3mm tap and 2.5mm drills from a local bolt supplier for $17.

I had a cheap 30 year old drill press and used it to drill the holes using a perspex template I made to position the holes.

Having never tried to tap thick aluminum before I made the stupid mistake of not lubricating the first hole when I tapped it. The result was not pretty and I ended up drilling right through the heat sink, re tapping it and using a longer bolt.

Soon I discovered some 3 in 1 oil and worked out that I could put the tap into my drill press and rotate it by hand making a perfect thread.

A couple of drops of oil a few twists and I had beautiful threads cut in a few minutes.

Power Switch

Anthony provide a nice looking circular push button on/off switch with an integrated lED. However, the terminals are tiny and by the time I had wired it up I was running out of space to wire up the 12v connection for the LED.

I ended up buying a nice looking 220v LED from Jaycar and drilling a hole above the switch.

The power switch requires a quite large mounting hole. As I didn’t have a large enough bit to do the job I bought a set of 3 tapered bits from Bunnings for $10 and they worked like magic producing a professional looking hole in seconds.

Wiring

Because I didn’t want to attack Anthony’s beautiful modules with my soldering iron yet, I decided to buy a good crimping tool off Ebay for around $26. I recommend buying a good one to make the job easier.

All module power connections use crimped connectors with unheated shrink tube covering the terminals at this stage while I make sure my wiring isn’t causing any unwanted interference.

All power leads have been bundled and I used a screw terminal strip for transformer/wire joins just in case I had to make any changes to the layout. So far so good!

The supplied interconnects are really stiff so you need to be careful with their positioning. I think mine can be improved.

FIRST AUDITION

After checking…checking and rechecking all my transformer wiring I switched it on at the wall and stood back. No smoke no smell! The green amp LEDS were glowing and the current limiter triggered with a nice loud click. Getting more confident by the minute, I checked to make sure there were no nasty surprises if I touched the chassis by measuring the voltage between the amp case and earth with my volt meter.

Coming directly from valve to solid state I was prepared to be a little disappointed but what I heard was smooth, solid and full of detail. I had never heard before in a SS amp. It didn’t sound as transparent as my valve amp but when I listened I realized that the sound of instruments was more coherent and not separated. It sounded more real. I also found I could focus my ears on individual instruments and voices much like live sound.

Piano has never sounded so ‘in my room’. My reasoning is that my valve amp was adding extra harmonics, which sounds beautiful, but in the process this was stopping the natural harmonics and decay of the notes to ‘ring out’.

Guitar is edgier and not as smoothed out as the valve amp.

My valve amp tends to project some instruments and sound in a halographic way that sounds spectacular but actually detracts from the actual performance at times.

I have always noticed a degree of harshness when listening to ‘loud’ female singers. Celine Dion was particularly noticeable when she turned up the volume. Once again this might be caused by the enhanced harmonics on my valve amp but is virtually inaudible with my NXV200.

This amp doesn’t cover up flaws in recordings like a valve amp, but that has to be a good thing.

There is still a lot of listening to do and I find that I am enjoying my CD’s right through instead of favouring individual tracks because I’m ‘enjoying the music’ so much I don’t really notice the sound of ’hifi’ distractions. The bass is outstanding and voice is real.

Well done Anthony. I am delighted to be a customer.

Cheers,
Rob

My equipment:

HPA-NXV200 R2 Signature Amplifier
HPA-Limiter-One R3.0 AC Mains Current Limiter
HPA-LSP-One R5.0 - Loudspeaker Protectors
HPA-Chassis-One
500vA toroidal transformer
Standard speaker sockets
Standard input sockets

Transcendental Sound GG grounded grid valve preamp (kit)

VAF DC-X Generation 4 speakers (kit)

Rega Apollo CD player

Thorns TD160 with Rega 250 arm