The Audio Appraisal Reference Hi-Fi System

Please see This Post for a detailed rundown of our reference system.


I’ve reviewed many components here on Audio Appraisal, yet I’ve never written about the test system in detail. The system mostly remained the same for years and consisted of Marantz’s recent flagship PM-11S3 integrated amplifier, a Technics SL-1210 turntable with Audio-Technica AT33PTG/II cartridge, and the 851N streamer / DAC from Cambridge Audio. A few other components came and went including various CD players and transports, a cassette player or two and a Technics RS-1500 open reel machine which is currently awaiting a full restoration.

I come from a pro audio and engineering background where many of the audiophile beliefs and eccentricities are openly mocked, and rightly so. When I assemble a system, there are a few key factors in my decision to use any given component.

Technical Design

There are many heavily praised components in this industry which are in reality quite poorly designed, technically speaking. They either do not measure at all well (why do some manufacturers avoid publishing measurements?) have major reliability or safety flaws, or require expensive ‘upgrades’ to get the best from them – a typical example being an outlandishly expensive upgrade power supply. A component must be competently designed, sensibly priced and measure well in objective tests.

Subjective sound quality

Note the word subjective here. Tastes differ from person to person. How a product sounds can differ between individuals, rooms and systems. This is the reason I don’t devote a majority of my reviews to discussing the subjective sound of a product. Subjective sound is nevertheless important. This is my personal hi-fi as well as a reviewing system, and it is something I want to enjoy listening to. Equally, if I don’t enjoy the sound of my reference system, I’m not going to enjoy reviewing products, and by extension, I’m not hearing the products I review at their best.

Reliability and build quality

Just as technical competency is important, so are reliability and build quality. My system sees a lot of use, often multiple hours a day. I have seen many components come and go because they simply were not up to the standards of reliability expected in any consumer hi-fi, let alone a reviewer’s reference system. I’ve seen kit fail due to cost-cutting in components, bad quality control in manufacturing and assembly and poor thermal design. I want a system that is dependable and low maintenance, with backup from the manufacturers or readily available service documentation should something go wrong.

Features and Functionality

I don’t entirely believe in the audiophile approach to minimalism. I don’t agree, for example, that adding tone controls to an amplifier comes at such a significant cost as to reduce the quality of the amplifier by any appreciable degree if implemented properly. The number of tone-shaping circuits a recorded audio signal goes through before the final master is enough to make any audiophile cringe. When I buy a system, I want the components to work in harmony but I also expect a few conveniences. A decent remote control, for example, 12-volt power triggering or extensive connectivity. I’m not going to pay huge sums of money based only on a brand’s reputation for a component so simple that manufacturing costs are negligible and the retail margins are through the roof.

All of my previous components fit the above criteria. However, the PM-11S3 being an integrated amp, was at times difficult to integrate with other components. I therefore decided to re-evaluate the system as a whole, and in doing so take the opportunity to detail the system that will now be used for Audio Appraisal reviews going forward.

I knew I wanted a pre/power setup. This is by far the most flexible configuration of components and is a setup I enjoyed greatly a few years ago before I switched back to an integrated amp for reasons of convenience and constrained space. I needed a versatile preamplifier with balanced and single-ended inputs and the highest quality volume control possible. I wanted a hefty power amplifier yet one which is relatively compact. I wanted some dedicated headphone amplification to power an increasing collection of cans for private listening. I need a phono stage to accommodate all cartridges. A DAC to handle digital duties, with a decent CD transport. I wanted a streamer, similar to what I am currently using but with the added benefit of Chromecast and AirPlay 2. And one of the best vinyl front-ends available at any cost. I eventually settled on a system that meets all of my needs, now and (hopefully) long into the future.

Amplification

Aa System M8 Pre

Having been a fan of their recently reviewed M2 range, I opted for amplification from Musical Fidelity. The M8s Preamplifier is the company’s flagship solid-state preamplifier, sitting below the Nu-Vista in their range. It has 2 balanced and 5 single-ended inputs with a fully configured tape loop, home theatre bypass and plenty of output options with the ability to drive any power amplifier over any length of cable. It incorporates a precision volume control with essentially perfect tracking and is one of the best measuring preamplifiers in the business.

Aa System M6 Prx

I paired this with the Musical Fidelity M6sPRX. This is a 230W per channel dual-mono power amplifier with a peak current delivery of 140 amps and vanishingly low levels of noise and distortion. I considered a stack of Hypex NC400 class D monoblocks, eventually discounting them due in part to questions as to the reliability of the switching power supplies, and to the need to create custom bridged versions to produce a configuration with enough power, which still can’t equal the current delivery of the M6sPRX. I also consider the stereo and mono amplifiers in the M8s range, but given the size of the room I don’t need the extra power nor the additional power draw from the wall and cost constraints sealed the deal. The M6 PRX will comfortably drive just about any speaker to high levels without strain or distortion, and is measurably and sonically neutral.

Headphone amplification comes courtesy of Pro-Ject’s Head Box DS2B. This is a fully balanced, dual-mono design based around TPA6120A output amplifiers, extensively regulated power circuitry and phase inversion for the single-ended inputs. The included power supply is a cheap, lightweight and poorly specced universal wall adapter with below average performance so I built my own. It’s still a switching PSU, but with regulation to within 1%, better RF immunity, minimal RF leakage, more headroom and double the output current capability of the included adapter. This dropped the noise floor considerably and completely transformed the sound of the Head Box to a level I hadn’t expected.

Digital

Aa System Head And Dac

The DAC again comes from Musical Fidelity. The M6sDAC is a fully balanced DAC with plenty of digital inputs, asynchronous USB, fixed and variable outputs in both single-ended and balanced and even a quality headphone amp onboard. It measures exceptionally well with four 32-bit ESS Technologies DACs in dual-differential mode providing class-leading noise and distortion figures. It sounds sublime.

The streamer is from Cambridge Audio. The CXN V2 may seem a downgrade from the 851N – and in terms of its analogue output it certainly is. Here however It is used simply as a transport to feed the M6sDAC, and unlike the 851N features the latest iteration of Cambridge’s Stream Magic platform and should therefore see support for the latest features for some time into the future. Again it measures well, and given the re-clocking capabilities of the M6sDAC, it is as good a digital audio source as is needed.

Aa System Cxn And Cd

The CD transport is also from Cambridge Audio. The CXC is a bargain transport with an accurate digital servo and thus a highly accurate digital output. Also fed into the M6sDAC, it makes CDs sound quite remarkable. I don’t play CDs very often these days, and given the objective measurements from the CXC’s digital output, I doubt that a better transport would make a shred of difference. It is something I will try, but the CXC looks nice in the rack so it’s staying – for now.

Vinyl

Aa System Technics Sl 1200g

The vinyl front-end will come as no surprise to regular Audio Appraisal readers. The Technics SL-1200G is one of the best turntables around at any price, primarily owing to its class-leading drive system and gimballed magnesium tonearm. It is beautifully engineered, sounds sublime and so it holds its position on the top of the rack.

On the end of the arm is an AT33PTG / II. I love this cartridge and still think it’s worth every penny even despite a recent price hike. I may at some point try the new OC9X with its special line contact stylus, having been impressed by the VM760SLC. Quiet in the groove, with plenty of detail and not a hint of distortion or sibilance, the AT33PTG/II is a great sonic match for the Technics.

I use a Vinyl Passion Dustbuster to keep all styli, including those that come in for review, spotlessly clean. This gives us the best sonics and extends stylus life.

We also have available the AAP12 and Project Maple, two of our recent builds. The former is presently fitted with an Audio-Technics AT-VM95ML, and the latter a classic AT95E.

The phono stage is the Musical Fidelity M6 Vinyl. It features 3 inputs, all of which are selectable between moving magnet and moving coil, with independently configurable loading for each. It’s also fully balanced and is one of the quietest phono stages on the market today with the added advantage that it is practically impossible to overload, and thus produces a sound that is clean and clear of any distortion.

Aa System M6 Vinyl

Cabling and Ancillaries

Cables are a mix of pro-grade balanced XLR leads with combinations of Comus and Sommer cable and Neutrik plugs. My thanks to Designacable for supplying the latter, more specifically Sommer Carbokab balanced cable and the industry-standard Neutrik NC3FXX and NC3MXX plugs. You can purchase this cable Here.

The single-ended cables are a mix of Sommer Onyx 2025 and the Van Damme UPLC-OFC twin interconnect, again with Neutrik plugs. The speaker cables are Van Damme UPLC-OFC 6 mm squared, and the bi-wire links are 6 mm squared Summor Meridian. The CXC and CXN are connected to the M6sDAC via Hosa DRA-501 75 ohm coaxial leads.

Massive thanks to LucaSoundVision for supplying the Van Damme cables for this system. They supply a huge range of terminated and unterminated cables from a range of manufacturers, but with an excellent range of Van Damme cables in particular. The cables are beautifully made and terminated with AIRLOC plugs and finished with heatshrink. You can view their products on their Website or the LSV Cables eBay Shop.

Power cabling comprises standard earthed and 13A fused IEC C13 cables, with a C7 supplying the cassette deck. Most are three-core, 1.5 mm conductors, though a cable comprising 4 mm conductors powers the M6sPRX. Power distribution is via ordinary power strips with unobtrusive surge protection. All cable lines are tied behind the rack with power and interconnect cables separated from one another.

The system stands on the Lack Rack . Despite its extremely modest price, this rack of modified Ikea side tables remains one of the best racks I’ve owned. It’s lightweight, extremely rigid and resistant to external vibration while being deep enough to hold just about any component and take the weight of the system. Fitting the new system necessitated adding a few more shelves. While I was at it I refilled the legs with tighter-fitting timbers and added a pair of fans behind the amplifier as space around the amp is more constrained than is ideal.

Aa System Tape Deck

Additional components include a Technics RS-B665 cassette deck. A custom trigger controller switches AC power to a standard power bar, providing outlets switched by the 12V trigger output of the M8s preamp.

Speakers

I have yet to mention the speakers. As of the time of writing (October 2019) the speakers are undergoing a change. In the beginning I used Tannoy Precision 6.2s and latterly Tannoy DC8Tis and DC10s which are currently in use. I’m looking at various options, including a DIY design with top of the line Volt drivers and custom cabinets. I am also interested in models from Fyne Audio, which being a Tannoy fan are right up my street.

And of course, new Tannoys certainly haven’t been discounted. The speakers will have the most significant influence on the sound and must be chosen wisely, especially when reviewing components. The loudspeakers must fit the room in which they are used and in this case must work in perfect harmony with the system and produce a neutral response, as free from colour and imparting as little of their own character as possible. There are limits, of course, this being a hi-fi in a domestic environment. The room is not, and will never be perfectly treated, and listening enjoyment is a foremost consideration, but a compromise can always be reached. I will update this article once a decision has been made.

Our current crop of headphones include the Meze Audio 99 Classic, the ATH-M20X and ATH-M50X from Audio-Technica, Edifier’s H850 and H880,and some models from Sennheiser and AKG among others.

Aa System Full Rack

And that’s it. That’s my hi-fi. That’s the new reference system, which will hopefully see us through the next few years and beyond. This post will be updated to reflect future changes and kept as a historic reference to log the equipment used to create these reviews. This post was first published in October of 2019 and was last updated in December of 2019.


About Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2

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