Development and Technology Department
For dedicated audiophiles, high-end audio products are the tools that enable
the reproduction of music just as they envision it in their hearts, somewhat akinto what the musical instrument is to a musician. This means that sound quality isof course the most important aspect, but product design and operation feelingalso play an important role. While meeting such perceptual demands, every
high-end audio product is also a piece of electrical equipment for use in thehome, and as such has to meet strict requirements with regard to safety,reliability, and long-term stability.

■Design with full regard to safety
The safety of a product is the most important item to be considered at thedesign stage. Ever since introducing its first products in 1973, Accuphase has
always given careful thought to ensuring complete safety.
Based on international safety standards, we have developed our own designrules. Accuphase products are sold in more than 60 countries around the globe,
but rather than adjusting our products by destination, we apply only a single
stringent in-house standard that fulfills all international safety provisions. Thismeans that the most severe values for each safety item such as voltage
resistance rating and maximum current are fully met by all of our products,
thereby creating an ample safety margin.

1

■Developing superior circuits for electrical performance aswell as sound quality
The electrical characteristics
of audio equipment these days
are approaching the very limitsof measuring equipment. Some
audio manufacturers therefore
hold the opinion that once acertain level is met, electricalperformance no longer has abearing on sound quality.
Accuphase on the other hand
believes that electrical performance and sound quality are intricately related. In
our view, high-end audio equipment must excel in both aspects, combining
outstanding performance with impeccable sound.
Accuphase publishes the actual measurement data for its audio products,
such as distortion, noise and linearity, in catalogs and other reference materials.
Our specifications are not best-case, hard to reproduce numbers calculated
under special conditions in the laboratory. Rather, we give guaranteed figureswith plenty of margin that can be verified through measurement at any time. We
can do this because we have full confidence in the performance of our products.
Based on this approach, we have developed many innovative circuits thatpush electrical performance and sound quality to new heights, including the ultra
low noise volume control system AAVA (Accuphase Analog Vari-gain Amplifier),a current feedback amplification principle that ensures rock stable operation up
to the high frequency range, fully balanced instrumental amplifier topology, andthe MDSD D/A converter for accurate reproduction of Super Audio CDs.

2■Strict selection of parts and ample design marginsWhen building quality audio
equipment, the selection of the rightparts plays a crucial role. The failure
rate of individual parts will determine
the overall reliability and long-term
stability of the end product. We also
attach special importance to the"made in Japan" classification,
having decided to use only parts thatcome from a supplier with a manufacturing base in Japan or from an authorized
distributor in Japan who guarantees the quality of the product. Wherever
possible, we make direct visits to the respective company or plant where theparts are made, in order to verify their quality assurance framework first hand.
In using these parts, we design their operating conditions with ample
performance leeway, so that they can develop their optimum performance andreliability potential. For electronic components, plenty of margin is allowed in
aspects such as withstand voltage, rated current, and temperature rise, while formechanical components the margin applies to aspects such as mechanicalstrength and durability. The same principle applies to external design parts,
where beauty of the finish and the capability to withstand a variety ofenvironmental conditions is realized through many layers of plating, painting,and other surface treatment processes.
When quality parts are used with ample leeway, the structure of the unit itself
naturally becomes sturdy andmassive. This is especially true
with regard to the drive
mechanism of a CD player,
where the transmission ofinternal vibrations to the outside
is prevented by suitable
damping and the transmissionof external vibrations to theinside by vibration-proof
CD player vibration test
construction.
3

We even adhere to this concept when it comes to the box and packing
material for the product. Repeated drop tests under extremely severe conditions
were conducted to determine optimum materials and box construction. As aresult, the best quality cardboard available in Japan was selected for the double
wall exterior carton.

Temperature and humidity testing in anenvironmental Chamber

Product drop test

■Exquisite operation feel
In a high-end audio product, the operational feel of the controls is an importantconsideration as well. When designing thevolume knob and various switches, we devote
careful attention to the touch transmitted to thefingertips at the time of operation, and even to
the operation sound. Some of our products areequipped with custom-made rotary switches
combining excellent operation feel with highreliability, and with a special volume control mechanism made in-house.
Accuphase also fabricates proprietary
SA-CD/CD and CD drive mechanisms
in-house to micrometer level precision(one thousandth of a millimeter), toachieve ultra smooth movement of thedisc tray and quiet operation.
4

■Designed for impeccable soundElectronic parts and mechanical components as well as circuit topology andmechanical structure, all of these elements that constitute a piece of audio
equipment have their own sonic characteristics. This is the reason why audio
equipment from various manufacturers can differ considerably in how the finer
details and nuances of the music are reproduced. It is this type of soniccharacter that ultimately determines the value of the product. But even with thelatest measurement technology, it is very difficult to pinpoint or analyze soundquality differences. The ultimate measuring tools are still the human ears.
When embarking on the design of a product, we have a certain concept of thesound that we want to achieve, and this guides us in deciding on circuit topology,parts selection, and physical construction. But in many cases, it will not be
possible to realize the original sonic concept right away.
By changing the combination of parts, their physical layout, and various otherfactors, we adjust the sound and work towards bringing it closer to our goal. This
important process of sonic tuning is unique to quality audio equipment, it isusually not part of the development process for other electric products used in
the home. At Accuphase, about as much time is devoted to repeated listening
tests of our products as to technical development.
With automobiles and many home appliances, parts will often be swapped orchanges made to construction in the middle of a production run, with the aim of
reducing costs or improving performance. This practice is known as runningchange. Accuphase by contrast never does this, because a running change
would inevitably change the sound quality. We carefully preserve the single
prototype that was decisive in determining the sound quality of a given model
during development, andevery subsequent productis checked against thisreference, from very firstthat leaves our premises tothe end of the production
run, thereby ensuring thatsound quality remains
absolutely consistent.

5