AKSA 55

The Aksa 55 is a solid state, push-pull power amplifier module delivering 55 watts RMS into an 8ohm load. Input sensitivity for 55W output into 8R is 548mV rms into a Zin of 47K.

Designed with sonics as the primary focus, the AKSA employs extremely refined circuit design and topology to produce a stunning sound quality rivaling the best audiophile grade amplifiers in the world.
This is realised in a module which, through meticulous industrial and engineering design, is nonetheless easy to construct and set up.

The result is a 75mm x 86mm (3" x 3 3/8") single-sided, solder-masked pcb with full overlay. All copper on the pcb is pre-tinned for easy assembly. The instructions run to 13,200 words and 36 photos and diagrams, and the AKSA can be assembled by people of moderate experience who are possessed of some soldering skill. A diagnostics section is included in the instructions for fault finding post-assembly should there be difficulties, with recourse to email support if necessary.

SPECIFICATIONS:

The AKSA family of audio amplifiers was developed to overcome most of the sonic problems of SS push pull technology, and incorporate some highly innovative thinking, not just dictated by the engineering (which is crucial) but heavily influenced by the subjective issues of listening to music.  Mindful of the engineering issues, the design cycle has also been focused on the audiophile listening experience, and the inspired desire to transfer human emotion via the artform of music.  The justification for this is simple;  people listen to music to be moved, not to marvel at the elegance of the amplifier design.

While engineering has been crucial in achieving the goal of the AKSA, the primary focus has remained the transference of emotion, and to a large degree conventional measurements have been downplayed.  In no way does this indicate that distortion measurements and slew rates are not important, but rather that there is more to this technology than first appears. 
The AKSA amplifiers create a presentation comparable to a quality tube amplifier, whilst delivering stunning resolution and a pure, sweet, musical sound.  This has been achieved at very low cost in an attempt to balance the pricing policies of high end audio.   Like many tube amplifiers, the AKSA 55 is best suited to quality speaker systems of 88dB/Watt/metre or higher, but the 100W amplifier shines with just about any loudspeaker system, regardless of efficiency.

The key features of all AKSA amplifiers are the utter absence of intermodulation, startling transients, crystalline clarity, and palpable depth of image.  These qualities conspire to give the AKSA extraordinary emotional communication of the music. This last feature is most unusual for solid-state amplifiers, and is normally reserved for tube amplifiers..

The amplifier is simple to build.  Both channels of the 55W amp are assembled on their own individual 3.4" x 2.95" (86mm x 75mm) printed circuit boards.  The 55W amp utilizes one single, ledged 300mm x 75mm heatsink for both channels, and uses dual mono 36V rails.  The AKSA amplifiers run very efficiently in Class AB with a quiescent current of 55mA per complementary pair, and deliver imaging, slam and clarity rivalling the best Class A designs but with none of the attendant thermal problems.

This amplifier has won accolades around the globe for its astonishing sonics, especially in North America and South East Asia. While the AKSA uses a time-honored topology tweaked and refined with state of the art components and painstaking dimensioning, it truly represents the pinnacle of development of modern day analogue amplification. The elegance and compactness of this jewel gives it stunning looks as well as performance, and the low cost guarantees it will be a top seller for decades to come.

A lower power version of this amplifier can be made which offers wonderful sonic qualities. In this case, the power supply rails are reduced from +/-36V to +/-24V, resulting in an amplifier of 25W rms power output into 8R. This variant of the AKSA is highly suited to efficient speakers of the type often used with SE tube amplifiers or active crossover systems. The AKSA 25W amplifiers is available at the same price on request.

The designer, Hugh R. Dean, an Australian with an eclectic background in education, computing and language training, stands behind his product with unsurpassed 24/7 email backup.

Build this amplifier, and join the growing cadre of blissful AKSA owners, many of whom go on to buy more amplifiers for multi-amp Home Theatre installations.

If you have any questions about the AKSA and are considering purchase, ask one of the owners! You can find them in the Aspen Amplifiers section at:

www.audiocircle.com

BUILDING THE AKSA:

WHAT'S INCLUDED?

The kitset comprises:

A pair of high grade PCBs, specification matched power output devices, all passive and active components, a premium quality, pre drilled and tapped heatsink, extensive and detailed instructions, and full support and backup for two hours of email time. Also supplied are four 4,700uF 63VW quality power supply capacitors, specialized ultrafast soft recovery diodes and a custom pcb to mount these large items and incorporate a star earth.

The heavy power transformers and the enclosure are are not supplied in the kitset.

More ASSEMBLY DETAILS can be found here

WHAT YOU HAVE TO SUPPLY:

There are a number of essential components that you need to supply. (Mostly these are large and heavy components that are impractical to ship around the world one at a time!)
Because the AKSA kitset has been concieved as "high end audio for everyone" the choices you make for these are dependent on your preferences and budget. We can offer some as options when you purchase. (See OPTIONS below)

YOU WILL NEED:

A case to mount the components in, connecters and wire, the two power supply transformers, an IEC power entry module for the mains plug, and two pairs of binding posts.

Tools and facilities:

A Workbench of some sort, A fine Soldering Iron, Long Nosed Pliers, fine Side Cutters, Multimeter, Reading Lamp, Philips Screwdriver, Moist Sponge, Sharp Razor, Jeweller's screwdriver, Superglue sachet, School compass.

SOURCES for other components can be found at CONTACT/SUPPLIERS

OPTIONS:

Nirvana upgrade kit (for ultra-performance):

This set of Premium Quality components has been selected after exhaustive listening tests. In accordance with our philosophy of affordable, DIY audio, these grade of components are not included in the regular kit because of their wholesale cost and sourcing difficulties.
By upgrading these sonically critical components, the AKSA amplifiers become not merely exceptional, but sublime.

PRICES:

The prices for all our products can be found at: BUYING/PRICELIST