PBN OLYMPIA AX

THE ULTIMATE IN SOUND REPRODUCTION

The PBN OLYMPIA AX is designed to exceed the very highest standards within high-end audio engineering and technology. The AX offers the most natural and unstrained musical reproduction attainable at present and for years to come. The PBN OLYMPIA AX is the ultimate in sound reproduction.

The PBN OLYMPIA AX, introduced in 2004 and enhanced in 2005, is the flagship model in the PBN OLYMPIA series. The PBN OLYMPIA AX weighs 93 kilos, due to its exceptional build quality. The AX features a powerful 4000 VA powersupply, 40 output devices and numerous Caddock resistors. The PBN OLYMPIA AX utilizes Teflon printcards only. The choice of components reflects the fact that the AX is a true non-compromise power amplifier.

A unique 75 ohms interconnect system is standard. The technical advantages and performance of this system is in a compeletely different league than any traditional XLR or RCA interconnect system, which by the way is also delivered as standard for the convenience of high compatibility.

The PBN OLYMPIA AX has a Fully Differential ALL-FET Design, which is vastly superior to any other transistor or tube amplifier technology. Of course, component matching and quality meet the very highest standards.

Only JFET and MOSFET devices are utilized, due to their proven superior sonic qualities.

The PBN OLYMPIA AX simply represents the highest performance attainable. The PBN OLYMPIA AX will handle any loudspeaker load with ease and brilliance, and without the slightest hint of compression or grain.

The PBN OLYMPIA AX is designed as a mono power amplifier, as well as a stereo amplifier. Either way you will get the same breathtaking sonic quality and resolution. The advantage of tremendous power overflow with 2 ea. PBN OLYMPIA AXs in a mono configuration should however not be under-estimated. It will extract even somewhat more of the heart and soul of music out of your recordings.

The cost-no-object PBN OLYMPIA AX is the definition of the illusion of musical realism. The AX practically equals the musical truth.

You will certainly not get any closer to the unfettered acoustic realism with current cutting-edge technology and engineering than this.

BOUND FOR SOUND'S COMPONENT OF MERITS / 2005

"PBN Audio 'Olympia AX' stereo/mono solid state power amplifier: $20,000 (+ Sales Tax)

Over two hundred pounds of power amp in a single chassis. It all starts with a single 4 kVA (!!!) transformer with 500,000 qF of power supply filtering and storage, and it finishes with 40 Toshiba MOSFET output devices. It's a beast to say the least!

Though only rated a 220 wpc, a figure eclipsed by many of the amps reviewed here over the years, the PBN was the obvious "King of the Hill" when it came to power on demand into any load. I think of this kind of power as locomotive-like... don't get in its way.

But this brute strength comes on without detriment to the sonics. I've never had any amplifier play as delicately and as sweetly, while still having the power in reserve to explode sweetly, while still having the power in reserve to explode with any crescendo found on tape, needle disc and CD.

I've also never had a power amp before that so completely made my speakers totally disappear. It was as if the music coalesced at the far end of the room and then flowered out toward the listening position. It's a step toward free form imaging; imaging from a system without audible ties to the speakers that create it.

Having heard this, you can take your 3 wpc girly amps, with their total lack of head room, and give them a pitch right out the door. It's this kind of power with a speaker with efficiency in the lower 90s that gives life to music. No matter what one thinks of low watt amps with high efficiency speakers, bass isn't cheap no matter what you think. It takes power to generate a room filling bottom octave, whether it be classical or rock. There is no free meal, and hornlike efficiency comes with a price - musical destruction.

It's a power amplifier such as this that restores the life and energy that is music."

Specifications:
Power 8 Ohms stereo: 2 X 220 W
Power 4 Ohms stereo: 2 X 440 W
Power 8 Ohms mono: 800 W
Power 4 Ohms mono:
Input impedance BNC: 75 Ohms BNC, with PBN OLYMPIA preamps only
Input impedance XLR: 2200 Ohms
Input impedance RCA: 100000 Ohm
Capacitance: 500000 uF
Power supply: 1 X 4000 VA
Total harmonic distortion: < 0,001 %
Dimensions: H 11" X W 19 X D 23"
Weight: 93 kg

MANUFACTURER PRODUCT INFORMATION:

The Olympia driver is an ALL-FET, high-speed driver circuit, intended for a 220 W Class-AB stereo power amplifier. With a maximum supply voltage of ±65V it can deliver close to 220 W into 8 Ohm and close to 400 W into 4 Ohm in Class-AB. Two PBN Olympia AX power amplifiers can easily be used as mono power amplifiers with a tremendous output capacity.

The Olympia ALL-FET driver circuit

The circuit is a fully complementary design, using only FETs as active elements. The input stage is a complementary differential Cascode FET circuit, using dual monolitic JFETs, cascoded first with low noise JFETs, and then with MOSFETs. Each of these is working with 2 mA drain current. The second stage consists of two JFETs in parallel and a MOSFET, connected in Cascode. The JFETs are operated at 10mA each, providing a total of 20mA drive for the output stage.

The bias circuit (Q18 and associated components) is a Vgs multiplier, using a MOSFET. The MOSFET itself, a TO-220 device, is selected according to the MOSFETs used in the output stage and is mounted on the output heatsink. This ensures proper bias tracking for the output MOSFETs. The output offset is tracked and controlled by Q11, which is a JFET-input opamp. Two shunt regulators provide ± 10V supply voltage for the opamp.

The L1||R33 parallel combination prevents oscillation when the load is highly capacitive (Exotic cables, for example!).

The feedback network is a so-called T-network, especially developed for the Olympia. It allows both unbalanced and balanced operation, without changing the feedback network. The only switching necessary is at the input, which equalizes the gain in unbalanced and balanced mode, and ensures equal input impedance for the two inputs in balanced mode (2.2k both)

The driver circuit is supplied from on-board discrete regulators.

ALL-FET discrete regulators

Each regulator is one half of a complementary power amplifier. Due to the high supply voltages, the regulators are using bipolar input and driver transistors and a MOSFET output stage. The reference voltage is provided by 6.9V low-noise buried-zener reference diodes, which are fed from JFET constant current sources. Output voltage can be adjusted between 45 and 65V. Minimum input/output voltage difference is 4V, but, to make sure that the regulator is always operating correctly, we recommend a difference of 5V. Absolute maximum input voltage is 73V.

Olympia CLASS-A/AB output stage

We have selected the Toshiba 2SK1530/2SJ201 MOS-FET for the output stage of the Olympia. These are matched to within 5mV VGS for each output stage half. Matching is performed at operating temperature (50'C) to ensure proper current sharing between the 10 MOS-FETs in each half of the output stage. There is a total of 40 output MOS-FETs in the Olympia's output stage, each device have a .1 µF film and foil capacitor mounted directly at the drain to ensure proper current delivery for unsurpassed micro dynamic capabilities of the amplifier.

The Output stage is mounted on the heatsink with Stainless steel bolts to minimize magnetic distortion within the devices. Main electrical connections are 8 gauge solid copper buss-bar strung between aluminum blocks with nylon inserts for electrical isolation.

Olympia Power Supply

The main power supply in the Olympia is centered around a MASSIVE 4.0 KVA transformer with separate windings for each output stage and for each driver stage, there is also a separate winding for "house-keeping". The transformer alone weighs an impressive 85 Lbs !

Four 60 Ampere discrete high-speed rectifier diodes are mounted on the main heat-sink for proper cooling . These Rectifies the AC power from the transformer to DC power. To ensure proper ripple current rejection 8 each high capacity capacitors are mounted in a special bracket on the bottom plate of the amplifier for a total of nearly 500000 µF. In addition 10 each 60 µF metalized polypropylene capacitors are utilized to ensure rapid current delivery to the output stage (2 in parallel and 1 in differential connection) as well as the driver stage (2 in parallel)

The Olympia Chassis

The Chassis is machined from ¼" aircraft grade aluminum to ensure proper mechanical strength of the amplifier. The chassis rests on 4 soft shoes for proper mechanical isolation.

WBT binding posts are utilized for speaker connections and there are Balanced, RCA as well as 75Ohm BNC input connectors on the back panel.