ARC AUDIO SE 4200 By Robert Zeff

Signature Edition by Robert Zeff is our no compromise, high power, audiophile amplifier designed and engineered by Robert Zeff and the staff at Nikola Engineering. This design is taken from Roberts many years of experience in both professional and the car audio industries where he daily used, repaired and built high power, high fidelity amplifiers. With these lessons well learned over 30 years he finally had the opportunity to make for ARC Audio the no compromise, no limits amplifier he had always dreamt of.

Signature Edition is a Hard Bias Class A/B amplifier. A simple Class B amplifier uses 2 output transistors to supply the current that moves the speaker. The positive transistor will push the woofer out and the negative will pull it back. In this design only 1 transistor is working at any give time. It is the transition between positive and negative that leads to the higher distortion that makes a Class B amplifier unacceptable for audio reproduction. In most cases a bias circuit is added to a Class B amplifier making it a Class A/B. The Bias circuit improves the distortion by slightly turning on the unused output device while current is flowing across the other. The more bias you add the lower the distortion but there is a side effect. Heat is created as the 2 output transistors are both on at the same time. The more bias you add the better it sounds but the more heat you produce but heat changes the natural bias of the output devices.

More heat equals more bias until you reach the point of over bias and the amplifier fails. The trick to the Signature Edition Bias circuit is managing the bias current at any temperature. By carefully matching the bias of every amp we are able to maintain stable bias across the temperature range allowing the technician "dial in" much more bias then a conventional class A/B amplifier. This is one of the key elements to the Signature Editions amazingly transparent sound.

The key to running so much bias is heat management. Signature Edition has a unique heat sink design that uses a 4" fan mounted in the center of the circuit board to force cool air in a cross flow pattern across a massive finned heat sink before exhausting it from the ends. This design minimizes the effects of installation location on the thermal performance of the amplifier. Mounted upside down, under or behind a seat or beneath a panel Signature Edition will perform equally well.

To further improve the dynamics and efficiency the Signature Edition amplifier exclusively use stiffly regulated, fully isolated power supplies. Regulation not only improves the damping factor and overall control of an amplifier but it eliminates any affect of voltage drops in the charging system may have.

◾ Audiophile sound quality based design
◾ Designed by Robert Zeff
◾ Class A/B switching design
◾ Microprocessor controlled design
◾ Microprocessor controlled Code based flashing diagnostics
◾ Concealed adjustment controls
◾ Open architecture adjustable crossovers on all channels HP/BP/LP/FP
◾ 12/24Db per octave selectable crossover slopes on all channels
◾ Internal chassis force cooled speed controlled fan for optimum cooling
◾ Hi/Low level balanced switchblade RCA inputs for maximum system integration
◾ RJ45 Ethernet input connections for true balanced input connections
◾ Block type terminal connections
◾ 256 color user selectable illumination circuit
◾ Combined Bias circuit and temperature regulation circuit to regulate bias and lower THD at any point in total thermal cycle
◾ Microprocessor high voltage power supply allows the amplifier to optimize power output at different ohm loads without the loss of efficiency or sound quality
◾ Vdrive based preamp stage improves efficiency lower internal signal loss
◾ Hand picked output devices used on all SE amplifiers.
4 Channels @ 4 ohms 110 Watts
4 Channels @ 2 ohms 200 Watts
2 Channels @ 4 ohms (Bridged) 400 Watts
2 Channels @ 2 ohms (Bridg