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 Robert's many years of experience in both professional and the car audio industries where he used, repaired and built high power, high fidelity amplifiers almost every day. With these lessons well learned over 30 year, 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 High 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 one transistor is working at any given 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 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 output transistors are on at the same time. The more bias you add the better it sounds.
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 performance across a wide temperature range. This stability allows us to "dial in" much more bias than any 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 four-inch fan mounted in the center of the circuit board. The fan forces cool air in a cross flow pattern through the massive finned heat sink before exhausting 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 always perform as intended.
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.