The Deuce is the second of the two channels amplifiers which we manufacture. It is rated at 200watts continuous power per channel into 4 ohms and 400watts per channel into 2 ohms. The preamplifiers feature fully variable 24dB/Octave high (HP) and low pass (LP) crossovers with a range from 46Hz to 3.5KHz. A low frequency boost control allows for up to 18dB of boost at the centre frequency of 44Hz. The level control allows signals from 260mV to 8v to drive the amplifier to rated power. A selector switch does double duty for the amplifiers proper and the line output. In the flat mode both are fed full range signals. When in "Amp LP" the line output is fed the HP signal and when in "Amp HP" the line output is fed the LP signal. A "mode" switch allows for the complete bypass of the front end with the exception of the level control. Complete ground isolation is achieved through the use of our unique Balanced Differential Drive preamplifier. At present we offer the choice of two IC chipsets for the preamplifiers. The standard uses a low noise bipolar input style op-amp and the option is a BIFET Burr Brown chipset.

The main power amplifiers in The Deuce are fully complementary from input to output, they use temperature compensated constant current sources to drive the differential input transistors. This ensures that with varying temperature the DC conditions within the amplifier are kept constant. The inputs are fully balanced, using our Differential Drive circuit. The circuits employ substantial amounts of local feedback which allows us to use very little global feedback. Low THD was not our goal, rather sound quality. The output stages use high frequency B-ipolar output transistors. These have an Ft of 20MHz and are very linear with respect to gain. The Deuce has TEN 100 watt output transistors per channel. Zed has always been a strong proponent of having output stages vastly over rated. The reliability of the amplifier is improved when output devices are run at fractions of their capability. Using multiple lower powered output devices is superior to using single high powered devices. Please refer to the section under Techtalk Output Transistors.

The power supplies are fully regulated and there are no less than THREE separate sets of these. The main high current pair run the output stages, a regulated +/- 20v pair run the differential amplifiers and their associated constant current sources and the last pair which run from a completely separate transformer supply DC to the preamplifiers. This isolation assures minimum interference from one amplifying stage to the next. The main high current supply uses a bank of TEN 2,200mfd capacitors together with EIGHT ultra high current Mosefets as the main switching elements and the quad of high speed switching diodes, through a common mode choke, feed another bank of 18,800mfd for the main amplifier's supply. Since the power supply runs at about 60KHz this is ample capacitance to assure full power at 10Hz.

The mechanical parts were chosen for reliability and cosmetics. RCA sockets are solid gold plated machined brass types with teflon inserts. The power and speaker connectors are again solid gold plated machined brass types. The Power terminals accept up to #4 wire and the speaker #8.