CAAS Audio is dedicated to the technical advancement of ultimate high quality audio reproduction. Over the last decade our extensive and continuous R&D program has facilitated the development of the following unique technologies:
RWave - RF & Microwave Design Techniques
All CAAS Audio products have been developed using RWave techniques. RWave is an ultra wide bandwidth circuit topology that uses RF & Microwave circuit design, layout and stability techniques to provide superior signal path fidelity. RWave combines ultra fast transistors, DC coupled circuits, short signal paths, intelligent component placement and TZFB (True Zero Feedback) and CSD (Coupled Symmetric Drive) technologies to produce the ultimate high quality audio reproduction.
TZFB - True Zero Feedback
TZFB (True Zero Feedback) is used to remove any feedback loops and any performance and sound degradation associated with feedback loops such as increased Total Harmonic Distortion (THD), Inter-Modulation Distortion (IMD) and Transient Inter-modulation Distortion (TIM). All CAAS amplifier circuits utilise TZFB. CAAS amplifiers have NO Global feedback loops and NO Local feedback loops, the only type of gain control implemented is emitter degeneration.
CSD - Coupled Symmetric Drive
CAAS Audio's CSD (Coupled Symmetric Drive) topology allows bespoke zero feedback circuits to operate at high speed with very low distortion levels.
In our power amplifiers, the CSD input stage consists of a fully balanced symmetrical differential stage with a small voltage gain using ultra high linearity complementary transistor pairs, operating in class A mode with NO feedback just emitter degeneration. This stage drives a balanced symmetrical push pull voltage amplifier stage again operated in class A mode with NO feedback and a moderate voltage gain. Input stage current sources are coupled to our proprietary NIDS (non-intrusive DC servo) circuit. CSD is essentially two true zero feedback parallel complementary amplifiers operating together to increase bandwidth, speed and reduce THD, IMD and TIM.
In our pre-amplifiers, a single JFET gain stage incarnation of CSD is configured as a DC coupled, zero feedback current buffer offering extremely low THD, IMD and TIM, extremely high bandwidth and the cable and power amplifier drive capabilities that passive pre-amplifiers lack.
VPI - VAS Perfect Isolation
CAAS Audio's power amplifiers utilise a bespoke VPI (VAS (Voltage Amplifier Stage) Perfect Isolation) driver stage that drives the output stage transistors (several complementary pairs of high bandwidth transistors) biased heavily towards Class A and running open loop (NO feedback). VPI technology allows the output stage to be driven with zero loading of the voltage amplifier stage, irrespective of the load that the output stage is driving.
OpBias - Optimal Bias
An OpBias (Optimal Bias) system has been developed to bias the power amplifiers output stage for reduced power dissipation while maintaining maximum audio performance.
At normal listening levels the amplifier will always be running in Class A mode and deliver up to 20 watts of pure Class A power into an 8 ohm load. If extra power is required the amplifier will seamlessly move into Class A/B operation and deliver Class A/B power up to the amplifiers maximum rating.
This biasing technique results in lower power consumption, lower heat output and an extended component lifetime over that of a conventional Class A amplifier, while delivering superior performance.
NIDS - Non-Intrusive DC Servo System
NIDS (Non-Intrusive DC Servo) circuit has been developed to continuously fine tune the amplifier circuits, to maintain a very low DC output level without any negative effect on the sound performance. NIDS allows all DC levels to be kept at very low levels without interference with the audio signal. This has been achieved though intelligent component choice, bandwidth selection and by only fine tuning circuit current sources (at an ultra low sub sonic frequency). No correction signals are ever fed into the sensitive audio circuits.
iTrans - Intelligent Buffering & Low Jitter Data Transfer
All CAAS audio servers have been designed to produce the highest audio quality possible. In part this has been achieved through our custom 8 wire digital interface.
iTrans is a data buffering and ultra low jitter re-clocking technology that allows near perfect data re-clocking and bit perfect parallel line digital signal transfer. The iTrans transfer system allows vastly superior interfacing between the computer system with the parallel DACs, in comparison to standard S/PDIF or I2S interfaces.
HDAC - Hybrid Discrete Digital to Analogue Converter
Over 4 years of research and development into discrete matched passive R-2R DAC networks and ultra high precision LASER trimmed on wafer passive networks has resulted in a bespoke hybrid R-2R design that far exceeds any purely discrete matched network we have tested.
The CAAS HDAC consists of two Monaural, 16Bit ultra high precision LASER trimmed R-2R passive ladder DAC networks that are matched to an accuracy far beyond discrete matching and contained on a micro silicon wafer to eliminate the thermal gradient issues normally associated with discrete matched networks. These passive R-2R networks are then DC coupled to CAAS Audio's bespoke monaural True Zero Feedback (TZFB) class A discrete buffer stage to produce a DAC with unprecedented realism.
Fastpower - High Speed Discrete Regulated Power Supply
CAAS Audio amplifiers house six separate power supplies. Each channel has six Fastpower independent bespoke discrete regulated, very high speed, very low output impedance, high current delivery power supplies. Four for the voltage amplifier stages and two for the current amplifier output stage. These bespoke supplies are key to CAAS Audio's instantaneous current delivery system.
CAAS audio servers can be fitted with as many as fifteen Fastpower discrete regulated power supplies.
SRVC - Switched Resistor Volume Control
The CAAS pre-amp circuit consists of a bespoke 128 step, relay switched resistor volume control.
The front panel volume control only provides a reference voltage to the internal analogue to digital converter (ADC). This ADC feeds into the CAAS computer system which processes the data, reduces jitter and hysteresis and allows for remote control and LAN Networked device control. The CAAS computer system then controls a bank of high quality silver contact relays which switch different configurations of high precision, high quality metal film resistors to produce attenuation levels between -50dB and 0dB in 128 discrete steps. Although this is a vastly more complex system than the standard audio potentiometer, the sonic purity achieved far exceeds that of any potentiometer on the market.
SAM - Switched Amplifier Modules
SAM (Switched Amplifier Modules) is a CAAS Audio proprietary circuit topology that consists of many separate zero feedback, class A operating (with zero switching distortion), DC coupled amplifier modules. Each module can be switched in or out of the circuit, this unique topology allows the CAAS Pre-amp to intelligently configure the optimum amplifier circuit for the most direct and purest signal path possible for any input / output configuration.