KingRex

Audio Amplifier

Eulating Tube sound is our goal. Main product: Class T audio amplifier 1. T20 2. T20U Characteristics of Class T technology: Class T is a registered trademark of Tripath technology Inc. Class T does not use PWM but it isn't pure analog design eighter. The circuit path of a typical Tripath Class T amplifier stars with an input stage that provides analog input signal buffering. The output of this stage then goes through the Digital Power Processing algorithms that dodulate the input signal with a high frequency switching pattern. The proprietary DPP Technology has derived from predictive and adaptive algorithms used in tlelcommunication processors. The basic idea is to monitor and determine the best way to encode incoming signals with minimized interference; and then analyze and adapt the ouptut to maintain systm stability and signal integrity. In other words, the predictive and adaptive processing learns the characteristics of the output transistors and based on the input analog signals, switches the transistors with the exact right timing. Switching is done within high frequency domain(typecally varies between 100KHz and 1 MH) so that any issues can be corrected quickly before become audible. The final power ouptput stage and qualification logic drive the speaker through an external output filter, Tripath Class amplifiers hasve THD+N (total harmonic distortion plus noise) ofless than typically 0.08% over the full audible bandwidth of 20-20,000Hz and IHF-1M(high frequency intermodulation distortion) less than typically 0.04% and therefore delivers what often defined as"audiophile performance". At the same time, Class T provides power conversion efficiency of 80%to over 90%, which is equal to or better than Class D. Valve audio amplifier TL066

Pre-amplifier

KingRex Pre-AMP has a hybrid design that improves on conventional voltage amplifiers with discrete components and high-performance op amps. It features two sets of line inputs with auto-select. Main products : 1. PRE-AMP The key components include three pairs of Burr-Brown IC: OPA627 for pre-amplification (being a new generation FET(Difet)op amp, is recongnized for its low noise and high speed.), BUF634 for increasing and sustaining higher output current(BUF634 is not only a high speed op amp current booster, it also improves compatibility with power amp and loudspeakers), OPA177 for DC servo(OPA177 makes sure the op amp output is free of DC power, avoiding any chances of harming the power amp and the loudspeakers. It also has another advantage. It’s not necessary to use extra output coupling capacitors and that improves the sonic performance a lot) On the power supply front, KingRex PRE-AMP is equipped with an 8VA toroidal transformer and a pair of National LM317T voltage regulators, delivering 13V/0.3A DC current to the circuit board. The Secret weapon is the unique design- plug-in PCB, Diamond Buffer circuit, which is a transistor-based all discrete-component buffering circuit that fine-tunes the incoming audio signal for frequency extension, tonal accuracy, holographic imaging and warm, tube-like atmosphere. Diamond buffer PCB mounted on top of the lower-deck main board through multi-pin connection. The advantage is this design is detachable. 2. PREference pre-amplifier PREference, the second-generation pre-amplifier from KingRex, is a logical extension of the success store award-winning Preamp. Centered around high-quality op-amp and the diamond buffer highly praised for its musicality, a current booster has been added to the final output of the amplifier stage to enhance drivability. DC servo circuit has also been implemented to avoid unwanted audio signal loss due to coupling capacitors. Volume control is ALPS. Gain is user selectable with a choice 7,14,or 20dB. The result is accurate and perfect signal amplification, free from colouration and yet highly adaptable, the ideal for outputting to power amplifiers

DAC

Nowadays more and more PC user require better soundstage from PC system. However, the sound come from computer and soundcard is not dedicated enough, the annoying noise & distortion is hard to avoid an outboard digital to analog converter that receives digital signals through USB cable seems to be welcome solution. So KingRex build up one good solution for music lover- UD-01 (USB DAC). It turns mundane desktop and personal audio into exciting high-end performance(The DAC –characteristic architecture is built around Burr-Brown PCB2702E DAC chip which is dedicated two channel audio has large internal strong buffer to store up audio packets. Low pass filter: Burr-Brown OPA2604 acts as output stage preamp and taking out the residual digital garbage and turns the audio signal into more analogue sounding stream to guarantee sonic excellence. DC servo: Texas TL072 low noise JFET op amps assigned to DC servo circuit. Coupling capacitor is to avoid harmful sonic impairment.

Power supply unit

Reserved Power Supply unit products which specially designed for T20 and T20U 20W Class T audio amplifiers. These optional power supply units increase more value than only single Class T amplifier in sonic performance and dynamic range. PSU It features a 48VA toroidal transformer coupled to a full fledged regulatory circuit with eight audio grade NCC aluminum electrolytic capacitors: 5 x 2,200 uF at AC input stage and 3 x 4,700 uF at DC output stage. The PSU provides abundant reserve to meet the demand when low frequency transients draw on high-current voltage. To quote 6moons again: "When the PSUs were added to the pot, musicality thickened. There was more warm air filling up a more xpansive soundstage. Bass got deeper, the midrange urned proportionally more pronounced to ake the verall harmonics even richer." SLAP (Sealed Lead-Acid Battery Power Supply unit) The slightest demand, the greatest satisfaction What are the differences between switching power, linear power, and battery power? After introduction of the T20 series audio amplifier to the public, KingRex sought the next evolutionary step in onicexcellence while preserving the xisting value for our customers. Currently we provide two power supply solutions for our T 20 series amplifiers, a power adaptor(switching type) and a power supply unit – PSU (linear power type). We believe these two products match most audiophile demands because of their reasonable price and excellent quality but also they sound good. Nevertheless, to satisfy the highest level of audiophile expectation for low noise and distortion, we have developed a pure power source – the SLAP (Sealed Lead-Acid battery power supply unit)

Speakers

Full range speakers ~ designated by JohnBlue Single-driver loudspeakers. Most people call them full-range loudspeakers since they attempt to cover the entire audible frequency spectrum with just one drive unit. Our editor prefers to call them widebanders. That actually reflects the technical reality more accurately since most full-range drivers can't cover the full frequency range.The character which all audiophile knows which could provide the most solid signal from the sources. Most of them all possess their own speical charm of the sound. JohnBlue's Bookshelf speakers : 3" - JB3 4" - JB4 8" - JB8B JohnBlue's Floorstand speaker: 8" - JB8F