KingRex T20U integrated amp with USB digital processor and MKII PSU


The keystone or cornerstone is the central or supporting element around which a system, a doctrine, a school, a series of events revolves.

KingRex was founded in Taipei in the 80’s as a company specialized in LCDs, electronics devices and components for entertainment gears. Then, it specialized in information technology of high quality and, later on, in high-fidelity products on the cheap.

Included in its current catalogue, together with DACs and hi-fi amplifiers, there are several accessories dedicated to computer and audiophile users so to help them improving their listening standards in terms of quality.

Besides, the catalogue includes three series of wideband one-way speakers of various sizes. I hope having the chance to test and measure a pair of these loudspeakers.


Today we will review a new amplifier: the KingRex T20U and its partnering power supply unit (sold separately), the PSU MKII, which promises to make it reach primacy in the listening quality whether compared to the standard switching PSU.

The integrated amp introduces itself boasting a good sound, a black livery, a satin finish front panel, a well-finished aluminium volume knob in the centre of its fascia and a blue LED when it is operational.

Under its bonnet, we find a class-T amplifier and, hear ye, a DAC too. Yes, that is right. It is a “pay one, take two”: a great thing if you feel disoriented when you have to choose the best component to listen to your favourite streaming music. On the back we find the outputs for the loudspeakers whit 3,5 banana pins and the USB interface with dedicated toggle switch for the DAC mode.


The T20 equips the Tripath TA 2020 chip assisted by its heatsink while, on the right side of the circuit, towers the Burr-Brown PCM2702E DAC, which is famous for its qualitative skills. What can I say? A great match. For the operability of the DAC the frequencies officially stated are comprised between 32, 44,1 or 48 kHz, always at 16 bits.

The inputs are operated by Bennic MKP capacitors (metallic polypropylene, Ed.) consistent with the costs of the amplifier. The power supply is about 20 W per channel into 4 Ohms and 13 W per channel into 8 Ohms with a 99 dB dynamic range: enough power for high efficiency loudspeakers – also for the King Rex – which can be also used as loudspeakers for the PC. If you like, there are many upgrading possibilities but, if and when you want to modify something, remember that the guarantee expires.

The other components lay on a well-engineered big motherboard in order to keep performances and reliability in time ahead.

The partnering PSU MKII is similar in the manufacture and in the look. They can be piled if you like an audiophile touch.

The PSU MKII, once opened, shows a huge 48 VA toroidal transformer and five 2200 uF capacitors on the AC side of the circuit, with 3 x 4700 uF bolstering the DC stage. The performances of the T20U are always at best in whatever condition of use.


The listening experience

I have tested the KingRex T20U both with the standard switching PSU and the partnering PSU MKII. I used my reference system suitable of different set-ups, both in terms of amp loading and for its intrinsic quality, which I know quite well.

First test with: Denon DV 1500 modified DVD player and Sony CDP-XA50ES player, a pair of loudspeakers based on D’Appolito system with Vifa and Seas components, Infinity 9K A big loudspeaker system (and very important in terms of loading and driving), DIY cables and YYW-Premium Cable and Xindak FS-GOLD power cables.

Finally, I connected the T20U both as external DAC and as sound card to a last generation Sony laptop also predisposed for streaming music.


I started with some instrumental music just to get the definition of the instruments and their fundamental component. After that, I played from acoustic music and voices, to classical music, hard rock – making my son happy – and more intense jazz (making me happy). The playback has not given back unpleasant surprises. The sound was catchy and bright. Fine the extent between instruments and height. Maybe a bit of more bass would not hurt, but with the succession of the listening it turns out to be not so important. Good the depth of the scene, which defines itself by facing a virtual stage where you feel like seating in the first row.

With the PSU MKII, I have noticed a certain definition and body together with a better dynamics and noise reduction in comparison with the performances of the standard power supply unit. That has to be taken into account in order to get the best performances.

Its parent device, the T-Amp, when realized, was considered a giantkiller. Therefore, I have decided to connect the T20U to my reference loudspeakers, the Infinity 9K A: two staggering monoliths.

The performance has been great, of course, but do not expect the pressure and the stability of a power amp hundred times bigger. Nevertheless, it can gladden your evenings and summer nights without the heat of those huge electronics that are usually required to move these juggernauts.


As last test, I have connected my PC and downloaded the software. Also with streaming music at high definition, the T20U has performed like the top of the class. Considering the experience of the company, which aims to the best outcome at a little cost, we can say it has reached its goal by offering reliable products with great interface and listening skills.

I have listened to lots of streaming music thanks to the software at my disposal, like Foobar media player.


After several hours and days of listening and after having taken it to the clipping limit, my only complaint is about the headphone output and the remote controlling of the amplifier. Probably the designer’s mind was to use it for multimedia purposes, therefore at hand close to the desktop or laptop. And probably a slight audiophile inspiration has pushed him to put to the extreme this great amplifier with a separate power supply unit and a great layout. I want to stress the fact that I took to the limit the devices with exaggerate volume levels facing the neighbours’ protest.

The KingRex T20U and the PSU MKII have driven my D’Appolito system with nonchalance and the Infinity big monoliths with quite a compelling strength. With all their limits, obviously, but with all due respect to the music that was reproduced with extreme easiness, like a real audiophile amp. So to say…I am here too!

The fact of having at disposal an integrated DAC is also important considering the big success of the streaming music in all the audio meetings all over Italy: the real future, in terms of quality and fruition and also of accessibility and diffusion.

At the end, I have to take a step backwards because I have changed idea about the impossible match between High Fidelity and simple audio multimediality: together they have made giant steps and these gears bear out confirmation. In fact, a device does not perform worse or better than another one. It only needs the best conditions to play at best with the right premises.



I feel like proposing you this amplifier as computer amp or as accessory for your hi-fi chain, as a DAC connected to a laptop, to listen to high definition streaming music, or as an amp connected to a CD player. I am sure you will not be disappointed and, mostly if matched with the PSU MKII, it can give you hours of good high fidelity music. The price is more than competitive and with a small amount of money, you could move your first step into the multimedia audio world and into the hi-fi world wearing your slippers…. Unfortunately, it is no longer in my listening room. I was getting used to it… enjoy your listening.


Official technical specifications:


TRIPATH power module TA2020-20

0.03% THD+N@10W 4Ohms

0.1% THD+N@12W 4Ohms

0.18% IHF-IM@1W 4Ohms

Power output:

22W @ 4Ohms

10%THD+N, VDD=13.5V

13W @ 8Ohms

10% THD+N, VDD=13.5V


88% @12W 8Ohms

81% @20W 4Ohms

Dynamic Range: 99dB

Over current and over temperature protection

Gold RCA and SP terminals

6mm thick aluminium faceplate and aluminium volume control

Noble potentiometer

Single USB input

DAC: Burr-Brown PCB2702E chips. Low pass filter: Burr-Brown OPA2604. DC Servo: Texas Instruments TL072 low noise JFET op amps

Dimensions: 180x45x140mm (WxHxD)

Weight: 2.1kg


Using 48VA toroidal transformer ensure maximum current output

Using transistor regulator circuit, 5x2,200uF at AC input stage and 3x4,700uF at DC output stage

Double fuse design: one DC fuse (in transformer), one AC fuse (inside on/off power switch)

Using NEUTRIK 3pin female jack and male plug

Build-in AC Line filter

Fully 6N FURUKAWA PCOCC interior wire setting


Official Italian dealer: to Audio Azimuth website

Official current price in Italy: T20U 299.00 EUR; PSU MKII 179.00 EUR

Associated equipment: to Mauro "OutliNero" Simolo system

by Mauro
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