Up for sale is an amazing piece of technology from QLS Audio in China.
This company has been making some incredible products over the past few years and the QA690 is their latest and greatest amplifier. It retails for $760 including shipping from China which is unbelievable considering the build and sound quality. I have been using it with a pair of monitors that retail for $11k in my two channel system and have been more than impressed.
I also owned the predecessor QA100 which was also a great sounding amp. The QA690 is in another league.
All you need to do is feed this fully digital amplifier a high quality usb signal with Tidal hi-fi and enjoy beautiful music.
9/10 condition with all original manufacturers packaging and remote control. It has been very gently broken in.
$600+shipping & Paypal fees. Save time and money from ordering a new one. I will pack safe and ship via FedEx ground to lower 48 US.
See below from manufacturers site for full details.
QA690 is a Hi-End Full Digital Stereo Amplifier, It is based on the QA100 with improvementon the circuit, We spent over 3 years on developing and continuing optimizationthrough testing more than 10 major hardware version. This is a true competitor to most of the Stereo Amplifier, complicated power supply systems and clock circuits.
Our target: “Perfectly and accurately recovery for the music recordings, and deep dark background”.
QA690 is able to drive 4Ω@160W-8Ω@100W2 way bookshelf and floor standing speakers smoothly with accurate, transparent, high dynamic range and excellent transient response sound style.
QA690 designed as open loop digital circuits, thus there is no stable problem even in driving speakers with very low impedance. Moreover DSP technology is employed to correct the expected deviation on the final outputs that made a significant improvement for the amplifier’s line output characteristics.
24bit/192KHz wav and DSD Support
QA690 supports up to 24Bit / 192KHz and DSD64 / 1Bit / Stereo (DoP input or USB) .
QA690(With USB) Also have a XMOS USB Bridge to Computer
The QA690 (With USB) also is have an asynchronous High Speed USB to digital audio interface that extracts the highest possible audio quality from computer audio sources.
The QA690 (With USB) is have High Speed USB 2.0 input data connection – Sampling rates up to 192 kHz and word lengths up to 24 Bit are supported.
Great care was taken in the design of the QA690(With USB) to isolate the noisy computer/USB environment from the digital audio output. The USB receiver and processing are powered by the computer, while the output line drivers are powered by a separate isolated linear power supply.
The QA690 (With USB) USB is designed to work with both Apple Macintosh and Windows PC computers. Microsoft Windows PC’s require the included Windows driver which works with Windows XP, Vista and Win7 / 8/ 10.
Features & Specification:
High quality sampling clock reform circuits.
Input: RCA Coaxial*2, Optical*1, Analog Line in*1, USB*1[Only for (QA690 with USB)]
Digital format: 16bit to 24bit, 32K to 192K Stereo (sampling rate and bit adaptive), DSD64(DoP input or USB)
Power Stage chip: TAS5624 *2
Master Volume: 0 ~ 80; L/R Volume Trim: -5 ~ +5; TREBLE Trim:0~5, BASS Trim:0~5 .
Use Low Jitter Crystal .
Total hamornic distortion (-2.5dBFS, 8 Ω) <0.02 %.
Dynamic Range, a-weighted 101 dB.
S/N ratio, a-weighted: 101dB.
Channel separation: 97dB.
Frequency response, audio range (20Hz - 20kHz) +/-0.5dB,8 Ω
Power: AC 90~120V and AC 200-240V selectable
Speaker Impedance range: 1.5Ω -16 Ω
Power output: 4 Ω 160W x 2CH; 8 Ω 100W x 2CH
Dimensions: 215mm x 315mm x 100mm
Weight: 5KG
