The Shanling - UP4 unit delivered to me has significant channel imbalance: the right channel output is much less than the left one. I had to return it to you for a replacement. I assume that you have professional equipment able to accurately measure and quantify individual channel outputs, demonstrating the defect quickly and conclusively.

Once the problem was identified, the UP4 device was thoroughly examined and its sound output was exhaustively compared with similar hardware, namely, Fiio BTR5 and Shanling's own UP2.

SOURCE USED:
1) Microsoft Surface Laptop 3
2) Pioneer External Blu-ray Writer
3) Richard Strauss: Elektra Blu-ray with DTS-HD Master Audio 96 kHz/24-bit
4) Various 24-bit/192 kHz FLAC files

The UP4 device has a very noticeable sound output difference between the channels, readily identifiable even by a casual listener. The left channel sound output is about 30% louder than the right channel. The device has been tested over many hours of listening paired with several IEMs, over-ears and on-ears. None of my other bluetooth/desktop DACs suffer from this defect.

I am disappointed in Shanling but trust you to take care of the problem by replacing the malfunctioning device. Eagerly waiting to hear from you.

I received the unit from headphone zone within 48 hours, full marks to them for that at least. The story thereafter took a turn for the worse though.

I ordered this unit as a birthday gift to myself and was really excited when I received it within 2 days of ordering. I immediately wanted to try it out so after I read the manual and the website I paired my phone (Asus ROG II) to this unit to give it a spin. I listened to music over Spotify and USB Audio player Pro and wasn't too impressed with the output of the FLAC files compared till I turned on the dual-dac mode. That kind of opened up the soundstage a bit and increased the separation between the instruments. I think the BT 5 iny phone definitely helped when paired to this unit. I haven't got a chance to measure the battery life yet but it aes impressive considering I had to charge it after 3 days of continuous listening.

Now comes the disappointing part, the wired (USB-C) connectivity with phones. I tried it with a Xiaomi Mi A1, Asus ROG II andy laptop. I used the cable supplied with the unit and even a Smart Smith USB 3 Gen 2 (10gbps certified) cable but it just refused to work. My Xiaomi Mi A1 and laptop recognised the shanling and allowed me to manually route audio through it. It showed the shanling selected but no sound came out of the earphones.

I immediately decided to report this to headphone zone and opted for the 7-day return policy but no matter what I tried the website threw up an error saying I could only a aio of this option within 7 days of ( I purchased this device on 5 Oct, it was delivered on 7 Oct and this case was logged on 7 Oct itself). Extremely disappointed with this. I will definitely be more careful purchasing stuff going forward.

First of all thanks to headphonezone for promptly allowing me to upgrade my order from UP2 to UP4. They were very fast and accommodative and the gadget reached me on the third day.
About the device, its small and versatile. Supports a lot of codecs for listening to High-Res files. Sounds deep and crisp but smooth. Mid range is also clear. Overall experience is smooth and non fatiguing. One good thing is that it updated its firmware in OTA through Shanling app indicating that it is from a newly manufactured lot (as earlier versions do not update over OTA as gathered from the net). Now its running on V1. 3. The connectivity is fast and it can remember connections with 2 BT devices.
The app is a bit amateurish. When connected it shows a DISCONNECTED(when actually it is connected) button which should read DISCONNECT actually. BT codecs are chooseable and is only limited by the transmitting device. I used with my LG V20 and POCO F1 with LG sounding smoother and POCO with a little more shimmering highs. Enjoyed on both. Adequate power to drive my AKG K712 pro through unbalanced out.
I need to buy a balanced cable now for my detachable earphones. Planning to make a DIY one as balanced cable are costly.
Can anybody confirm the 2.5mm configuration for Shanling. What I gathered from net is R-, R+, L+, L- for TRRS pins respectively.
Regards
Partha

This is my first audiophile product and I'm really loving it. Tried using through various sources like Laptop, Android & I Phone and it's working great with all the devices. Sound out put is best when connected through Ldac codec mode

Well, at first I didn't trust headphonezone. I've ordered on 13th. But surprisingly it got delivered on 15th. From that day I'm listening to this. And trust me , it's awesome . I wanted less bassy, more crispy, focused vocal. I get that without eq ing . I'm listening in my android with LDAC codec and with my windows PC using the USB DAC. I've paired it with HIFIMAN HE400SE, which is a planar magnetic headphones. We know that a planar magnetic headphone is not easy to drive. But Shanling UP4 can beautifully do its job. Although , You can't use USB DAC thing with your smartphone (at least Samsung m51), as one of headphone gurus said to me that some smartphones are not compatible . Anyway, with apple music and yt music , I'm having a fantastic listening experience. Currently I'm using the unbalanced cable with UP4 , but in future I'll definitely taste sound using balanced cable and UP4.

With headphone jacks disappearing from smartphones, and Bluetooth earphones still nowhere close to wired headphones in terms of audio quality, I wanted something that turns wired earphones into wireless ones without sacrificing quality and driving power. It means that I wanted a Bluetooth adapter with LDAC codec, high-quality DAC, and a powerful amplifier that can drive even bigger headphones. The Shanling UP4 was along the most high-end portable Bluetooth adapter in the market, complete with AAC, aptX, aptX LL, aptX HD, LDAC, dual-DAC chips from ESS, Hi-Res certification, NFC, and long battery life. After using them for a week, here are my thoughts:

Pros:
1. Very good connection stability and range.
2. Presence of all wireless audio codecs: SBC, AAC, aptX, aptX LL, aptX HD, and LDAC.
3. Excellent audio quality, at least as far as wireless audio goes.
4. High amplification power.
5. 3.5mm unbalanced and 2.5mm balanced ports.
5. Long battery life (more than 10 hours on a single charge at high volume levels).
6. NFC for quick connections.
7. Status LED shows which codec is being used.
8. Smartphone companion app and support for firmware updates.
9. USB Type-C port with fast charging.

Cons:
1. Smartphone app is garbage. There's no volume level adjustment from the app, and it sometimes says that the UP4 is not connected to the phone even if it is.
2. Glossy gass body can gey scratched. Could've had a metal design or a matte glass finish.
3. Should've had a display (to show active codec, battery level, and audio source) for this price.

I bought my Shanling UP 4, my first ever AMP/DAC (with Bluetooth). I have paired it with my shiny new TinFi T2 . The sound separation is mind blowing (at least to me) for the budget. The Shanling Up 4 has ample amount of amplification for my drivers and for my needs too. It has also other fancy stuff like a 2.5 mm port for balanced output and some other things (that I have not used so far). Also the quality of the unit is very good.

I would recommend everyone, who is looking for a Dual DAC Bluetooth AMP, with incredible track separation and well balanced audio quality, in a decent budget - you can go for this.

Oh! and the shipping was very very fast, I got my unit in 2 days.