EarStudio ES100 MK2-24bit Portable High-Resolution Bluetooth Receiver/USB DAC/Headphone Amp with LDAC, aptX HD, aptX, AAC (3.5mm Unbalanced & 2.5mm Balanced Output)

Updates on the BottomI just wanted to add a quick review for now because I think this little device is fantastic and it’s a shame that more people don’t know about it. I will give it 5 stars for my first impression but will continue to update this review as I spend more time testing it.I have been looking for a Bluetooth solution like this for a while now and I had never heard of this company or this product before. Even after finding it on Amazon and seeing the impressive spec sheet, I was very skeptical that it was legitimate. What finally convinced me to give it a try was finding forums on it and seeing people’s experiences with it as well as seeing a strong presence from the company in the form of a representative from the company thoroughly answering questions.Although I’ve seen many pictures and the promotional video about this I wasn’t prepared for how small and lightweight this would be. The device looks very nice and has a simple but functional layout. One button to power on, power off, put into pairing, play, and pause. It also has a volume rocker and a back/next track rocker that is also used to turn on ambient mode. It was very easy to connect to my iPhone and get it up and running straight out of the box in a minute.I don’t want to get too much into sound, battery life, or the app because I haven’t had enough time to test any of them very much. I will say that it does sound great using the 3.5mm jack and AAC codec and I threw a wide variety of music at it. Previously the V-Moda Bluetooth was some of the best I’ve ever heard but I would say so far that this is noticeably better for me.The unit had 75% battery and while I haven’t tested to see if any firmware updates fix a battery issue, the app seems to show the battery life while the battery notification on my iPhone always shows 100%. I used it for an hour on 3.5mm high performance and it took me to 70%. I don’t think this is any real indication of battery life but will try to test it going forward in an update to this review.The app so far is fully featured and I added pictures of the app in this review. With only limited time in the app I will say that I really like the equalizer and the fact that it has a healthy amount of presets as well as what looks like customizable and savable presets but I will test this out more soon. I also briefly tried out the ambient mode and thought it was a very neat feature with a surprising amount of features. I don’t know how much I would personally use it but enjoyed playing with it and found the implementation well done.So far I have only tried it on two of my many headphones but it was a pretty wide range with the IE80S and the HD800S. While I expected it to drive the IE80S without a problem I didn’t expect it to drive the HD800S so well. To think I got that sound quality out of Bluetooth from my iPhone is just amazing and I do see a lot of potential to use my headphones with the ES100.It is a little too early to give any recommendation other than people should take notice of this little device because so far it is very impressive. I will continue to test the ES100 and update my review after a lot more use but if it holds up, I can definitely say it will be a deal at $100.[UPDATE]I’ve still only used this for a couple of days but I am very impressed with the sound this puts out. I’m using the balanced output now and it is hard to believe that this is Bluetooth.I’ve also tried to test the battery and although the battery indicator seems to be buggy, if it is anywhere near accurate the 14 hour estimation of battery life could be very accurate and that is with EQ on, volume at 50%, and using the 2.5 balanced output.[UPDATE 2}There has been a firmware update that seems to have addressed the battery life indicator issue.The ES100 has been working amazingly and it is still impressive how good the quality of the audio is. If I had to change anything about the ES100 it would be with the placement and style of the controls. They do work well but they could be a little better and easier to locate and press without looking. Overall this is a great device and is a must have for people looking for something like this.

First of all, I own almost every amp designed to be on-the-go that can also take phone calls. Soundblaster E3, E5, FiiO's new BTR1 or whatever, and even other Chinese brands. This one blows each one out of the water completely! Mic quality is great. The app can adjust the EQ and a ton of other stuff, and it has never been glitchy for me.I can also use it as a USB DAC with my PC. Right now, I have it plugged into my PC via USB while AT THE SAME TIME having it connected to my phone via strong bluetooth connection. I can easily jam on my PC with a good DAC while not having to take everything off and answer calls. I can't tell you how long I've waited for this solution to work flawlessly; decade at least. ES100 FINALLY does it. This thing is a keeper. I wish that updating firmware was easier, though. Maybe through the App, but instead you have to manually force the download by connecting to a PC (not a Mac).Music sounds punchy and visceral, just like its hard-wired, but through bluetooth. I've purchased a 2.5mm balanced cable in order to see if I notice any differences.Anyways, at $99, this is a steal. Should be $199 with the performance I've encountered so far. it fills a very big void in this market, and I look forward to buying any future versions they come out with!ONLY CONS: If your headphone cables have a microphone on them, this amp will not work. Must be audio-only cables.Packaging: leaves something to be desired. But, I thought maybe that just means that they put all their money towards the PRODUCT development, and didn't leave any left for packaging. Of course, it could also mean that they were just cheap on everything! However, one listen to the device and you can tell it was not the case of the latter. This product works well and is gem, in my opinion.2018-7-4 Update:This still works good as new. It is my most frequently used Bluetooth. I pair it most often with my AAW W500 or Campfire Dorado. Firmware updates have brought improvements and new features, including Ambient awareness with a push of a button; helpful if you need to be aware of your surroundings. Still the best in its class.I also highly recommend getting one of these Earphone Wrap Cord Organizer - Cord Management - https://www.amazon.com/dp/B075K4KDY3/ref=cm_sw_r_cp_api_FRxpBbMBKP2Q8And it makes it easy to use all day. I also want to add that I still have never had any complaints about phone call quality or picking up too much background noise.