Get a good used Acopian, the show up on the Bay often. Buy Online SMSL AD18 Audio Digital Amplifier Bluetooth 4.2 USB DAC Amplifier Player DAC Hifi Power Amplifier 2.1Stereo Professional 80W Amp on Alitools. Your gonna need to spend some money for a good linear but its worth it. A picture of the board shows it can easily be unsoldered and 12-14 gauge good w ire can be soldered to the board then fed out the hole left from the coaxial Jack to connect to a good power supply. The AD18 probably isn't placed in the optimal spot for bluetooth range, but in my experience with other modern BT devices, it should be good enough to work throughout most of my 550 sq. SMSL SU-8S MQA DAC ES9068AS Bluetooth 5.
Coacial Jack's are generally rated at 5 Amos Max and are junky with minimal contact surface. SMSL AD18 80W2 CSR A64215 DSP HIFI Bluetooth Pure Digital Audio Amplifier Optical/Coaxial USB DAC Decoder With Remote Control Full Digital Power Amplifier 2.1 for Speaker. I'd also rather see two screws or binding posts for the 24V input. I haven't done any BT testing yet or compared digital inputs but I used optical two and it's nice. The headphone amp jumps in clarity and in every other possible way. A linear regulated power supply makes it not just play louder with less distortion but the HF looses the digital edginess and the image improves. We spent many hours on research and managed to find top 10 smsl ad18 that is best suitable for you. Get it Monday, November 15 - Thursday, November 18. It’s also built like a tank, which I love. SMSL AD18 HI-FI Audio Stereo Amplifier with Bluetooth 4.2 Supports Apt-X USB DSP Full Digital Power Amplifier for Speaker. It has just a little less power than the Topping amp, but in most use cases, you won’t miss the A90s additional headroom. Not only is the included supply underpowered it's a noisy switching ng power supply. At the end of the day, the 399 SMSL HO200 headphone amp is a worthy competitor to the Topping A90 if you need the same complement of connections and settings.
Upgrading the power supply should be considered a requirement.
This thing is flexible, nice looking, well built. SMSL Official Store has All Kinds of SMSL VMV A2 Power Amplifier 32bit 768kHz Support DSD512 Bluetooth UAT LDAC Aptx-HD AAC Subwoofer preoutput With Remote Control,SMSL AD18 HI-FI Audio Stereo Amplifier with Bluetooth 4.2 Supports Apt-X,USB DSP Full Digital Power 2.1 for Speaker,SMSL SA300 HiFi Power-Amplifier High Power Bluetooth 5. Nice value!! Very feature packed and nice looking!