Thanks it does help but a noise free amp should be a minimal expectation for one's hard earned dollars. I've owned lots of inexpensive class D amps and beside an on/off pop with a couple all have been extremely quiet. If the one I ordered is noisy I'll send it back in a heartbeat.
I started this class D thread on AK seven years ago.
https://audiokarma.org/forums/index.php?threads/tpa-3116-vs-the-tripaths.574806/
I agree that a noise free operation should be an absolute minimum expectation today. However SMSL seems to be knocking out as many new models as it possibly can. There's a new Headphone amp and New DAC in the "8" series. The new "A" series, and the "9" series. The issue isn't the chips used as the chipset by infenion/Merius is extremely good, it's not even the application that is the problem, it's a question of their quality control which I cannot defend. Fortunately, in my particular case it was a matter of not bothering to apply thermal grease as only 20% in total of the 2 chips combined had any grease on them, and it was obviously hand applied, and never even spread. I dubbed my particular amplifier a Monday morning, or Friday Lunch time build. Tired workers, or exhausted workers not paying attention to small details. It is NOT an excuse, but it was in my case a very simple fix. I took the gamble to open mine because minus the noise that would change by moving the unit around while powered on, I had zero other sonic issues so I new the chips were ok, it was something internal that was assembly related that was the root of the problem. At $249, I don't expect much, but the noise was unacceptable, and again it was a very easy fix in my case. Did I forget to stress that my DA-9 after my intervention is dead quiet. As in ZERO noise coming from anything. The silence is literally pitch black, there is no noise no matter the brightness of the LED screen. The soundstage, scale is huge which is the really impressive thing about this amplifier. Most people who have a trouble free DA-9 all say the same thing, that the shape and size of the soundstage that the amplifier can produce is not something you can find in amplifier that cost many, many times more. It's great to introduce new products if the technology is truly new, and the sound is truly good and also have the Hi-Res label mean anything. If there is nothing above 20khz, then the amplifier doesn't comply to the Hi-Res standard yet they apply the silkscreen logo.
The TPA 3116 is not even close to what the Infenion/Merius chips can do as far as sound quality, though I do have a few 3116 amps. You can find them for $25 (at least in Japan) that have BT 5.0 and only 3.5mm inputs but can accept up to 24vdc and produce incredible sound for next to no money, however you have to supply your own 24vdc, 5-6amp power supply effectively doubling the price. The 3116's are great in their own regard (like I said I have a few), but this is a thread on the DA-9.
Like you, I have also been down the rabbit hole of class-D amplification for about 8 years now and with my equipment, the DA-9 is not only a standout, it's possibly my favourite amplifier that I own that isn't tube driven and fully customized by myself.
SMSL must get their act together as far as quality control. It doesn't matter what the financial spend is, it should be built right the first time. I will not make excuses for them. But I will offer a potential fix for users who've encountered the same noise issue that I did, and there are several users on this forum who have had the same issue, some have pre-empted the noise issue after reading my early contributions towards the first 10 pages or so.
My amplifier in it's current state hasn't been turned off/unplugged in over a month as I'm always listening to something. I've encountered absolutely zero issues of any kind much like my previous DA-8s which was also used in a manner where it was never turned off other than occasionally moving it from room to room, only to be immediately repowered. I stand by SMSL in the hopes that they will improve their quality control once they stop messing around and producing multiple units to see which one will "hit/sell". I'm sure that they are building all of these new units to see which ones will sell, and which won't. They use essentially the same chassis in 3-4 sizes and the guts can be swapped out to suit another device at a moments notice. I have no doubt that they will get their act together shortly. Once these new releases are over, hopefully they'll start on firmware updates and not entirely new circuit boards as they did with the first SU-8's (The silver units with tiny OLED screens).
Hopefully we'll get clear answers about the performance of the DA-9 that can be measured one day. And hopefully by that time the QC issues are rectified before Amir goes and measures the amplifier. I would volunteer my amplifier for measurements but mine is no longer "factory" so the measurements wouldn't be the same as a completely factory fresh unit. Plus I'm not paying for shipping to another country for testing.