这是一台集成了解码、前级、后级、蓝牙、低音炮输出<—-?????的设备……壳子是SMSL VMV新系列的家族设计,但是比A1和D1se整个大了一圈,整体外观我没啥可以多说的了,就吐个槽—-这货有风扇=。=(虽然似乎是温控的)。好了,开始测量:The SMSL VMV A1 and SA400 have just been released the other day, but it seems that the next SMSL VMV A2 is scheduled to be released.
The content seems to be a model that extends the digital input of the SA400's AX5689 chip.
It is the measurement data by the wolf.
https://www.l7audiolab.com/f/smsl-vmv-a2-amp/
Looking at the graph of 8R-THD+N-Ratio-vs-Measured-Level, when it exceeds 20W, the distortion of Rch-Lch begins to differ, and when it exceeds 80W, the difference becomes large. When the output increases further, the distortion increases at once and the characteristics of Rch-Lch overlap. The difference in the part around 100W is the difference in the level region where the distortion is sufficiently low, so it will not actually be a problem.Seems like a pretty interesting product, no mention of price here. Almost 8db difference between ch1 and ch2 at 100w, wonder why? Not that we'd be using that much power anyway?
What concerns me is that it makes a whine (tonal noise) audible to Amir at 1 ft distance. Audibility will of course depend on the background noise level of the room and the listener's acuity. As a rule, I think manufacturers should make audio components that do not whine, buzz, hiss, or hum audibly. (It's not just budget manufacturers -- I returned an expensive power amp whose "silent" fan was plainly audible to me from the listening seat.)
Have an issue similar to this with my DA9. Powered on with nothing connected the unit makes a high frequency squealing noise that changes with screen brightness, but never goes away.
I have this exact same experience with the SMSL SU-8 DAC, but only occasionally.
The unit sometimes emits a high pitched whine (sound directly from DAC), and yes it changes if I adjust the menu with the remote (e.g. changing the volume causes the whine to change in pitch, then after time-out when the display goes back to what it was showing, it goes back to the previous pitch).
Sometimes I turn on the DAC and there is only silence.
It is odd and I remember reading somewhere it could be caused by the display itself.
Today the DAC was making the noise again so I adjusted the screen “brightness” (all levels) and waited for it to time-out and “return” to previous display.
I have been using Level 3 which sometimes makes noise.
When adjusting settings (changing volume/menu) the sound reduces/changes pitch, but still audible. Then after time-out when it returns to previous display (input/sample rate etc) the sound gets louder and higher pitch again.
Brightness level is 1-4 levels + “Auto display off” (level 0).
I tried this process with Level 4 brightness, the sound is less both when adjusting and after time-out but still there.
I tried Level 1, very very quiet noise, I can barely hear it. I will keep this setting since I would like to know when DAC is on.
“Auto display off” (Level 0) is also no noise.
Yeah, no screen off feature on the DA9 unfortunately. I'm awaiting a response from Apos to see about exchanging or just flat out returning the unit. It would be perfectly usable in a living room setup, but for the near field application I want to use it in, the squeal will not fly.
I am using in near-field also.
“Auto display off” & Level 1 brightness on SU-8 is silent at listening position.
DA-9 screen is much bigger and also color compared to SU-8, so maybe Level 1 brightness on DA-9 is still an issue with noise.
Maybe Official ASR DA-9 review should include unit noise measurement/subjective noise description.
SA400 is now $100 less on Amazon too. I just got mine for 700. returning once da9 arrives.