When the bit or sampling rate changes, the first 1-2 seconds of the song are cut off.

byul0615

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Apr 8, 2025
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I am listening to Apple Music high-resolution lossless sound source by optically connecting the source device (iPhone 15) to WiiM AMP via DDC (SMSL PO100).
As you all know, even if you set it to high-resolution lossless, depending on the sound quality of the released sound source, 24bit 192khz (almost none), 96khz, 48khz, 44.1khz, and even 16bit sound source are played.
As a result, when the current song ends and the next song is played and the bit or sampling rate changes, the first 1-2 seconds of the song do not play and skip.
I sent a ticket with the above symptom, and they checked my log and confirmed that the above symptom occurs when the sampling rate changes in the DDC, and told me to find a way to fix the sampling rate in the DDC.(In their words, this is because the WiiM AMP re-locks the sampling rate.)
However, I connected my iPhone to WiiM AMP using DDC in order to listen to high-quality sound sources with bitperfect (iPhone, iPad only, not Mac), and even if it were possible to fix the sampling rate (which is impossible because DDC does not have such a setting anyway), I don't think it would solve the fundamental problem because upsampling or downsampling would occur, and I don't plan on doing so.
And isn't it the source device that changes the bit and sampling rate, not the DDC?
This is my first passive speaker system, so I have little knowledge about amps, sources, sampling rates, etc.
I'm wondering if this is a problem that can be solved by changing the DDC, or if it's an unavoidable symptom since the WiiM AMP goes through a process called re-lock when the bitrate or sampling rate is changed in any way.
It's been about 2 weeks since they last contacted me about purchasing and testing a DDC (SMSL PO100), if anyone has had experience with or resolved this situation please advise.
 
I noticed a drop out, or very low digital noise "tssh" on track changes of different bit rates. Guess it depends on the DAC...could try using analogue out to test...
 
I noticed a drop out, or very low digital noise "tssh" on track changes of different bit rates. Guess it depends on the DAC...could try using analogue out to test...
Anyway, the analog connection is set to a fixed sampling rate in the WiiM Home app, so I think I'll have to find another solution since I'm planning to connect with bit perfect.
 
Anyway, the analog connection is set to a fixed sampling rate in the WiiM Home app, so I think I'll have to find another solution since I'm planning to connect with bit perfect.
If you are dead set on bit perfect you miss out on room correction which is very likely much more beneficial.
 
Anyway, the analog connection is set to a fixed sampling rate in the WiiM Home app, so I think I'll have to find another solution since I'm planning to connect with bit perfect.
I’m puzzled - doesn’t the SMSL output digital, not analogue? Where does that figure?
 
If you are dead set on bit perfect you miss out on room correction which is very likely much more beneficial.
Rather than being obsessed with bit perfect, I just want to listen to the best sound quality possible.
Since I wouldn’t buy it if I wasn’t going to use it, I try to utilize the available features to the fullest.
Of course, I also actively utilize room correction.
 
Rather than being obsessed with bit perfect, I just want to listen to the best sound quality possible.
Since I wouldn’t buy it if I wasn’t going to use it, I try to utilize the available features to the fullest.
Of course, I also actively utilize room correction.
How do you use room correction and also maintain a bit perfect connection?
 
How do you use room correction and also maintain a bit perfect connection?
Now I understand what you are saying, I guess my lack of understanding of bitperfect made my answer sound strange.
I would appreciate it if you thought of it as something that aims to maintain the sound quality of the source device to the maximum from a beginner's perspective.
 
No, I never noticed any dropouts when listening to Apple Music using that connection method.

Perhaps it’s due to the SMSL PO100 that the OP is using. 🤔
I have a question, in the answer I got from the WiiM support team, when the DDC changes the sampling rate (I asked them if it's the source device that changes the sampling rate and the DDC just relays it), the amp re-locks to the new sampling rate, so the first 1-2 seconds of the song are lost.
If that doesn't happen with the specific DDC you mentioned, then it seems to me that the amp doesn't re-lock the sampling rate when playing through that DDC.
Are you sure you listened to music with the same connection as me?
Source device (iPhone) - USB C - DDC - Optical connection - WiiM AMP - Speaker,
audio playback is Apple Music high-resolution lossless (streaming or download playback) on iPhone (or iPad).
 
I don't have that issue with my Cubilux converter either too.
I ask the same question I asked the person above., in the answer I got from the WiiM support team, when the DDC changes the sampling rate (I asked them if it's the source device that changes the sampling rate and the DDC just relays it), the amp re-locks to the new sampling rate, so the first 1-2 seconds of the song are lost.
If that doesn't happen with the specific DDC you mentioned, then it seems to me that the amp doesn't re-lock the sampling rate when playing through that DDC.
Are you sure you listened to music with the same connection as me?
Source device (iPhone) - USB C - DDC - Optical connection - WiiM AMP - Speaker,
audio playback is Apple Music high-resolution lossless (streaming or download playback) on iPhone (or iPad).
 
I ask the same question I asked the person above., in the answer I got from the WiiM support team, when the DDC changes the sampling rate (I asked them if it's the source device that changes the sampling rate and the DDC just relays it), the amp re-locks to the new sampling rate, so the first 1-2 seconds of the song are lost.
If that doesn't happen with the specific DDC you mentioned, then it seems to me that the amp doesn't re-lock the sampling rate when playing through that DDC.
Are you sure you listened to music with the same connection as me?
Source device (iPhone) - USB C - DDC - Optical connection - WiiM AMP - Speaker,
audio playback is Apple Music high-resolution lossless (streaming or download playback) on iPhone (or iPad).

Confirmed by Apple Music's Hi-Res Lossless track.

Android tablet (or phone) > USB to Optical > Ultra
 
Confirmed by Apple Music's Hi-Res Lossless track.

Android tablet (or phone) > USB to Optical > Ultra
Ah, if it's Android... bit perfect isn't possible yet, right?
I understand that it's output after resampling (probably 48khz in case of wired connection?).
If so, it seems like a slightly different case from mine.
 
Ah, if it's Android... bit perfect isn't possible yet, right?
I understand that it's output after resampling (probably 48khz in case of wired connection?).
If so, it seems like a slightly different case from mine.
The Ultra screen and WHA show up to 198 kHz, not 48 kHz fixed.
 
Are you sure you listened to music with the same connection as me?
Source device (iPhone) - USB C - DDC - Optical connection - WiiM AMP - Speaker,
audio playback is Apple Music high-resolution lossless (streaming or download playback) on iPhone (or iPad).
In my case, I was using an iPhone with Lightning port, so I used the Apple Camera adapter and a USB A to USB C adapter, then the Cubilux USB C to Optical adapter, and finally optical connection to WiiM Amp.

I also used an iPad with USB C port, and connected the Cubilux USB C to Optical adapter, and then optical to the Amp.

In both cases I was using Apple Music, and never had any issues with sample rates changing between tracks.
 
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