Stereo Tool

We have been having this weird and really annoying issue for some time now:

Stereo Tool plays fine, and I can mess around with the settings with no issues. But once in a while, ST all of a sudden completely stutters all the audio (so much, that it is totally unlistenable). If i then go to Configuration -> Sound cards and click "Restart", to restart the sound card, the issue is completely gone and audio is back to normal again.
I find this really strange, as I am not pushing ST hard at all. There is plenty of CPU headroom (the red bar in "CPU & Latency" is at about 35%).

Please listen to this example (recorded from FM): https://www.dropbox.com/s/0r1k5suhxngb9 ... 9.m4a?dl=0

Usually, the issue happens when I'm navigating around in Stereo Tool - but I am not changing any settings that will affect the CPU usage. Last time it happened just when i was saving a preset. However, the first time I noticed the issue, I was not touching Stereo Tool at all. I was just listening to the station, when it happened. The preset running at that time was an almost unmodified version of "Ibiza FM", and I have found that this preset is more sensitive to the issue than other presets.

If i push ST really hard, I can force the issue to happen - but not always. Please listen to this example: https://www.dropbox.com/s/cjoeytum9hoxb ... 9.m4a?dl=0. In this example I forced the issue to happen by pushing all the CPU intensive settings to max.


Another thing I find strange, is that even though the settings "Detect and attempt to fix sound card/VLC timeouts" and "Restart on crashes or unsolvable sound card timeouts" is turned on, the sound card has never been restarted automatically to fix the issue, as far as I'm aware of.

Info about our system:
Windows 7
64-bit Stereo Tool v7.50
Marian Trace Alpha
Intel Core i3-4330

Sounds like your sounds card buffer ran out of steam, try increasing it. Buffer issues and cpu overload, but your cpu is adequate..Do you have any anti virus or windows update running in the back ground? and then there is the old win 7 64 bit issue that some have had.I run 32 xp pro sp2 no issues...maybe hans or bojcha will chime in.

A few questions:
1. Are you using ASIO or non-ASIO?
2. What's the buffer size?
3. Do you use multiple outputs?
4. After the hiccups I hear silence and then it starts playing normally again - in the 1st sample it's ok for about a second before the silence also. Are you pressing the restart button there, or does this happen automatically?
5. What's your input? Something like Virtual Audio Cable? Are you using different sound cards for input(s) and output(s)?

I have just one question. Do you use stream to receive source, and how?
1st "skipping" sounds like when encoder goes crazy. And 2nd is really buffer.

Thanks for your suggestions. I am running antivirus actually, but the most lightweight one I could find - Avast. Maybe I should remove it... Windows Update (and other unnecessary services) is disabled. Edcast is running in the background for streaming. TightVNC for remote controlling.
1. I am using ASIO for input and FM Output.
2. Input Buffer Size: 0.000 sec - FM Output Buffer Size: 0.016 sec - Normal Output Buffer Size: 1.204 sec
3. I am using FM Output and Normal Output (for streaming - audio is being send to Edcast with VB-Audio Cable). Normal Output is at the moment a de-emphasized version of FM Output.
4. Yes, the very moment I press the restart button, the audio goes normal right before the silence. I have also noticed that in earlier occasions.
5. The input is the analog input of the Trace Alpha, and the FM Output is of course the Trace Alpha as well.
No stream to receive source - it's received from the Trace Alpha.


I appreciate your help guys!

Ah, so normal output is going to a different sound card (vb cable). I'm guessing that the normal output buffer is 100% full when this happens - it must be filling up from the start. Once it's full it will block the audio passing through the software, and you'll get this effect. If you increase the normal buffer sizw it will take longer before this happens.

Can you verify this? If you're on fm now and need an immediate solution, turn normal ouyput off, or send it to the sound card as well (for example to a digital output if you don't use it) and try to stream from there.

Another question. Do you have priority at "high" or "realtime" ?

I'm not sure I totally understand. But to test, I decreased the Normal output buffer all the way down to 0.052 sec, and the audio played with no issues. The "buffer bar" was filled up all the way (lightblue color). I then tried to increase Quality from 80% to 100%, just to see what would happen - and almost immediately, the audio (on FM) began to stutter again. I then pressed the Restart sound cards button, and the audio now plays fine (and the Quality slider is still at 100%).
The blue buffer bar under Normal Output is now at about 80%, and not decreasing for now.
EDIT: it is decreasing. I will monitor the FM signal and see what happens...

Priority is at Realtime.

I believe Hans was suggestion you could try the exact opposite. Actually raising the normal output buffer setting would make it take longer to fill that buffer, which might be desirable in your case.

I got that part, but thanks I'm just trying to see if I can force the issue to happen.
What I don't get, however, is the buffer bar. I am thinking that the more filled up the buffer bar is, the better... But...
If that is the case, then a filled buffer must be bad...? Maybe I am confused by the term "full buffer". Isn't a full buffer the hole purpose of a buffer? I would believe that a empty buffer, however, is bad (I think it's pretty self-planatory) but please, do correct me if I am wrong.