Hi Bob,
Thanks for the update. How is your power distribution consistency? [funny story] My friend used to live in a block of flats and he was getting dropouts due to unlocks of DAC digital input every time someone called elevator in the building. So he only listened to music late in the night when chances of someone needing an elevator was low. [/funny story] Power distribution and cabling can sometimes amplify the effect of mains glitches or instabilities. Anyway, please keep us posted.
Thank you.
Pavel
Occasional glitches in the audio (very short, momentary dropouts)
Re: Occasional glitches in the audio (very short, momentary dropouts)
Power distribution in this room is incredible. I have a dedicated 100 amp (that's 100 amp) 240 volt service coming into Studio A. That goes into 5 Surge-X EMI/RFI filters and 5 20 amp 120 volt circuit breakers. All lines are star run back to this central box through steel conduit. I could go on, but let me finsh by saying that After I finished this renovation, the noise in the power line was reduced by over 20 dB in all modes: Line to neutral, line to ground, and neutral to ground. Even the acoustic noise from power transformers was reduced.
Prior to the installation of this dedicated line, I would play my Shuttle Launch recording that I made and the lights would dim! After the instalation, all power amp headroom has increased over 3 dB! So I can play peaks 3 dB louder in the room --- just by virtue of the new power installation.
So, yeah, my power is taken care of
Prior to the installation of this dedicated line, I would play my Shuttle Launch recording that I made and the lights would dim! After the instalation, all power amp headroom has increased over 3 dB! So I can play peaks 3 dB louder in the room --- just by virtue of the new power installation.
So, yeah, my power is taken care of
Re: Occasional glitches in the audio (very short, momentary dropouts)
Progress, I guess: I played a Blu Ray of a concert video with 48 kHz sampling, connected AES output 1/2 into a Prism Callia DAC. As you may know, the Prism uses a unique and very stable architecture with two stages of pure analog PLL. The Prism does not use an ASRC. This is almost unique in the audio industry.
Anyway, there were 2 dropouts in 15 minutes time
. I didn't get to look at the Vanity status screen at the time, but I don't think this has to do with the FIFO buffer switch. I powered down the Blu Ray, then the buffer went to 0%. Powered it back up and played again, buffer somewhere near 30% if I recall. I didn't have tht patience to wait longer, but for the next 15 minutes or so, the sound was clean and there were no dropouts. I don't know if you can do any better, but it would be nice if you could investigate this further. Thanks.
Are you feeding the AES/EBU outputs with 110 ohms impedance?
Best wishes,
Bob
Anyway, there were 2 dropouts in 15 minutes time
. I didn't get to look at the Vanity status screen at the time, but I don't think this has to do with the FIFO buffer switch. I powered down the Blu Ray, then the buffer went to 0%. Powered it back up and played again, buffer somewhere near 30% if I recall. I didn't have tht patience to wait longer, but for the next 15 minutes or so, the sound was clean and there were no dropouts. I don't know if you can do any better, but it would be nice if you could investigate this further. Thanks.Are you feeding the AES/EBU outputs with 110 ohms impedance?
Best wishes,
Bob
Re: Occasional glitches in the audio (very short, momentary dropouts)
Dear Pavel: Some progress, but indications are not good.
I played a Blu Ray with a concert video with a 48 kHz 5.1 soundtrack. I took AES output channels 1/2 and fed that to a Prism Callia DAC. As you may know, the Prism DACs are almost unique in the industry, employing a pure, two-stage all-analog Phase Locked Loop. So Prism couldn't be any further apart from the ESS architecture than you can imagine. There were two dropouts in 15 minutes. I then powered the Blu Ray down, Buffer went to 0%. and back up, buffer went to I think 30%. I played for 15 minutes and there were no dropouts and I didn't have any patience, the buffer was pretty stable and hardly changing. I really don't think it was the buffer changing that caused the prism to drop out. I think it was something else. It would be nice if you could further investigate these occasional dropouts.
Are you using 110 ohm output impedance from the AES/EBU?
Best wishes,
Bob
I played a Blu Ray with a concert video with a 48 kHz 5.1 soundtrack. I took AES output channels 1/2 and fed that to a Prism Callia DAC. As you may know, the Prism DACs are almost unique in the industry, employing a pure, two-stage all-analog Phase Locked Loop. So Prism couldn't be any further apart from the ESS architecture than you can imagine. There were two dropouts in 15 minutes. I then powered the Blu Ray down, Buffer went to 0%. and back up, buffer went to I think 30%. I played for 15 minutes and there were no dropouts and I didn't have any patience, the buffer was pretty stable and hardly changing. I really don't think it was the buffer changing that caused the prism to drop out. I think it was something else. It would be nice if you could further investigate these occasional dropouts.
Are you using 110 ohm output impedance from the AES/EBU?
Best wishes,
Bob
Re: Occasional glitches in the audio (very short, momentary dropouts)
Hi Bob,
Thanks for the additional info. The XLRs are correct output impedance and so are the coax outputs on other modules. If you are getting those dropouts on two different DACs and you think it is not buffer adjustment related, it sounds like there is something else going on. There are a few things we can try, but first would you be happy to record and send us back some diagnostic data from the unit?
Best Regards,
Pavel
Thanks for the additional info. The XLRs are correct output impedance and so are the coax outputs on other modules. If you are getting those dropouts on two different DACs and you think it is not buffer adjustment related, it sounds like there is something else going on. There are a few things we can try, but first would you be happy to record and send us back some diagnostic data from the unit?
Best Regards,
Pavel
Re: Occasional glitches in the audio (very short, momentary dropouts)
Thanks, Pavel. Of course I'm happy to send diagnostic data. Anything you'd like. Well, the dropouts on the ESS DAC do seem to be buffer-related, or at least aggravated by sample frequency micro-adjustments associated with keeping the buffer from over or under flowing. But the other DAC, the Prism, not being ESS and having a pure 2-stage analog PLL, is usually not sensitive to slight errors in source sample rate accuracy. The Prism DAC seems to be very stable and dropout with other sources. And keep in mind that sample rate is 48 kHz for these, which is not a big challenge for any SPDIF or AES/EBU DAC
The hard part, of course is for you to debug at a distance. I have the tools to look at eye pattern, probably, if you show me how to connect them, if that will help you.
The hard part, of course is for you to debug at a distance. I have the tools to look at eye pattern, probably, if you show me how to connect them, if that will help you.
Re: Occasional glitches in the audio (very short, momentary dropouts)
Hi Bob,
Thanks for offering your assistance to remotely debug the dropouts you are experiencing. I would suggest to start with logging a diagnostic serial dream from the unit via USB. For this you would need a diagnostic firmware (which has the serial stream enabled) and a serial terminal which can dump the stream into a file.
The firmware can be found here: [url=https://audiopraise.com/downloads/temp/VanityPro_FW_V5_2_1_buf3_7_uart_enc.dfu]FW_BUF3_UART[/url].
And brief instructions how to connect to the unit and log the diagnostic stream:
[url=https://audiopraise.com/downloads/temp/Logging%20Diagnostic%20Output%20from%20VanityPRO.pdf]UART Instructions[/url].
The idea is that you are recording the internal diagnostic data while you are playing a film or music and if a dropout occurs you just note down the approximate time it happened since the start of logging. Then we can match that time instant to the diagnostic data around that moment and see if there are any irregularities. You can log a whole listening session, because a couple hours of diagnostic data is just a few hundred kbytes. Any questions, please ask.
Best Regards,
Pavel
Thanks for offering your assistance to remotely debug the dropouts you are experiencing. I would suggest to start with logging a diagnostic serial dream from the unit via USB. For this you would need a diagnostic firmware (which has the serial stream enabled) and a serial terminal which can dump the stream into a file.
The firmware can be found here: [url=https://audiopraise.com/downloads/temp/VanityPro_FW_V5_2_1_buf3_7_uart_enc.dfu]FW_BUF3_UART[/url].
And brief instructions how to connect to the unit and log the diagnostic stream:
[url=https://audiopraise.com/downloads/temp/Logging%20Diagnostic%20Output%20from%20VanityPRO.pdf]UART Instructions[/url].
The idea is that you are recording the internal diagnostic data while you are playing a film or music and if a dropout occurs you just note down the approximate time it happened since the start of logging. Then we can match that time instant to the diagnostic data around that moment and see if there are any irregularities. You can log a whole listening session, because a couple hours of diagnostic data is just a few hundred kbytes. Any questions, please ask.
Best Regards,
Pavel
Re: Occasional glitches in the audio (very short, momentary dropouts)
Thanks, Pavel. I'm traveling right now so when I get back. Would this diagnostic firmware change any of the desirable functions that are in the current release firmware?
Re: Occasional glitches in the audio (very short, momentary dropouts)
Hi Bob,
No changes to functions and features. Actually there are some minor improvements to the frequency tracking and buffer management which will be later included in a new official fw release. Safe travelling!
Best Regards,
Pavel
No changes to functions and features. Actually there are some minor improvements to the frequency tracking and buffer management which will be later included in a new official fw release. Safe travelling!
Best Regards,
Pavel
Re: Occasional glitches in the audio (very short, momentary dropouts)
Hi Pavel
Just want to add my 2 cents since I'm in a similar situation. I have two chains with a headphone system. When I'm using Mac Pro->VanityPRO->Weiss DAC204, the dropouts barely happened, maybe every 30mins or even longer, it's definitely listenable, but that was only improved by the latest firmware upgrade. My second chain is the recently added Eversolo A6 ME->Vanitypro->Weiss DAC204, it drops about every 5 mins, and did happen when the buffer hits 20%/80% threshold. And I'm using the same Fibbr 8K HDMI cable.
So maybe the dropout has sth. to do with the source as well? I can't find any way to adjust the DAC204 PLL BTW.
Cheers.
Just want to add my 2 cents since I'm in a similar situation. I have two chains with a headphone system. When I'm using Mac Pro->VanityPRO->Weiss DAC204, the dropouts barely happened, maybe every 30mins or even longer, it's definitely listenable, but that was only improved by the latest firmware upgrade. My second chain is the recently added Eversolo A6 ME->Vanitypro->Weiss DAC204, it drops about every 5 mins, and did happen when the buffer hits 20%/80% threshold. And I'm using the same Fibbr 8K HDMI cable.
So maybe the dropout has sth. to do with the source as well? I can't find any way to adjust the DAC204 PLL BTW.
Cheers.