ProtoDAC TDA1387 X8 project

[springle19]

Tim - I did try your  queuing suggestion for which thanks . . . but I'm still get a varying selection of clicks occurring  (some pronounced, others quieter) across the queue listing, but not in any noticeable pattern

Mark - new module purchased and installed - still getting the  fairly frequently occurring click on track start  either (i) as per Tim's queuing suggestion above, or  (ii) playing tracks straight from an album.  Continuation of the issue with new module tends to suggests the module is not the cause.  Anything else on the DAC board - component-wise -  I should be looking at or testing?

Let me know

Best, Simon P

No problem with the DAC board other than the module. Maybe something in the component chain. For example, a very sensitive preamp? Try software volume or CamillaDSP volume control and go directly to the power amp.

Mark - re Camilla DSP, under File Management I have V2-ProtoDac selected from the dropdown menu - correct ??- but at the top of the Configuration page under Signal Processing, the drop down menu is not showing/open for me.  Am I missing something obvious?

Separately, is a dry solder joint on the module a possible explanantion?

Simon P

With Camilla the config is selected in the "Signal processing" dropdown on the CamillaDSP Config screen. Then SAVE.

You can also set this to "Off" and instead turn on ALSA Polarity Inversion. This setting is in the MPD section on the Audio Config screen.

For troubleshooting though I would leave both CamillaDSP and ALSA Polarity Inversion set to Off.

Also,
1. Do you get any glitches during Radio Station playback?
2. What model Raspberry Pi?

Tim

Your questions: 
> 2 - Raspberry Pi 4, 8GB
> 1 - Yes, there are audible clicks at the start of playing radio stations in the queue.  Encouragingly, I can't hear other artifacts in playing radio stations once they are launched, so this feels like a 'launch playing' issue. In this sense, my click 'problem' in playing radio queue items mirrors that in playing queued album tracks - clicks at the start of play, nothing noticeably concerning thereafter

Your advice: 
ASLA & Camilla DSP polarity inversions now turned off. My observation under these conditions is that clicks at the start of playing queued items are less frequent (now maybe 1 in 10 occasions) compared with the 'polarity inversion on' scenario (maybe 1 in 5 items) . . .  and those 'polarity inversion off' clicks that do occur do seem to be a bit quieter. so things are better.  Note that the occurrence of clicks is not constituent - sometimes a queued track/radio station will click at the start of play, other times it won't.  Hard to spot the pattern of repetition here.

A bit subjective this, I know, but does it help?

Simon P

[DRONE7]

Just curious..what power supply are you using for the Pi (and the Protodac if separate)
Are they all plugged into the same mains outlet ?
Possibility of grounding loops can manifest as odd noises especially as content is started and stopped.

As many others of us use the same hardware/DAC/OS etc without clicks then there must be some configuration with your chain external to MoOde. Perhaps check all cables and or substitute others to test.

[Tim Curtis]

This type of non-regular glitch could be due to how the DAC chip reacts to the audio signal suddenly starting or stopping i.e. when MPD opens/closes the ALSA output.

I rarely get a glitch on my ProtoDAC but its on top of an Allo Kali Reclocker and the Kali and Pi are fed from separate power supplies: Official Pi 5 supply and an Intertek switch mode PSU that Allo used to sell. Nothing fancy.

[DRONE7]

One of my Protodacs is fed by a Kali, one is fed from the output of a DIYinHK USB to i2c and another from an AK4137 resampler and none produce glitches.
I will try Pi direct and report.

[hifinet]

This type of non-regular glitch could be due to how the DAC chip reacts to the audio signal suddenly starting or stopping i.e. when MPD opens/closes the ALSA output.

Yes. If I ever get a tic (rarely), it is always after the last track, presumably when MPD closes the ALSA output.

Using a powerbank for the RPi and LiFePO4 battery supply for the Allo Kali/ProtoDAC. SBC Jumper on the Kali is off, so the supply is separate from the RPi.

[DRONE7]

One of my Protodacs is fed by a Kali, one is fed from the output of a DIYinHK USB to i2c and another from an AK4137 resampler and none produce glitches.
I will try Pi direct and report.

An hour or two now Pi4 and ProtoDac via i2c MoOde 9.05 and no clicks or glitches. Tried with both Software and Fixed volume settings.

(Powering Pi and ProtoDac from Salas L-adapter so plenty of grunt there. 
When I first plugged the ProtoDac into the Pi4 using another Official Pi power supply it would not boot...greedy little ProtoDac   :-)

[hifinet]

Some SMPS don't like to power a cap (like the 2000uF cap in ProtoDAC), since it looks like a short and they go into protect mode.

[springle19]

One of my Protodacs is fed by a Kali, one is fed from the output of a DIYinHK USB to i2c and another from an AK4137 resampler and none produce glitches.
I will try Pi direct and report.

An hour or two now Pi4 and ProtoDac via i2c MoOde 9.05 and no clicks or glitches. Tried with both Software and Fixed volume settings.

(Powering Pi and ProtoDac from Salas L-adapter so plenty of grunt there. 
When I first plugged the ProtoDac into the Pi4 using another Official Pi power supply it would not boot...greedy little ProtoDac   :-)

[springle19]

One of my Protodacs is fed by a Kali, one is fed from the output of a DIYinHK USB to i2c and another from an AK4137 resampler and none produce glitches.
I will try Pi direct and report.

An hour or two now Pi4 and ProtoDac via i2c MoOde 9.05 and no clicks or glitches. Tried with both Software and Fixed volume settings.

(Powering Pi and ProtoDac from Salas L-adapter so plenty of grunt there. 
When I first plugged the ProtoDac into the Pi4 using another Official Pi power supply it would not boot...greedy little ProtoDac   :-)

Bob - to be clear, you're saying you have the ProtoDac powered by the Pi 4 via the GPIO connector, but using a single Salas L-adapter? 

I have the same physical configuration - ie I've slotted the ProtoDac directly on top of my Pi 4. However, in my case, the whole combo is powered by the standard USB power supply which comes with the Pi 4, via its USB socket.  Your view is that this may not be juicy enough though for the combo, yes?

Re other variables, am using the same cables and input sockets on my amp as I had for my first cheap/cheerful Chinese DAC which was limited tonally, but glitch/click free . . . . so I don't think my clicking issue is either of these downstream factors

I'm open to any more ideas!

Best, Simon P

[DRONE7]

Simon,

Bob - to be clear, you're saying you have the ProtoDac powered by the Pi 4 via the GPIO connector, but using a single Salas L-adapter?

Yes.

As MoOde is so wonderfully efficient the CPU load is generally low even when indexing and with CPU set to Performance rather than On Demand.
Mostly of my output is via USB to other USB-i2c-Hats or devices.
Hence I am a little parsimonious with power supplies and run my Pi1/2/and Zeros from the little 2-Amp apple chargers I buy used in bulk at $3 each.
My Pi3s I run on Official Pi2 supplies and my Pi4 usually runs on an official Pi3 supply.

When running HATs I either supply them separately or use the Salas L-Adapter to run both the Pi and it's HAT.
As I was quickly experimenting with the Pi4 and ProtoDac attached I forgot to change out the power supply and the combo wouldn't boot on the Pi3 supply..of course.
I swapped it out for the super-grunty L-adapter.
As I don't have an official Pi4 supply I can't test it with the combo sorry.