HiFiBerry Amp2 on RPi 3A+, playback is "suddenly" too slow

I've been using this combo (Amp2 mounted to a RPi 3A+), running with piCorePlayer, for about 15 months, with no problems whatever. The power supply (fed to the AMP2) is 20V/6A.

A couple of days ago I had to adjust some wiring, and so I had removed the boards from the box they live in, and handled them a bit. (The Pi lives in a ventilated box on the floor behind the speakers.)

The next time I used it, and ever since, playback has been at half speed. I tried reconfiguring pCP to use the headphone jack, and audio works fine in that case. When I configure back to "HiFiBerry DAC+ (and Pro, AMP2)", I'm back to half speed again. I've examined both boards (using a loupe) for damaged/missing components. I've swapped in a different RPi, with no change in behavior.

It's been a long time since I've been overly worried about static damage, and in this case (when I first moved/handled the boards) the power remained on and the boards were never separated.

Any ideas? Is my amp toast? :-/

Paul Fox December 17, 2022 20:23

I think I've solved it.

I was doing some searches for more information, here on the HiFiBerry community forum, and found someone mention that pigpiod was causing their hifiberry board to not work at all.

As it happens, I do use pgpiod. I don't use it on the machine with the hifiberry hat, but because I maintain all of my pCP machines uniformly, my startup script starts pgpiod on all of them, even if it won't be used. I assumed the daemon did nothing at all until something connected to it.

But it turns out that if I don't run pgpiod on startup, then the hifiberry board works just fine, and audio is good, and I'm a happy guy.

Now, I've been running pgpiod on that board forever. I don't know why the behavior changed. But if it caused a pin to float which should have had a firm 0 or 1, then its behavior might change over time? Or, perhaps pgpiod was updated recently. I haven't checked that.

Anyway, lesson learned. It does seem like pgpiod should have a way of configuring pins that it shouldn't ever touch.

HiFiBerry Amp2 on RPi 3A+, playback is "suddenly" too slow

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