Teensy 4.1 with Audio board random noise and pitches

[alessandromrc]

Hi, this is the first time using the audio board on my Teensy 4.1, I've connected the two boards toghether using jumpers on breadboards.



The problem that I actually have is that the board is just outputting a lot of noise and random high pitch sounds, the two boards are being powered through a powerbank, and I'm using the guitar example sketch to test everything out.

Any help is greatly appreciated

[alessandromrc]

Update:
This is the output of the audio board on the oscilloscope

[alessandromrc]

I've noticed that the IC on the audio board becomes really Hot, I assume this is related to the fact that the board/IC is just non functioning correctly

[kd5rxt-mark]

I've noticed that the IC on the audio board becomes really Hot, I assume this is related to the fact that the board/IC is just non functioning correctly

You should double-check your wiring . . . it sounds like there's an incorrect connection somewhere. Also, where/how are you trying to measure the audio output with your o-scope ?? If you connect only the center pin of your o-scope probe to one of the two headphone output pins, then the signal will not be properly referenced, so you'll likely see *lots* of noise on the o-scope. If you connect both the center pin & the collar of your o-scope probe to the two headphone output pins, you'll be grounding the audio pin connected to the collar, & the headphone output definitely does not like that at all. Your measurements should be taken with the o-scope probe connected to the Line Out audio pins (GND & L, or GND & R).

Mark J Culross
KD5RXT

[MarkT]

The fast I2S signals (especially MCLK) might not be reliable with long jumpers like this, especially with all that loop area - bundle them all together if you can to improve signal quality. A large loop is an antenna, both radiating and receiving noise.

The normal way of stacking the audio adaptor is advised to prevent such issues being a problem.

Overheating chips can be due to power being miswired. I'd suggest its always a good idea to double check power and ground continuity before powering up any circuit.

[alessandromrc]

Thank you kd5rxt-mark and MarkT, I've seen that the SGTL5000 pins were shorted probably because of bad soldering at the factory or gods knows where. I've just got a UDA1334a DAC and it works really good!