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Thread: Teensy 4.1 with Audio board random noise and pitches

  1. #1

    Teensy 4.1 with Audio board random noise and pitches

    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.

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    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

  2. #2
    Update:
    This is the output of the audio board on the oscilloscope
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  3. #3
    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

  4. #4
    Senior Member
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    Quote Originally Posted by alessandromrc View Post
    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

  5. #5
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    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.

  6. #6
    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!

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