Pico audio pack with rpi pico w on circutit python - no audio

Hey folks,
i downloaded the adafruit-circuitpython-raspberry_pi_pico_w-de_DE-8.0.0-beta.4.uf2 to the pico w, then i flashed the example sketch with the pins adopted to the pico audio and after that i only hear noise on high gain and nothing on low gain.
Can someone help me?
Best nanu

import time
import array
import math
import audiocore
import board
import audiobusio

audio = audiobusio.I2SOut(board.GP10, board.GP11, board.GP9)

tone_volume = 0.1  # Increase this to increase the volume of the tone.
frequency = 440  # Set this to the Hz of the tone you want to generate.
length = 8000 // frequency
sine_wave = array.array("h", [0] * length)
for i in range(length):
    sine_wave[i] = int((math.sin(math.pi * 2 * i / length)) * tone_volume * (2 ** 15 - 1))
sine_wave_sample = audiocore.RawSample(sine_wave)

while True:
    audio.play(sine_wave_sample, loop=True)

Try to add a DigitalOutput for GP22 and pull it high. This is the active-low mute-pin.