It would be great if Digilent has created a Pmod module based on an audio codec with an integrated amplifier, such as for example CS42L52, that can directly drive a speaker.
Unfortunately, the only Pmod that could be qualified as a codec Pmod that I could find is Pmod I2S2. Its output part is based on CS4344 DAC without any amplifier.
Since @Tim77 wants to avoid adding an amplifier and wants to output monotones of notes of a musical scale, I think that Pmod AMP2 better matches the requirements than Pmod I2S2.
BTW. It would be interesting to check the sound quality of Pmod AMP2 in combination with the second order sigma delta modulator from this project.