This power DAC has local feedback on the PWM signal, this provides compensation for the influence of the power supply on the signal and compensation for nonlinear distortions created by the PWM amplifier. Measurements show that with a load of 4 Ohm and 100 W, this DAC has a noise shelf at -106 dB (A). Or SNR = 106 dB (A)
https://www.diyaudio.com/community/threads/3-way-dsp-amp.415065/
If we recalculate this noise level into microvolts, we get that at the DAC output we have a noise of 100 μV.
If we take a speaker with a sensitivity of 96 dB / W / m and apply a noise level of 100 μV to it, it will create a pressure at one meter equal to 7 dB (A)
If we take the background noise level in studios, which is 20 dB (A), then at a distance of 1 m you cannot hear the noise created by such a DAC. For the noise to become noticeable, it is necessary to have a difference of more than 10 dB. Simply put, the noise from such a speaker will be heard at a distance of less than 30 cm in studio conditions; a more precise distance can only be found imperially, since it depends on the size of the speaker diffuser.
https://www.diyaudio.com/community/threads/3-way-dsp-amp.415065/
If we recalculate this noise level into microvolts, we get that at the DAC output we have a noise of 100 μV.
If we take a speaker with a sensitivity of 96 dB / W / m and apply a noise level of 100 μV to it, it will create a pressure at one meter equal to 7 dB (A)
If we take the background noise level in studios, which is 20 dB (A), then at a distance of 1 m you cannot hear the noise created by such a DAC. For the noise to become noticeable, it is necessary to have a difference of more than 10 dB. Simply put, the noise from such a speaker will be heard at a distance of less than 30 cm in studio conditions; a more precise distance can only be found imperially, since it depends on the size of the speaker diffuser.
No hiss on the 3 examples I have. I’ve made an excellent pair of 3 way near field studio monitors using this amp. Can recommend
Ten 3Way DSP Amp boards available.
Five I/O boards with ESP32.
Five I/O boards without ESP32.
Four boards without ESP32 with pins for external I2S input.
Price.
One 3-Way DSP Amp board - $95.
One input board with ESP32 - $15.
One input board without ESP32 - $10.
One input board without ESP32 with I2S pins for connecting an external I2S source - $10.
Order more than one 3-Way DSP Amp board and get $5 off.
Payment via Payoneer electronic payment system.
Delivery to Europe and America is at my expense. Delivery to islands or other distant places is negotiated separately.
Five I/O boards with ESP32.
Five I/O boards without ESP32.
Four boards without ESP32 with pins for external I2S input.
Price.
One 3-Way DSP Amp board - $95.
One input board with ESP32 - $15.
One input board without ESP32 - $10.
One input board without ESP32 with I2S pins for connecting an external I2S source - $10.
Order more than one 3-Way DSP Amp board and get $5 off.
Payment via Payoneer electronic payment system.
Delivery to Europe and America is at my expense. Delivery to islands or other distant places is negotiated separately.