www.bandwidthaudio.com - First video of our phono preamp design progress. After a few months of tweaking and testing various designs, our prototype is shaping up quite nicely! This preamp is Class-A open loop with quite amazing THD and noise performance. The gain is 47dB. I do not have the RIAA filter installed yet. I was tuning all of the stages first without the EQ network. To get the correct gain, I have a 20dB voltage divider between the first and second stage. Without this divider the gain of the preamp is 67dB. Output noise is 68uV A-Weighted for an input referred noise figure of 0.3uV I expect this to be even better with the RIAA filter due to additional high frequency attenuation.

свернуть