mvneufeld
100+ Head-Fier
Thought I should mention that the green card in that pair of photos is not a newer version of the OG card after all. It's a 2/64. https://www.head-fi.org/threads/schiit-audio-bifrost-2.914084/post-17570818The more interesting part is on the top right of the boards as pictured. On the older red board (BFM3) there's a TPS7A39 LDO for voltage regulation. It's got a PSRR (higher is better) of 69 dB at 120 Hz and over 50 dB from 10 Hz to 2 MHz. Output voltage noise (lower is better) is 21 μV(rms). The newer green board (BFM4) has got a more discrete implementation with two LT1236 voltage references controlling two separate FETs. Now typical output voltage noise is 2.2 μV(rms) and PSRR over 100 dB at 120 Hz, linearly decreasing to 60 dB at 10 kHz.
TL;DR: the new voltage regulation section is over 10x better and the caps shouldn't matter.
Probably does contribute to the more linear sound of the 2/64 card.
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