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RE: Solid State Power: MOSFET vs. Bipolar?

Posted by Maxamillion on October 14, 2010 at 06:22:49:
You know, I felt the same way until I recently made some changes to the low frequency EQ/buffer unit on my Infinity RSIIb speakers. I wanted to get rid of the output coupling caps so I changed the single-ended, class A MOSFET output unity gain buffer to an OPA827 opamp unity gain buffer (opamps of all things!). The extremely low DC offset of the opamp allowed me to remove the output coupling caps - the result was clearer, less congested sound, without introducing any harshness that I could hear. I'm starting to think that a properly implemented opamp (with enough PS decoupling/bypassing) can sound damn good. Perhaps it might be a different story in a gain stage.

The opamp buffer stage is on the tan board in the picture below (just below the board you can see the MOSFETs still in place, I left them in just in case the experiment was a flop).