Spectral DMA-400RS = Class A or Class AB?


New Member
Jun 3, 2013
May I know if Spectral DMA-400RS is Class A or Class AB amp? It can't find this information from internet. Thanks.


Member Sponsor & WBF Technical Expert
Jun 23, 2010
Monument, CO
AB. Quiescent current consumption is too low for full class A, though high enough that it probably runs class A for 25+ W, more than enough to provide a goodly amount of low-level detail without crossover distortion.

HTH - Don


VIP/Donor & WBF Founding Member
May 6, 2010
Boston, MA
Don’t really know but would tend to agree. At the same time though, there is also sliding/servo bias.

Al M.

Sep 10, 2013
Greater Boston
I am not sure it really matters. One can argue theoretically back and forth, but in the end the practical implementation is what decides. And Spectral is probably among the best and most impressive implementations of solid state technology out there.

My Octave tube amp features both pentode circuits and class A/B mode, both concepts being anathema to some tube lovers. But the implementation and resulting sound are excellent, so I don't care. I did upgrade to the Octave from triode class A monoblocks.
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