I just exchanged my Audio Research amp, preamp and cd player for tube stuff. My D300 amp powered my B&W 702-S2 speakers wonderfully! I am 80 and used to sell high end audio and always wondered how a tube amp. pre amp and cd player would sound. Well, many thousands later I can only say the tubes seem warmer. My Audio Research D300 amp is now for sale to someone who wants a wonderful experience. Below is a glowing review of the amp.All the lines fall on top of each other indicating the amp just doesnt care what frequency you feed it. It amplifies it, adds a heap of distortion and that is that. Makes you want to cry and celebrate at the same time!ConclusionsThere is clear excellence in the engineering in Audio Research D300. Build quality is superb as well. There must have been a conscious decision to use low amount of feedback which translated into rising distortion with power. It is a shame that capable designers follow audiophile myths to build non-performant amplifiers when they could do so much better.In this day and age, this type of performance is not competitive so I really cant recommend the D300. Then again if you want something with high build quality and can get the unit on the cheap, it makes for a decent option.

I just exchanged my Audio Research amp, preamp and cd player for tube stuff. My D300 amp powered my B&W 702-S2 speakers wonderfully! I am 80 and used to sell high end audio and always wondered how a tube amp. pre amp and cd player would sound. Well, many thousands later I can only say the tubes seem warmer. My Audio Research D300 amp is now for sale to someone who wants a wonderful experience. Below is a glowing review of the amp.All the lines fall on top of each other indicating the amp just doesnt care what frequency you feed it. It amplifies it, adds a heap of distortion and that is that. Makes you want to cry and celebrate at the same time!ConclusionsThere is clear excellence in the engineering in Audio Research D300. Build quality is superb as well. There must have been a conscious decision to use low amount of feedback which translated into rising distortion with power. It is a shame that capable designers follow audiophile myths to build non-performant amplifiers when they could do so much better.In this day and age, this type of performance is not competitive so I really cant recommend the D300. Then again if you want something with high build quality and can get the unit on the cheap, it makes for a decent option.