Burson Buffers?

It worked on my midfi Onkyo CD changer. The Burson did provide a little more punch and a bit more clarity. For a player with the reputation of the 840C it's questionable if the Burson will be a detriment or a plus. It did not help my better players sound better. But the proof is in the listening.

The answer has everything to do with the output impedance of your 840C and the input impedance of your preamp (or integrated amp, or receiver).

If there is no impedance mismatch, then the Burson Buffer will not provide any improvement in sound.

The 840C User Manual shows an output impedance of less than 50 ohms. This is quite low, and will provide an excellent impedance match even with passive preamps.

I'm doubtful that a Burson Buffer would have any audible effect.

However, if you access to one without obligation, it's worth the experiment.

A friend and I compared the Burson to a Goldpoint stepped attenuator, using a 840C and Pass Monoblocks.

Even though the goldpoint was built with quality parts(silver wire, copper RCA jacks), the Burson had better transparency, dynamics, and extension on both ends. I would highly recommend it.