Macdonj, on the 312 and Continuum 500 one huge difference is the addition of Power Factor Correction. ICE and D can really spike the mains and cause harmonic currents that can be audible. The PFC presents a more sinewave-like load to the mains and eliminates the harmonic currents. Additionally, the PFC converts AC to 385 volt DC, giving ample, clean power to the unit. The DC operation also helps with quietness of the pre-amp stage, approaching battery power style low noise levels. (PFC can be added to most current JRDG products with his PC1 unit).
Add to that, dual-mono, fully balanced operation for the Continuum, short signal path lengths, heavy aluminum billet chassis, internal and external isolation from EMI and RFI and you end up with a total package that's beyond most of the competition. Jeff pays attention to each wire, trying different materials to arrive at what he considers the truest (most transparent) sound.
Jeff's chassis alone adds significantly to cost (even on the lower level 102, 201, 501 and Capri), but they aren't just things of beauty. They're functional parts of the RFI/EMI control scheme. With ICE and Class D this is very important because of all the energy given off by the unit itself. Combine that with a nearby CDP and it gets very important. My Continuum 500 and Playback Designs MPS-5 CDP are right next to each other in a tight armoire, with a gaggle of wires cramed in behind them. Despite all that potential, the system is almost dead quiet.
Jeff creates very elegant designs. Look inside his Capri preamp and you'll be amazed at how view circuits there are how clean things are. His phono modules are the size of the last joint of my little finger, yet they compete with Levinson, Sutherland, Manley, etc. for resolving capacity. The phono circuit is utterly quiet in my setup.
Clean and simple is a core philosphy to Jeff. He lives by that and it pays off in the results.
Dave
