Confused by ICE applications


I've started to get interested in the switch-mode power supplies, but I'm confused by how the various amplifier makers use them. My current investigation is into the B&O ICE modules and Jeff Rowland amps.

From what I can see on the ICE web page, they only sell complete amplifier modules. If that's so, what does JRDG (or Bel Canto) do with them? I'd thought that ICE would supply the power supply and the output stage was then up to the end user...
128x128macdonj
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
According to one of the editorial reviews (can find it) Bel Canto's S300 suffers thin lower midrange but after placing it on anti-resonance cones sound becomes fuller. Rowland's case is milled from billet of aluminium.
In fact, on the Continuum the large flat surfaces of the chassis are ridged, to refract sound waves in those cases where it might be close to speakers. The tolerances on the Rowland chassis are .003". The nibs and screw threads for mounting boards, etc. are machined in, to the same tolerance. Like I said before, the Rowland chassis is no mere cosmetic design exercise, even though he highly values esthetic appeal.

Dave
Dave,

Thanks for the report on JRDG equipment. I knew from past reviews that Jeff pays attention to things like case design (Stereophile made special note of it in their review of the Model 2). However, I've never been able to look into one of his components and the "official" web is mum on the modifications and particulars of the application of the ICE units. So, thanks again for spelling it out, that's exactly the information I was looking for.
A few yrs back, I bought a few Acoustic Reality ICEPower monoblocks to drive my then Revel Salon.

The ICEPower monoblocks made me sell my Mark Levinson No.33H that I used to drive the Salon.

ICEPower is simply fantastic.

I now use a DarTZeel but kept all my Icepower stuff...I plan to build an ICEPower based HT...

btw, anyone know how the new ICEPower modules compare to the older ones? The new ones supposedly has much higher current then the older generation... but what else?