This review page is supported in part by the sponsors whose ad banners are displayed below

Amplification: 100wpc ModWright on top for the tweeter and midrange, 250wpc Wyred4Sound on the bottom for the two 15-inchers. That was the intended strategy. Dan Wright's KWA100 is a DC-coupled two-stage design with a FET-based class A voltage gain stage and class A/B biased current buffer running six power Mosfets per side. A small input transformer converts the incoming single-ended signal for dual-differential processing all the way to the outputs. A small concealed switch on the belly of the amp (front left corner next to the left footer) takes the KWA100 out of standby. This amp's feature review including its upgrade to SE status is here.

The ST-500 stereo amp from the Cullen Circuits team of Rick Cullen and EJ Sarmento is an ICEpower-based analog switching amplifier. It combines an SMPS with proprietary dual-FET DC-coupled and fully differential input buffers. Those increase the typical 8KΩ input impedance of the class D power processing boards to 61.9KΩ. That creates compatibility with valve preamps. The ICEpower boards meanwhile have their stock coupling caps bypassed without sacrificing DC protection. The feedback loops at the outputs are beefed up from stock to improve bass. The designers claim distinct sonic advantages for driving these popular B&O boards from dual-differential inputs. The intentional softening/smoothing action of the voltage-to-current conversion of their FET buffer is compared to a tube driver; albeit one that's direct-coupled and without the maintenance issues of real valves. This amp's feature review is here.

On cosmetics: The 26 Philips screws of the ST-500's painted cover mirror the industrial chic of the CS2.3s' back sides. The speakers' former grill socks have long since been abandoned to end up with field-serviceable units. In certain free-space installations like my former Chardonne residence, this leaves the driver baskets, magnets and wiring hanging out to trigger predictable complaints from interior designers. The obvious solution is to set up the Emerald Physics speakers conventionally a few feet from the front wall. Then the only possible view presented to an audience will be the burly Cherry faces with the big grills on top and the plastic ports on the bottom.
The ModWright amp meanwhile is a real looker. Those who don't care for its blue backlighting spilling out the top and through the frontal logo—home theater aficionados for example—can defeat it with a rear-panel switch. Like Wyred4Sound, ModWright offers both silver and black. As the upper photo shows, Wyred's silver is really a two-tone affair accentuated by black screw heads and corner pieces.

Clayton's NextGen: "We were transitioning to a next-generation software package which I anticipated to be ready sooner. Naturally we wanted you to evaluate the same system customers will be receiving, hence the long delay in dispatching the preloaded Mac Mini. Part of this next-gen software integrates an OEM version of Channel D's Pure Music. This further improved the sound and simplified our system for two obvious benefits in everyone's best interest. I had also been waiting for Channel D to add a few more feature details I'd requested. It turns out that Pure Music software designer Rob Robertson developed the first scanning/tunneling electron microscope* so for him this hifi gig is probably a walk in the park."
_________________________

* Actually, Mr. Robertson had a correction on this: "I did design and build the first working STM at Bell Communications Research (originally part of AT&T Bell Laboratories) but not the first in the world. That distinction goes to two of your fellow Swiss guys, Gerd Binnig and Heinrich Rohrer which caused them to win the Nobel Prize in Physics in 1986. But I did also design and build one of the world's first (if not the world's first) electrochemical STM in 1988."

Data acquisition: Half a year after I'd penned the introductory pages—this included moving house on my part—a Mac Mini with Dell screen and Apple Blutooth keyboard and mouse arrived. So did the TC Konnekt unit, all necessary 6.3mm-to-XLR interconnect cables between processor and the two power amplifiers, biwire speaker cables, a long custom Firewire link and a microphone with stand and balanced patch cord. As Clayton's IT contractor Charles found out who fielded the first setup phone call, the fire wall which my corporate service provider had configured for Motorola's DSL router proved undefeatable since I didn't have clearance codes. To gain remote access, Charles used TeamViewer* instead while asking me to network iMac and Mac Mini through the Motorola.


With the complete review system set up and live and the Mac Mini on line, Clayton's time had come. He emailed to make an appointment. We set up a day and time when he'd log on from his US location and run the measurement and calibration session in Switzerland while demonstrating over the phone how to use the computer interface.

__________________

The TeamViewer software generates an ID and separate password for each remote session. From your side granting Spatial access to your computer only involves launching TeamViewer and emailing Spatial the ID and password. Once the remote viewer logs off, the connection is severed. Any future session requires that you relaunch TeamViewer, then give your remote consultant the new password.

Enlarge!