Power Amplifier Reviews

You've probably never heard of a company called Wyred 4 Sound. Neither had I until I was offered the opportunity to review one of its multichannel power amps for UAV. W4S is a California-based company whose goal is to design, engineer, and manufacture high-end audio products with audiophile performance at affordable prices.

In addition, W4S is one of a growing number of companies that sells its wares only online, not in brick-and-mortar stores—which, I suppose, also helps keep its prices low. Can this company's approach to design and marketing actually result in superior value? Let's find out...

Features
W4S's Ice Cube MC (multichannel) series of amplifiers is available with a wide range of power levels, from 125 watts per channel to 500Wpc into 8 ohms (double that into 4-ohm loads). The amplifier used in this review was the 250Wpc 5-channel model.

Wyred 4 Sound chose the ICEpower engine for its power amplifiers (as did Pioneer for its SC-09TX, SC-07, and SC-05 AVRs). ICEpower was developed by Danish manufacturer Bang & Olufsen and is based on the concept of switching (Class D) power amplifiers. Rather than simply design the chassis around this power module, W4S claims to have significantly improved the module's performance with additional circuitry and modifications.

The details of how Class D amps work are beyond the scope of this review. Suffice to say this technology is far more efficient than Class A, B, or AB, allowing a Class D amp to be much lighter and run much cooler than the other designs. It also suffers from some inherent drawbacks that B&O seems to have overcome.

The amp includes RCA (unbalanced) and XLR (balanced) inputs for connection versatility, and each input stage has a dedicated, dual-filtered power supply with oversized, low-ESR (equivalent-series resistance) capacitors. The speaker binding posts are made of gold-plated solid brass, which can accept 4mm banana plugs, 6 and 8mm spade lugs, or bare wire up to 10AWG in size.

I tried using spade lugs, but I couldn't get any audio out of the front-left channel, probably due to poor contact. Switching to banana connectors eliminated this problem, so when the manual says that banana plugs are the preferred connection method, it isn't kidding. (According to the company, the binding posts have been upgraded and should now be compatible with any spade lugs.)

The amplifier's flexibility is enhanced by using a modular approach. Additional channels can be added in the future, and each multichannel amp in W4S's lineup can accommodate up to seven channels. In addition, the amp can be reconfigured at any time with different modules; the company charges the difference in retail price between what you have and what you want plus $200 labor.

The front L/R channels feature a selectable 80Hz, 12dB/octave highpass crossover for users who want to bi-amp their front speakers—the highpass channels are used to power the mid and high drivers. With a 7-channel configuration, you can bi-amp the front L/R speakers in a 5.1 system.