One of the concerns about upgrading to higher end gear is how long the equipment can stay viable in this day of rapidly changing technology. Buying an amplifier or speakers is usually a pretty safe investment, as those technologies change relatively slowly.

Additional Resources
• Read more preamplifier reviews on HomeTheaterReview.com.
• Find a receiver to integrate with the AVM-20.

Buying something like a surround sound processor is a completely different animal, as the changes that we have seen in formats have been dramatic over the past few years. In fact, the digital front ends of surround sound processors (SSPs) have essentially become mini-computers, running processors at speeds that far exceed those of my first computer (anybody still remember the Atari 800?). It follows to reason that it is possible to make SSPs that are upgradeable to prevent them from becoming rapidly outdated. Upgradeability has been a feature of some ultra high-end products, but it is not until recently that this concept has worked its way down to more affordable products. Anthem has created just such a product in the remarkable, reasonably priced Anthem AVM-20. Just introduced before the latest Motorola processors became available last summer, the Anthem has since hardware and software upgraded to add a list of goodies including the all-important Pro Logic II, and the moniker "Version 2.0" has been added. In fact, parent company Paradigm's customer service has been so instilled in Anthem that these guys cruise the Home Theater Forum to look for problems that people are having so they can solve them. As a result, the Anthem AVM-20 thread has become one of the longest threads on that forum. To me, it is a significant statement about a company when they are so receptive to the feedback of us demanding audiophiles.

Unique Features
Going down the feature list reveals such goodies as 100 MHz component video switching (good enough for 1080p video switching), 3 zone capability, an AM/FM tuner, center channel equalization, and the latest surround decoding modes (Dolby Digital EX, Pro Logic II, DTS-ES, and THX Ultra 2 post-processing). Furthermore, the case for this processor has been strengthened by the aforementioned steady string of updates, including a hardware upgrade that incorporated the new Motorola processor only costing $300.

The AVM-20 is available in both black and silver machined aluminum faceplates. Both have chassis cases in simple black metal, so as much as I liked the lustrous silver faceplate of my review unit, I personally found the disconnect to the black case to be a little off-putting. This matters little when placed in a rack, but those who don't use one may want to consider the more integrated but slightly less avantgarde look of the black unit. The front LED display is unique in that it is large, legible, and provides a significant amount of information at any given time, which is a combination of traits that are altogether too rare on SSPs.

Installation/Setup/Ease of Use
Turning to the back of the unit reveals an enormous amount of flexibility. The AVM-20 is equipped with balanced outs for all channels, a set of balanced analog bypass inputs, and 7.1 RCA analog inputs for outboard decoders. Component video switching is provided for 2 sources (although I really wish it was for 3), and there are seven S-Video and composite inputs. The AVM-20 uses a system of set digital coaxial inputs and S-Video/composite/RCA analog inputs. This is a very straightforward system that is easy to understand, but provides a little less flexibility than the completely assignable inputs of my reference Krell Showcase Processor. Still, many of my friends prefer such a system as being more user-friendly (you don't have to sit there are write down a list of what is hooked up to which number source). The TosLink digital inputs, AES/SBU digital input, and the three relay triggers are freely assignable. An RS-232 port is used for performing software upgrades.

The included learning/pre-programmed remote is very nice, with a rubberized matte finish that I found comfortable. The backlighting is in blue--a very attractive touch which is easy on the eyes in a dark room.

The setup menus, as you can imagine, are extensive due to the exhaustive list of features. Overall, they are fairly easy to use, and the included manual is easy enough to understand. Any input source can be assigned to have the audio input via the analog inputs without processing, through the analog inputs with processing, or from the digital inputs. The one quirk of this system is that it does not automatically migrate to a digital input if it becomes active when both it and an analog input are plugged in. The folks at Anthem tell me a fix is on the way for this in the next software upgrade (along with a host of other upgrades, many of which answer issues raised on the Home Theater Forum AVM-20 thread). Since this system also functions for the analog 7.1 inputs, it happens that the Anthem will perform DSP processing such as bass management on these inputs. Very handy, especially since bass management is rudimentary at best in most SACD/DVD-Audio players.