Digital Processor Reviews

Adoption of DSP-based speaker-and-room correction in home theater—a parallel universe to audiophilia—is almost universal. It's easy to understand why. Home theater matured in the digital age. Its fans were expected to install several loudspeakers in a full-range setup that included at least one speaker—the subwoofer(s)—that functioned exclusively in the problematic bass region. Setup issues were intimidating.

Imagine an electronic magic wand you could wave at your listening room's acoustical problems to make them disappear. The Cambridge Signal Technologies SigTech TF 1120 may be just such an alchemical device. Its efficacy depends on the nature of the acoustical warts in your listening environment. Operating solely within the digital domain, the SigTech device can perform both drastic and subtle frequency-response and time-domain corrections that are beyond the scope of analog-based units. While the TF 1120 is expensive, in some situations it may still be the most cost-effective way of coping with acoustical gremlins. Is it the solution to your problems? Perhaps.

We hold these truths to be self-evident, that all men are created equal.

A great concept—sound enough to serve as the foundation for an independent democratic nation.

Yet what's sound in one sphere doesn't necessarily apply to sound in another, namely the rooms in which our systems reside. As much as we audiophiles may wish to declare our independence from room resonances, image smearing from first-order reflections, slap echo, and every other environmental and speaker-related factor that can handicap system performance, no mere declaration will make it so. Not all rooms—and not all components—are created equal.

I have owned the SE version of the Bricasti M1 D/A converter for several years. It's my reference DAC. When, recently, I became aware of the availability of the factory-installed MDx Processor Board upgrade, I packed up the M1SE and sent it off to the Bricasti factory, which is in Shirley, Massachusetts, northwest of Boston. The factory-installed MDx upgrade costs $1000—a lot less than the $10,000 it costs today to buy a new M1SE with the MDx board.

As ALF would say, "There's more than one way to cook a cat." We've been so overwhelmed with linear pulse-code modulation (PCM) recording, we forget there are other ways to pass from the analog domain to the digital.

One of these is delta modulation. The Greek delta (which in its upper-case, block-letter form, looks like an equilateral triangle) is the mathematical symbol for the difference between two quantities; accordingly, in delta modulation, we record not the absolute value of a signal sample, but the difference between successive samples.

With the furor over the launch of DAT (digital audio tape), it is worth remembering that commercial digital recorders have been with us for some time now: it is now nearly a decade since studio PCM converters were first successfully used for audio recording in conjunction with a VCR (which uses a helical spiral recording via a spinning drum to achieve the high writing speed).

I have reported on exaSound DACs since the introduction of the e18 in 2013, but those reports were in my Music in the Round column. This is Stereophile's first full review of an exaSound product and the first time one has spent time on JA's test bench.