Yamaha DSP-A1000 AV amplifier
Back in 1986, Yamaha introduced what was probably the very first home digital sound-field processor, the DSP-1. Yamaha's engineers had measured the acoustical characteristics of a wide variety of concert halls and other establishments where music was performed. Then, using digital signal processing and large-scale integrated circuits, they stored these characteristics in their first sound-field processor so that the environments could be duplicated in a home listening room. Yamaha's newest processor, the DSP-A1000, combines the company's latest digital processor circuitry with a seven-channel integrated audio/video amplifier. As I quickly learned, it also employs the most sophisticated digital sound-field processing and home theater surround-sound circuitry Yamaha has ever offered. The DSP-A1000 features 12 different sound-field programs and 23 variations, including separate modes for general and adventure movies. Utilizing a combination of digital processing and digital Dolby Pro-Logic to create a "70mm Movie Theater" setting, this all-in-one unit provides separate sets of information for foreground voices, special effects, and music and surround channels. In the seven-channel mode, dialog and front action are fixed at the video screen, while the effects are enhanced in the four available surround channels. A conventional Pro-Logic five-channel configuration is possible, as are four-channel arrangements (substituting a "phantom" channel for the preferred center-channel speaker) and even minimal three-channel installations.
The fixed sound fields are not limited to use with video sources. For music-only enjoyment, three different concert hall settings are provided (with two variations apiece)-as well as a church environment, two types of rock concert environments, and modes for disco, jazz, and stadium. Audio/video DSP programs include "Concert Video," "TV Theater," "Movie Theater," and, of course, the normal and enhanced modes of Dolby Pro-Logic.
The two main amplifiers and the single center-channel amp are designed to deliver 80 watts per channel into 8-ohm loads; the four effects channels provide 25 watts each into 8 ohms. (Part of the DSP-A1000's substantial weight of 44 pounds is attributable to the massive transformer employed in its power supply and to the anti-vibration, antiresonance chassis.) In addition to supplying high power levels, this unit incorporates 10 audio and five video inputs with S-video as well as composite video jacks. Front-panel auxiliary terminals (including another S-video terminal) are provided so that you can connect the outputs of a camcorder without having to access the rear panel of this amplifier. A motor-driven input selector can be operated at the front panel or via the learning-capable remote control supplied with the DSP-A1000. A separate record-out selector lets you send any signal to "VCR 1" or "Tape 1" while another program is being heard or viewed.
The DSP-A1000 includes a digital test-tone generator for DSP and Dolby Pro-Logic, five-band center-channel equalization, three center-channel modes (normal, wide, and phantom), and normal and three-channel Pro-Logic modes. Information that appears on the multi-function display on the front panel can also be superimposed on the screen of your TV monitor, if it's connected to the Yamaha's rear-panel "Monitor" output jack. Additional features of this amplifier include bass and treble tone controls, a preamp-out/main-in jack set, a subwoofer output terminal with a low-pass filter, dynamic "Bass Extension" (which I'll discuss later), audio muting for the main and effects channels, and a front-panel headphone jack.
Control Layout
The upper half of the all-black front panel houses the main power switch, a "Tape 2 Monitor" switch, the rotary source selector, and the master volume control (which is calibrated in dB from full volume, "0," past -80 to "-∞"). The centrally positioned LCD display area shows selected program names and parameters, information about other various settings and adjustments, and activation of the Pro-Logic and sound-field processor circuits.
Lowering a swing-down hinged panel reveals additional controls. These include an "Input Trim" control that adjusts input levels of each program source and also adjusts items selected by an adjacent "Set Menu" switch. That switch in turn brings up five different items for adjustment: "Pro Logic Mode," "Center Mode," center graphic equalizer, "Sub Woofer Level," and "Color" of the TV picture background (when no video signal is being applied to the connected TV monitor). A "Program" switch sequentially selects the sound-field processing programs, while an "Effect" switch turns effects speaker channels on or off. Other controls normally hidden by the swing-down panel are the stereo headphone jack; a "Bass Extension" switch; bass, treble, and balance controls; a "Rec Out" selector, and a set of audio and video auxiliary input jacks, including an S-video connector.
In addition to duplicating almost all of the control functions found on the front panel, the supplied infrared remote offers buttons that adjust rear- and center-channel levels relative to main-channel levels, change on-screen display parameters, and operate such other compatible Yamaha components as a CD or LaserDisc player, a tuner, and a tape deck. The remote can, in fact, be "taught" to control components from other manufacturers as well. Each key can learn two different functions, selected by flipping a switch from memory "1" to "2." Memory "1" is preprogrammed with functions that are called out on the panel, though it can be reprogrammed by the user. Memory "2" is empty, ready for user programming, and a blank template is supplied for personalized labelling.
When I turned the unit around to make my connections, it was easy to understand why the DSP-A1000 had to be more than 6,5 inches high: The rear panel is crammed full of jacks and speaker terminals. There are seven pairs of RCA jacks for audio-only program sources, the 24 RCA or S-video jacks needed for routing two VCRs and inputting a LaserDisc and a DBS TV feed, and a monitor output in both RCA and S-video. The panel has some eight sets of speaker output terminals (two main, four effects, and two center), a subwoofer output jack (for use with powered subwoofers or with a separate amplifier), and four "Effect" output jacks (for those who prefer to use separate amplifiers for surround channels instead of the built-in amplifiers). There are also jacks for interconnection of the preamp and power amp sections, in/out jacks for the center channel, and a "Mono" output jack (which Yamaha explains is for fill between widely spaced speakers in large rooms). A small "Main Level" rotary control adjusts the line output level at the "Main Out" jacks. A "Front Mix" switch allows effects signals to be blended into the main outputs for systems that do not use front effects speakers. A center-speaker impedance-matching switch, three a.c. convenience outlets (two switched, one unswitched), and a ground terminal complete the rear-panel layout.
Listening and Viewing Tests
There are so many ways to set up this sound-field processing A/V amplifier that I was delighted when three of Yamaha's staff volunteered to come to my lab and listening room to make certain I properly explored all aspects of this versatile component. I resisted at first, thinking that they might attempt to do a bit of "brainwashing" to make certain that I said nice things about the product. My fears were ungrounded. Armed with extra speakers, a laser videodisc player, and plenty of cables, the Yamaha crew took over my own home theater installation without in the least upsetting my own entertainment system, other than to use my reference front speakers as the main speakers of the system. To these, they added a center-channel speaker, perched atop my 32-inch reference TV monitor/receiver; a pair of front effects speakers (mounted high, and actually behind what I normally call the "front" speakers, but which they call the "main" speakers to avoid confusion); a pair of rear effects speakers, and a subwoofer. In sum, the installation now included a total of eight speakers, seven of which were being driven by the DSP-A1000! (The subwoofer was an active system.) In addition, they hooked up a Yamaha optical disc player so that we would not have to disconnect my own videodisc player from the rest of my system.
What followed can only be described as the most authentic concert hall and movie theater experiences that I have ever enjoyed in my somewhat cramped home theater listening room. Before I tell you about the impact of some of the motion picture excerpts I watched, let me describe what happened when I played a CD of Mozart's 40th Symphony (Telarc CD-80139) by the Prague Chamber Orchestra under the direction of Sir Charles Mackerras. (I felt that this was an appropriate starting point during this 200th-anniversary year of that sublime composer's death.) I began playback using the DSP-A1000's "Concert Hall 1" mode, a European hall that was not further identified. The room size seemed to expand to that of a moderately small hall, one that I deemed particularly appropriate for this Mozartean orchestra. When Gary Altunian, National Product Training Manager for Yamaha's audio component line, attempted to impress me with "Concert Hall 2" and "3," I felt that they sounded much too big for this Mozart recording, and he obligingly returned me to the smaller concert hall. I wanted to hear the entire symphony, but in the interests of time, I settled for just the First and Second Movements. I sensed that the Yamaha crew really wanted to get on with some demonstrations of blockbuster films.
The first clips we watched were from Indiana Jones and the Last Crusade. The scene in which Sean Connery and Harrison Ford fly (and crash in) a small biplane was first played using Dolby Pro-Logic. It was impressive enough as the heroes' plane was chased by the bad guys in another plane, with sounds streaming overhead and across my expanded home theater environment. Then I used the remote to switch to what Yamaha calls "Dolby Pro-Logic with enhancement," a mode that uses DSP to synthesize phantom images of the multiple effects channels in large movie theaters. Instantly, I was transported to a larger theater, one that made better use of the Dolby Stereo process. The scene now took on new, greater dimensions, with the sounds of the moving aircraft seeming to make smoother transitions from side to side or from front to rear. Finally, I used the remote to select the "Movie Theater" surround mode. There was suddenly an astounding increase in spatial depth. Sounds were coming not only from the actors (via the center channel) and from the space between the screen and my viewing position but also from "behind" the video screen. The contribution of those extra front effects speakers was particularly spectacular during the playback of the same scene in the "70mm Adventure" submode (which combines Dolby Pro-Logic with DSP circuitry); it simply has to be heard to be believed. With dialog at the screen position, sound effects in the near background, and music in the far background, this combination Dolby Pro-Logic/ DSP mode truly enveloped me in total surround sound in a way that I had not heard before except in one of the few large motion picture houses remaining in the New York metropolitan area. Certainly, the sonic experience was far superior to the level of sound quality I typically encounter when attending movie theaters that have been subdivided into multiple screening rooms!
The "Movie Theater" mode has a second submode, "70mm General," that is perhaps more appropriate for less dramatic, less adventure-laden films. It was extremely effective with romantic comedies, drama, and what I can best describe as "lower budget" films, but for the greatest impact, give me that "70mm Adventure" mode every time!
I'm indebted to Yamaha's Larry Poor, Marketing Manager for Audio Products; Frank Ricatto, Eastern. Regional Manager for Audio Components, and Gary Altunian. The reviewer's task with a product as all-encompassing and elaborate as the DSP-A1000 is not an easy one. I suspect that had it not been for their help, I might have overlooked some of the wonderful surround and sound-field capabilities of this processor/amplifier. As they were packing up the extra speakers and other components they had brought (leaving me the amplifier for further testing on the bench), I could not help but recall the first digital sound-field processor Yamaha introduced five years ago. That unit required the addition of several power amplifiers as well as the required number of speakers. Anyone brave enough to undertake assembly of a home theater or surround sound environment in those days ended up with a rack full of electronics-and a tall rack at that-before even considering the necessary extra speakers. That all of the electronics needed for the variations of Dolby Pro-Logic as well as the 12 programs (for 23 modes) of digital sound-field processing are incorporated in a single "do everything" component can only be regarded as a minor electronics miracle. That such a component carries a price tag actually lower than that of some processor-only components is an even more miraculous achievement.
