STEREOPHILE GUIDE TO HOME THEATER

TAG McLAREN AV32R                                      By Steven Stone

When I found out I was getting a TAG Mclaren product for review, I mentally cleaned out my non existent garage and found a resting place in my top bureau drawer for my new Rolex. But when UPS finally arrived delivered, I was disappointed: The box was too small for a car, too large for a wristwatch. My discontent abated soon after I opened the box, however, for inside was a very suave and stylish A/V preamp. The AV32R looks as if it can not only keep perfect time, but go from 0 to 60 in microseconds. Please attach your shoulder harnesses; we’re going for a ride.

Under the Hood

The TAG McLaren AV32R was designed and built by the same folks who developed the electronic control systems for the TAG McLaren Formula One racing cars. Dr. Udo Zuker, who heads up TAG’s audio division, points out that “There are many immediate spin-offs into audio from our expertise in automotive electronics, mechanical engineering, and the material science of Formula One motor racing: multi-layer printed circuits, fast digital signal processing, electronic noise suppression, radio-frequency technology, and software expertise, to name but a few.”

Instead of using a off-the-shelf integrated DSP chip, TAG chose Analog Devices’ new 

66MHz ADSP-221065L SHARC digital signal processor, and wrote their own proprietary code for it. Not only is this chip more powerful than other, more readily available chips, but it can be reprogrammed via software upgrades through the TAGtronic communications bus. Another innovation is the TAGtronic sync Link, which uses a standard RCA-type connector. Its sole function is to allow the clock in the primary D/A inside the A/V processor to control the timing of the datastream from the source – like TAG McLaren’s CDT20R CD transport, or the forthcoming DVD32R DVD player.

The THX Ultra-certified AV32R supports all current home-theater sound formats, including Dolby Digital, Dolby Pro Logic, THX Cinema, DTS digital surround, and MPEG-2. For 2-channel music sources it offers Direct and Direct Plus Subwoofer, though despite what the word “Direct” might imply, in all cases analog sources are converted to digital at the AV32R’s inputs.

There is also a special TAG McLaren surround mode that uses the center, rear, and subwoofer speakers to supplement the original recording ambience. Even 2-channel, 24-bit/96kHz digital sources can be processed through this mode.

Unlike the Lexicon MC-1, which handles 24/96 sources via special direct inputs that bypass the system’s crossover settings, the AV32R can accept 24/96 sources through any of its digital inputs and process them like any other input. The AV32R’s SHARC processor allows 24-bit digital signals to be handled just as easily as 16-bit signals, and 96kHz sampled sources as easily as 44.1kHz.

Analog sources are transmuted into the digital domain by a 20-bit/96kHz, 64x-oversampling, multi-bit delta-sigma A/D converter. On the back end there’s a 24/96, 128x-oversampling, multi-bit delta-sigma DAC. Perhaps TAG should patent the term Digital Horsepower “R” Us.

Inside the AV32R is all sorts of stuff to send the slide-rule set into heavy heart palpitations. A Siemens 16-bit C161RI microcontroller manages the monitor and control functions. A twin-phase-locked-loop digital clock reduces internal jitter. On the analog side, instead of the traditional method of using capacitors to block DC, TAG uses a feedback circuit to eliminate DC offset voltage. The AV32R’s analog signal path is direct-coupled, bypassing any capacitors that might limit low-bass response. A large toroidal transformer steps down the power line voltage, and Elna Cerafine bulk decoupling capacitors control 15 individual power supplies. (Traditionally, we think of a power supply as a transformer, rectifier, and the associated filter capacitors. Today, manufacturers frequently use a single transformer with various taps to feed multiple rectifiers/filter cap stages, each optimized to power different part of the circuit. They then refer to these individual rectifier/cap sets as separate supplies, though they all share the same transformer.)

The power supplies have three levels of filtering: First are the Cerafine storage caps near the linear regulators, then slightly smaller caps closer to each device, and finally surface-mounted polymer electrolytic caps right next to each supply pin. High-quality Vishay metal-film resistors and Wima polypropylene capacitors are used throughout the rest of the AV32R.

Both surface-mount digital components and conventional, lead-mounted components are used on the AV32R’s multilayer printed circuit board. High-precision placement robots in a special nitrogen-filled, infrared reflow oven attach surface-mount components to the gold-plated, glass-epoxy PCB to reduce oxidation in the solder joints. This method also eliminates the need for nasty, environmentally unfriendly solvents. The leaded components are hand-soldered in a separate factory about 50 miles away by humans breathing oxygen. To ensure maximum vibrational attenuation, the AV32R’s cover and baseplate are bonded with a visco-elastic laminate, and the unit sits on multi-part Sorbothan support feet. According to TAG, these treatments provide at least 40dB of vibration reduction at 1kHz.

First Pit Stop

If you purchase an AV32R, don’t let anyone else open it first – part of the TAG McLaren  experience is the packaging. You gotta admire a company that cares enough about first impressions to use black plastic foam instead of the ordinary white stuff. The top layer, in which all the small accessories are artfully displayed beneath clear plastic shrink-wrap, fits over the preamp itself, which is cradled in two more custom-fitted pieces of black plastic foam. I’ve never seen a more precisely packed product.

The instruction manuals are not only well-written, but brilliantly packaged in two CD-style jewel cases. Instead of rummaging through drawers or shelves to find the instructions, you can store them right next to your CDs, ready at a moment’s notice to inform you about some arcane feature. Also standard is a TAG McLaren F3 pin for your jacket lapel. When you wear it, other TAG owners can identify you and greet you with the secret TAG handshake.

TAG McLaren is especially proud of their Setup Wizard. This isn’t some wizened old guy in a funny hat, but rather an oncreen display (OSD) that holds your hand as it walks you through each step of the setup process, and makes written instructions largely superfluous. Of course, you have a choice of Large or Small speakers. You can also set speaker distances in meters or feet, choose 50, 80, or 120Hz crossover points, specify whether or not you’re using a subwoofer, set output levels via an internal signal or your own source, designate default processing modes for each input, change input names, adjust analog source sensitivities, institute a DTS source-detection delay (to eliminate the brief burst of noise that might otherwise occur before the processor recognizes the source as DTS), specify your audio/video links, situate the OSD location, change the front-panel display brightness, and add a personalized message, like “DON’T BOTHER ME NOW.”

As you might expect, given all this technological tutelage, setup was easy and glitch-free. I encountered only two problems: If you turn off a digital source while in Setup Wizard mode, you won’t hear any internal test tones for level setting. So don’t do it. The other problem is that Setup Wizard is available only as an OSD – during setup, the front panel doesn’t tell you squat. If you have a CRT projector in a room that’s brightly illuminated by the sun during the day, you’ll have to wait till dark to do your setup. This won’t be a problem for the many videophile vampires in the audience, but it sure was inconvenient when I needed to tweak my setup during daylight hours.

While not all controls are available on the front panel, most are, which is convenient for those of us who tend to occasionally misplace the remote control. Front-panel controls include four input buttons labeled Analog, Digital, Video, and Tape. Four mode buttons are marked Surround, THX Cinema, Mute, and Display. The four balance buttons are arranged in a diamond, and four status LEDs are designated Auto detect, Balance, Mute, and Tape. (Is there a quadratic pattern here?) Finally, there’s a large LED display, an easy-to-grab volume knob with steps in 0.5dB increments, a remote-control LED that blinks when you send a command, and a circular On/Off power button.

The remote is made by Universal Remote Control, probably the most prolific independent manufacturer of such devices. It not only lights up, but allows you to program in commands for other components – like your DVD, LD, or CD player, TV, VCR, or satellite dish. The remote can also hold four macros, or combinations of key-presses, which can do up to 10 things in a row. This is perfect for technophobes: Just preprogram a macro “ To watch a movie, press m1.”

I’ve used this remote before, so the learning curve was minimal. My principal complaint: It’s hard to read the input source labels in low light, because the buttons which do light up) have no information on them. And it’s very easy to push the channel-adjustment buttons instead of the volume buttons, as they’re adjacent and exactly the same size. The infrared acceptance angle and sensitivity are good enough that most of the time you can bounce the signal off a screen or front wall and it will still reach the AV32R. While the processor has an LED that winks in response to a command, you have to be looking at the AV32R to see it.

Some A/V processors are intimidating to adjust. The EAD TheaterMaster, for example, forces you to go into setup mode if you want to change the subwoofer level or the front-to-rear or side-to-side balance. The AV32R is quite user-friendly in this respect. If you want to change the balance or sub levels, you can do so from the remote without having to worry about whether you’ve pressed the right sequence of buttons. The display informs you of just how much of a change you’ve made, and there’s even a Normal button to return everything to the original, calibrated settings when you’re finished mucking about.

Such ease of use reminds me of the Lexicon MC-1, which also allows for quick changes to the standard levels and balances. The AV32R is not as versatile as the Lexicon or the Meridian 561, both of which allow you to perform extensive changes to each audio mode, and even create music and film modes of your own. The AV32R has only one surround music mode, and it can’t be specifically tweaked. TAG’s designers seem to have opted for simplicity.

During everyday use, the AV32R worked with very few glitches. The only amusical sounds were an assortment of clicks that accompanied any changes in audio mode. Especially when a DVD went through the cycle from Menu to Setup to Play, the AV32R emitted as many clicks as a Geiger counter in a uranium mine. Once a particular mode was finally established, it was quiet again. While I understand that it’s not a bad thing to hear single click when you change listening modes, it would be nice to be able to turn off this “feature” when going through a DVD’s Menu and Audio setup.

Road Test

If you want to quickly earn respect in the big leagues, hit a home run your first time at bat. The AV32R did nearly that – it proved an excellent sonic performer with an exceedingly low noise floor. Even with my ear right next to the Dunlavy SC-VI’s tweeter and the AV32R turned up to +15db, I heard only the faintest hiss. It was quiet as any A/V preamp I’ve had in my system.

Overall, the AV32R’s sound reminded me of the Lexicon MC-1’s similarly no-nonsense sonic signature. There seemed to be no attempt to prettify the sound. Instead, it was straight, with no sweetening. Like the Lexicon’s, the TAG’s low end was extended, but with no extra midbass weight or lower midrange bulge. Such an austere harmonic balance did little to warm raw, hard-edged mixes. Compared to the EAD TheaterMaster, the AV32R sounded a bit lean, but the EAD is easily the most lush, most “musical” A/V preamp I’ve heard. Luckily, the AV32R has a THX switch; you can roll off the top end on your nastier discs. Without the THX switch engaged, the AV32R had exemplary high-frequency extension and air. Little atmospheric effects – like the crickets and night noises in Double Jeopardy as Libby breaks into the kindergarten at night – sounded remarkably real.

Fortunately, even with sources as harsh as the Detroit Rock City soundtrack, the AV32R added no electronic grain, no subsonic electronic hash. On good material, like my live concert recordings, the TAG did a superb job of preserving spatial cues. Only the very slightest amount of depth was lost when compared to a directly bypassed signal. Soundstage width was the equal of the Meridian 561 and Lexicon MC-1, and ever so slightly smaller than the EAD TheaterMaster Signature. Lateral focus was particular precise through the AV32R.

With only one dedicated music surround mode from 2-channel sources, the AV32R was not flexible as the Lexicon MC-1 or Meridian 561, each of which possesses multiple options. I did find the AV32R’s TM (TAG McLaren) music surround setting more useful than the EAD TheaterMaster’s music surround mode, as it was easier to fine-tune. With a bit of adjustment to the rear-channel levels, the AV32R could produce subtle, convincing multichannel music from well recorded 2 channel sources. Chamber music and live jazz recordings especially benefited from the AV32R’s ministrations.

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