|IHF Sensitivity mono/stereo,dBf
||Seperation at 1kHz,dB
||THD at 1kHz,stereo
STEREO FM TUNER WITH ASYMMETRICAL CHARGE-COUPLED FM STEREO DETECTOR.
• Asymmetrical Charge-Coupled FM Stereo Detector.
• 13 Random AM/FM Station Presets.
• Multi-path Elimination Circuitry.
• Noise Reduction.
It dramatically reduces FM multi-path and distant station noise while providing stereo reception with space, depth, ambiance and full separation. The TX-11a also opens up whole new sonic possibilities through the incorporation of the world’s finest AM stereo reception section. AM signals sound as good as FM!
This system separates stereo into two different bands. But not just Left and Right like a cassette. Instead, one band is comprised of those parts of a stereo signal which are common to both channels (L+R, or mono); the other, those fragile differences between Left and Right (L-R).
When the (L-R) signal careens off buildings, hills, bridges and even large trucks, an extra signal arrives at your antenna, rather like audio ‘ghosting’. The result is not only scratchy reception, but rhythmic pulsing of the sound (called ‘beating’), plus a whole repertoire of rude sounds, as conventional tuner/receiver circuitry vainly tries to sort out the signals.
Not even the most expensive traditional tuner circuitry can conquer these problems. Because none of them approach a solution the way Bob Carver did.
Almost all noise and distortion is exactly 180 degrees out of phase with itself. In other words, for every instantaneous noise voltage, there is a replica in the opposite channel. The TX-11a’s Charge-Coupled circuit detects the tell-tale, dirty mirror images and cancels up to 85% of them before they reach you ears.
We weren’t satisfied, with merely 85% and knew that you wouldn’t be either. Another Carver development, the leading Edge Detector, goes a step further by taking advantage of the L-R signal’s remaining 15%. Operating on the critical 15%, the Leading Edge Detector filters out even more noise and reconstruct the stereo effect.
Len Feldman in Ovation magazine observed that the circuit, ‘… may well mean the difference between marginal reception of the station signals you’ve been yearning to hear and truly noise-free reception of those same signals’.
Audio Magazine called it, ‘An FM tuner breakthrough’.
Unfortunately, the AM sections in even many deluxe tuners have been given short shrift. They sound terrible because they are limited to frequencies scarcely higher than 3kHz, signal-to-noise ratios of only 30dB, and distortion as high as three to eight percent.
Only Carver offers the quality technology to fully take advantage of AM stereo’s hidden performance. The innovations include a unique de-emphasis circuit, pilot signal and whistle-stop canceling circuits, an ultra-low noise balanced station detector, and very wide band, minimum-phase intermediate frequency amplifiers. What all this means to you is simply true high fidelity AM stereo sound.
At a major press conference, Bob Carver unveiled this remarkable new design. To dramatically demonstrate the TX-11a’s AM stereo fidelity, he also unveiled an AM stereo broadcast source. This same CD player was also routed directly so comparison could be many between the direct signal from the CD player and the same signal being received by the TX-11a.
In front of America’s most respected audio critics, Bob switched back and forth between the transmitted signal and the direct signal. Many listeners had difficulty distinguishing between the two. Most could tell no difference at all.
If the TX-11a can receive AM that well, think of how well it will receive your favorite FM stations.
Engage the Auto Tune control, by touching the UP of DOWN button and let the TX-11a find each and every receivable station while displaying the signal strength of each with some pinpoint LEDs. Or manually advance across the AM of FM band with total precision.
When you find a station you want to regularly listen to touch MEMORY. It then entered one of 13 presets that allow you to select any combination of AM and FM signals. Select them in any order ‘on the dial’, and then recall them instantly. (If you don’t presently have 13 favorite stations, just wait until you discover how many more previously poor signals suddenly come in clear and hiss-free with at TX-11a). And remember, the TX-11a will remember all 13 presets even when unplugged for up to three weeks. In fact, it even returns you to the last station you were listening to each time you turn it on.
A Narrow Band FM setting eliminates bleed-through when strong stations are extremely close on the dial without lasing frequency response. Wide Band can be used when such interference is not a problem to receive slightly greater dynamic range.
While in AM mode, the ACCFM Detector controls double as a +12dB RF Gain Switch, which increases sensitivity of weak or distant AM stations, and a Noise Switch to eliminate periodic interference caused by fluorescent lights, thermostats, dimmers, etc.