산스이 @시리즈 TU-X701 튜너를 사용 중입니다.
그런데 처음에 전원을 넣으면 스테레오가 안됩니다;; 모노로는 잡히는데;;
한 시간 정도 켜 놓으면 그 때서야 스테레오가 잡히네요;;
이런 경우 보통 어디가 문제일까요?
그리고 내부에 op앰프 2043이 하나 달려있는데, 이걸 BB opa 2604 같은 좀 더 고가의 op 앰프로 교체를 해보려고하는데 괜찮은 시도가 될런지 궁금합니다.^^
참고하시라고, 아래 일본어 페이지 번역된 자료 링크와, 영문 평 자료 입니다.
Sansui TU-X701 (1987, $550, photo1, photo2, inside, brochure) search eBay
The very rare TU-X701 is a small black digital synthesizer AM/FM tuner with an orange LED display. It has selectable IF bandwidths with a decent front end that uses an RF attenuator. The IF strip uses 10.7 MHz transformers to tune GDT ceramic filters for optimum distortion performance. Sansui claims that the TU-X701's "SLDD" (Super Linear Digital Decoder) eliminates spurious frequencies. Our panelist Bob points out that the TU-X701 uses the LA3450, the multiplex chip version of SLDD, fed by a PLL-type detector. Our contributor Ryan says: "On the whole, this design has the right elements for good sound. And Jim's review is right, it can sound very good, but I did not care for mine just out of the box. I finally measured my unit, and saw very high THDs, but with very minimal adjustment, measured performance improved dramatically. Fortunately, this also helped the sonics tremendously, and it is now one of my better post-alignment tuners as well. This just goes to show you that proper adjustment is always critical! The TU-X701 is certainly a bargain tuner given the top-notch design and sound." Our contributor Warren M. agrees: "After alignment and replacement of some aged components, my TU-X701 sounds very nice and has the lowest stereo noise level of any tuner I've ever heard." Our contributor Hank A. "wasn't impressed with the sonics of the X701" as-found, but didn't try getting it aligned.
Our panelist JohnC compares the TU-X701 and its successor, the TU-X711, to the Denon TU-800: "According to the service manual the X701 and X711 are identical tuners, circuit-wise, with only cosmetic changes between the two. There is a remarkable similarity between the X701/711 and the Denon TU-800 from the LA1235 IC to the LA3450 MPX chip. Both bypass the internal quad detector and implement an external discrete one. The Denon is double-tuned while the Sansuis are single-tuned. Both use a 2043 op-amp in the composite signal path and both feed an LA3450. From the LA3450 out the Denon seems to have a much more direct/cleaner signal path and buffer. The X701 and X711 have 4 ceramic filters: CF1 and CF2 are SFE10.7MX filters which I believe have a 250 kHz bandwidth, and CF3 and CF4 are SFE10.7MS2 filters which are 230s. Having gone through both tuners, the Denon is the better of the two for both DX and sound. Just my $.02." Read our panelist Jim's review and see how one TU-X701 sounded compared to other top tuners on our Shootouts page. The TU-X701 usually sells for $260-325 on eBay, with a low of $102 in 9/08. One that was outrageously hyped ("today the best tuners use newly developed Satellite Technology to pull and strip the signal out of the air") sold to a novice eBayer for $377 in 5/04. [JR]