Pioneer CT-93 Cassette deck
The long-awaited Dolby S-type noise reduction (NR) system didn't get off to much of a start. When the first cassette deck with Dolby S-type NR, the Harman Kardon TD4600, largely due to reservations about the deck itself combined with a feeling of unease about Dolby S-type. It was a rather disappointing manifestation of a system in which so much time and effort has been invested.
But things may be looking up. A second manufacturer has climbed aboard the still very slowly rolling Dolby S bandwagon. Pioneer has introduced not one but two models, one of which - the CT-900S - is the cheapest Dolby S deck on the market at £500 (Harman's two decks cost £600 and £999), a position it should retain for at least, oh, five minutes.
The more expensive model, the £800 CT-93, is a development of, and replacement for, the well-regarded Pioneer CT-91 a standard cassette deck. It is a cost-no-object design, featuring a development of Pioneer's best dual capstan mechanism in which not only is tape tension and motion between the two capstans electronically controlled, but so too is the hub drive, improvements that on a lesser deck might well amount to nothing more than gilding the lily. The same mechanism is used in the 900S, but in a slightly less refined form. It almost goes without saying that both decks have three heads, allowing you to monitor the recorded signal a fraction of a second after it has been laid down on tape. Having three heads, each head dedicated to its own task, provides the opportunity for a better recorded sound, while also affording an instant A-B test, or comparison, of recorded sound with the source. Again, though, there are differences in execution, the CT-93 using more sophisticated head designs than the 900S.
The two Pioneers also have an automated system which adjusts tape record bias, equalisation and sensitivity (for Dolby replay tracking).
Make no mistake, both are extremely sophisticated cassette decks, a point made clear by the minor details as much as by the grander design. In both cases the transport is able to change mode and run in almost eerie silence. The loading door of each is powered and linked to the deck's micro-processor to allow instant recording, play or fast-wind with the door open, and safe tape unloading even if you don't first select stop. The display, though complex and informative, is easily read. It is even possible to switch the display off altogether. Powerful tape search aids include track search capable of finding tracks up to 15 away in either direction.
But there are important differences too, differences that extend beyond the superficial charms of the CT-93's deep gloss facia and lacquered wood sides and gold flashing. The more expensive deck also has a Remaining Time tape counter, a 'straight line' input which by-passes the balance control, as well as a manual bias, which can be tweaked after automatic alignment, a Dolby HX Pro switch and a slightly more sophisticated version of the auto-tape set-up routine.
There are internal differences, too, which result in the CT-93 having a slightly higher performance in electrical and mechanical (mainly wow and flutter) areas. For example, all internal metalwork on the CT-93 is copper-plated, and extra screening exists around the power supply and critical circuit components and circuit blocks.
As for the listening tests, which stretched over several weeks, let's be clear about the more general points. First, the CT-93 is not just a more complex and expensive deck than the CT900S, it is actually a better one, providing real, definable musical benefits. In broad terms, I would place the £500 CT-900S on a par with Harman's £600 TD4600, though there are important specific differences. The £800 CT-93 is, in my view, a much superior product.
Point two: turning to the flagship model, it is clear from the outset that the CT-93 was never intended simply as a showcase for Dolby S. The fact that Dolby HX Pro can be switched off tends to confirm that the deck was also designed to appeal to the audiophile for whom unnecessary electronic processing is an anathema.
This brings us naturally to point three, which is that the CT-93 worked best used with the absolute minimum of audio processing. There was no question or doubt about this. If all noise reduction, Dolby HX Pro and the display panel were turned off, the deck was capable of some remarkably articulate and lively recordings on metal tapes (TDK MA-XG was used for this test) from a wide range of source material.
The deterioration when any of these things was turned on was subtle (especially in the case of the display illumination), but not so subtle as to be not worth having. There was a consistency about these purist recordings: tape hiss was sometimes audible, of course, but at a low level if recording levels were allowed to peak a few dBs over 0VU on the meters. It was possible to make even quieter recordings with better type II ('chrome') tapes, like TDK SA-X, with very little sacrifice to the precision and focus that is an important component of recording on metal tapes. There was less need to push recording levels, which generally led to a more even-tempered sound with less high frequency 'squash.' This worked a treat with open textured music like the Mozart Sinfonia Concertante.
Predictably, switching Dolby noise reduction in had the effect of dampening the sound down, with a concomitant loss of presence at low levels, Dolby C being a little more culpable than Dolby B. Against expectations based on previous experience however, Dolby S was a useful improvement on both Dolby B and Dolby C. It provided a cleaning up of middle frequency textures, along with a tauter, more agile bass and a generally less dissipated quality at the frequency extremes. There was still a suggestion of low level muddling that detracted from some critical material, but there were some equally clear gains, such as the wordless singing in the Villa Lobos piece Bachiana Brasileira which sounded purer and cleaner even without noise reduction.
The CT-900 demonstrated many of the CT-93's trademarks, including an overall sense of stability that included an absence of even the remotest suggestion of wow and flutter. Nevertheless it wasn't in the same class as the CT-93. It was consistently more muddled and compressed than its senior brother, and it lacked a notable quality of the CT-93 - its ability (as in the Beethoven String Quartet recording) to paint a large-scale soundstage yet still sustain specific placement of individual instruments. By any normal standards the CT-900 ranks as a fine cassette deck. What it doesn't have is the star quality that is the CT-93's special property.
