ShengYa CS-6 fully balanced tube preamplifier & PSM-600 monoblocks

ShengYa products are distributed by Grant Fidelity, located in Alberta, Canada. They span a variety of models and manufacturers, but their focus is high-value audio products. I met the proprietor, Ian Grant, at the 2009 RMAF. He was quite the knowledgeable audiophile, and had a roomful of great products. The CS-6 and PSM-600s that I had in my home system for three months were there, stacked godzilla-like in the manner shown in the lead picture to this article.

I won’t dwell on it, particularly since some might say that my aesthetic judgment is questionable, but aside from looking big and powerful, the CS-6/PSM-600 appearance is quite attractive. All three pieces have a consistent design theme that employs four cylindrical silver/chrome stands that act as feet and run to the top of each unit. The four stands support an all-black body with silver buttons and silver/black dials on the preamp and silver buttons and a big backlit bias meter on the monoblocks.

The CS-6 (MSRP $4,900) is a tubed preamp with a completely dual-channel design down to separate transformers. Four Russian gold-pin 6922 vacuum tubes on gold coated sockets are used for each channel. The preamp has six pairs of inputs (one balanced) and four pairs of outputs (two balanced). As mentioned above, its looks matches the looks of the PSM-600 monoblocks, and it is designed, should the user so choose, to be stackable on top of the monoblocks (as illustrated in the picture above).

The Grant Fidelity website notes that the CS-6 can easily match with just about any power amplifier on the market. Among the features of the CS-6 is the ability to adjust the gain setting to better match the amp it is paired with. I’ve had significant problems in matching solid-state amps with tubed preamps in the past and wanted to see how the CS-6 would do in head-to-head comparisons with other similarly priced tubed preamps. I didn’t have any tube preamp review samples available, so I ended up borrowing two tube preamps from some buddies. One preamp was in the $3,000 retail range, while the other was in the $4,500 range. One was run with both the PSM-600s and my Electrocompaniet Nemo monoblocks, the other was run with the PSM-600s and two Plinius SA Reference stereo amplifiers (configured as monoblocks). The relative gain on the other tube preamps did not match well with any of the high-powered amps, even very low volume settings produced loud volumes. On the other hand, the CS-6 did not have this problem, even without using its gain-adjustment feature. Admittedly this was not intended to be a very scientific test, but the point is that the CS-6 mated very well with several other manufacturers’ high-power amps.

Another thing that jumped out early about the CS-6 was its very quiet performance. My prior tube preamps had always generated more noise than my solid-state preamps. In fact, both of the two borrowed tube preamps I mentioned above exhibited this characteristic, but the CS-6 was quieter considerably. Even in direct head-to-head comparisons with my MBL 6010D and the Pass Labs XP-20, both of which are among the quietest preamps I’ve ever encountered, there was little difference in the background noise generated by the tubed CS-6.

Turning to sonic attributes, the CS-6 also performed significantly better than the two tube preamps in the both the soundstaging and neutrality departments. The CS-6’s obvious superiority to the other two preamps persuaded me that I should compare the CS-6 to the more expensive Pass Labs XP-20 and MBL 6010D, despite the large disparity in price ($8,600 for the Pass and $24,000 for the MBL). These comparisons revealed the CS-6 to be a great value, especially when matched with its companion, the PSM-600’s.

I first compared the CS-6 to the Pass Labs XP-20, which I reviewed in the July 2009 edition of Dagogo. The CS-6 did not have the Pass Labs XP-20’s width of soundstage, but its depth was just as good, if not better, producing a holographic image of the performers. It was both fuller and looser on bass reproduction, but not in an incorrect or unpleasing way – it was merely being more tube-like, which is exactly what you would want and expect from a tube preamp. Its strength, of course, was the roundness, fullness and decay of the musical notes. Top notch solid-state and tube products have steadily addressed their respective weaknesses with advances in design, but if you’re experienced you can generally still hear the difference between the two designs by simple listening.