Junk mail rarely serves a purpose, but I'm pleased that I opened one of those 'You Can Win #100,000!!' envelopes from a famous producer of junk mail. In it, the company showed a breakdown of what you could do with your winnings, eg buy a car, pay off your mortgage and so on, but what intrigued me is that one of the items listed was 'Top Quality Hi-Fi......#3500'. This caused my heart to swell because it meant that a totally 'non-enthusiast' source has publicized the notion that hi-fi can be justified at above-Amstrad prices. It means that I don't have to apologise for the Counterpoint SA-12, at a measly #1250, because it could conceivably fit into that winner's system.
I'd like to think that British audiophiles on a budget have matured enough to accept that exotica costs big bucks in the way that car enthusiasts of limited means can understand the price of a Ferrari. And the only way you can appreciate the Counterpoint SA-12 is by looking at it relative to the high end, not by comparing it to NADs or Creeks.
Although this amplifier has been around for a few years, Counterpoint has continued to refine it in the way that Quad continually refines its products: without making a big deal out of it. So although there's no Mk II suffix, this beast is supposed to offer better performance and greater reliability than the early samples.
I don't have an early SA-12 to hand, but I've heard this amp enough times to know that it's a perfect gap-filler between the sub-#1000 and #2000-plus amps. Its competition includes a slew of British amplifiers as well as imports like the Aragons, so it's not No 1 in a field of 1. But it does have some distinguishing characteristics which could create its own niche (see the Gryphon review in this issue for further thoughts on niche marketing).
For one thing, the SA-12 is a valve/solid-state hybrid, which means that those who vacillate between the two technologies can satisfy both levels of their schizophrenia. The SA-12 employs four 100W MOSFETS per channel in the power stages, while all voltage amplification and output stage drivers are valve circuits (two ECC88s/6DJ8s per channel). The advantages are both musical and practical, because the valves offer their sonic merits where they matter most, while the MOSFETS -- easily driven by the valves -- can almost emulate the classic tube sound while delivering greater current than an all-valve design could muster.
This latter aspect is important, and not just because fashion has dictated that current capability is THE yardstick for assessing modern amplifiers. Exotic speaker designs, the continuing
popularity of small speakers with low sensitivity and low impedances -- these have created a real, as opposed to imagined demand for high-current-capability amplifiers. Counterpoint has
employed two N-channel and two P-channel MOSFETs in a complementary-symmetry Class-AB configuration. To broaden the amplifier's Class-A range, which eliminates switching distortion, a high bias is required; this explains the need for fairly large heat sinks and other 'warm zones' not caused by the ECC88s.
The MOSFETs are driven by a cathode follower consisting of a single ECC88 per channel connected in parallel, the output of the drive stage being capacitively coupled. Voltage amplification is derived from two cascaded common cathode amplifiers, using half of an ECC88 triode for each stage. Local feedback is used to improve linearity, while global feedback is returned to the cathode resistor of the first stage from the cathode follower
driver stage. Biasing for the first stage is a mixture of fixed and cathode biasing. The SA-12's output stages are kept out of any kind of feedback loop because the company feels that it
sounds much better; this necessitated the use of MOSFETs normally found in switching power supplies for their lower output impedance when compared to the MOSFETs typically found in audio equipment. The SA-12 sports three, non-regulated power supplies.
The SA-12 is compact by prevailing high end standards, measuring only 480x113x322mm (WHD). Counterpoint has a knack for producing hardware which looks both utilitarian and elegant at the same time, all very Californian, so the SA-12's styling should please both the aesthete and the technoid. It can be rack-mounted in a standard 19in frame, but do allow for ventilation.
External details are few. The front panel features only an on/off switch and a two-colour LED to indicate warm-up (red) and full operational status (green). The SA-12 takes around two minutes to stabilize and some of you might get a bit frustrated waiting for the red to turn to green, but life's too short to get worked up about it, and such a mood means that you're too tense to enjoy music. If this is the case, just leave it on 24 hours a day; it'll sound better anyway, because optimum performance isn't delivered for at least an hour or three.
At the back, the SA-12 features a pair of gold-plated phono sockets for signal input and five-way, 19mm spaced binding posts for speaker connections. The sides are filled with sharp-cornered heat sinks. Overall fit and finish is very good, but a long way from Rowland/Krell standards.Read more about the SA-12 on Page 2.