zapco Reference 1000.4, User Manual

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4
ZAPCO
The Reference Series
The Reference series (originally called AG) marked ZAPCO’s first
effort to bring the high quality that built the ZAPCO legend to an amplifier
line that everyone can afford. The response has exceeded the company’s
wildest expectations. Why has the line been received so well? We think the
answer is simple. The Reference Series amplifiers sound as good as, or
better than, other brands best amplifiers. This is possible because we took a
very different approach in the design of our Reference Series.
Rather than follow the crowd and build a less expensive amplifier
around cheaper components, ZAPCO chose to develop a more efficient way
to build the best, high voltage, amp on the market. The Reference Series
was modeled after the Studio Series including the same circuit design, Op-
Amps, Gate Drive Boost circuit, 1%, metal film resistors and high current, Bi-
Polar outputs devices. One major improvement was the addition of
SymbiLink™ balanced line inputs.
Did we make any sacrifices to achieve this new Series? Certainly,
and these fall in two areas. First, we gave up a certain amount of headroom.
In the Studio Series, every model was overbuilt by 100%. The Studio
amplifiers had twice as many output devices as it needed to run full power
on all day long. The Reference Series amplifiers have only 1½ times the
outputs devices required. We still overbuild the Reference Series by 50%,
just not as much as the Studio. This is a difference that will almost never be
heard. The other sacrifice we made was in size. The Studio 500, for
example was probably the world’s smallest, 900-watt (only 19”L x 5.75W),
class A/B, amplifier. The Reference 1100.1 is 23”L x 7.5”W, which is more in
line with what people might expect from that much power. While the smaller
size can be more convenient, it took much more time to build.
So! We gave up a little headroom and we had to deal with a larger
footprint. In return, we got a very neat design with an inordinate amount of
extremely clean power at a price that made it an incredible value. While the
great price and clean power made the Reference an obvious choice, we
were not content to just make a more affordable series.
The Reference amplifiers received all of the features that we felt
were missing from the older Studio design. Every Reference amplifier has a
fully variable electronic crossover that can be switched to high pass or low
pass, and an input switch for stereo, summed mono, or bridged use. Every
Reference amplifier has an adjustable bass EQ control. And, perhaps most
significant difference is the addition of SymbiLink™ Balanced Line inputs for
a lower noise floor, better dynamic range, and less signal loss on long runs.