EGMATING, GERMANY (04.07.2015) – Five years after the introduction of the award-wining Reference Amplifier Family, it is time for the next highlight, the Reference PURE Generation. Even before the official launch in July 2015, it’s already clear: These are the best Sound Quality amplifiers Ground Zero has ever built. The two-years development of these High-End amplifiers was focusing three things: Direct signal ways, lowest possible loss and absolute Symmetry.
Direct signal way: On the Reference PURE, all filters and unnecessary controllers, which could influence the signal, have been removed when designing the brand new circuit layout. The result is the most unobstructed and unadulterated signal flow from the RCA input all the way to the speaker terminals. This also clears the space for using the elite class Alps potentiometers, which control the Bias setting from using traditional Class AB up to almost Class A. They are also used to control the input sensitivity, either per channel or per channel pair by pressing the sum switch.
Avoid any possible loss: To further reduce any signal loss and distortions, the Reference PURE is using only the outmost and most sophisticated components. And that starts from the Rhodium RCA connectors up to the Type LM4562 OP Amp, which is definitely among the best what can be used in an High-End amplifier. It´s THD+N is rated lower than 0.00003%. Exclusively developed and produced for Ground Zero, brand new Mundorf M-Caps are applied. Together with the latest “Generation II” ELNA Silmic electrolytic capacitors and custom-made metal oxide resistors, the lowest loss of the signal could be achieved through the amplifier section.
The Sanken transistors are well known from the standard Reference amps, but to improve even more on the thermal stabilization, selective and low-tolerance Vishay Dale emitter resistors have been up-streamed. In addition to all that, bipolar secondary capacitors have been developed in cooperation with Mundorf. As a result of using these unique Mundorf E-Caps, the Reference PURE 4-channel achieves a buffering of 98.000μF; the 2-channel version is rated with 48.000μF.
Absolute Symmetry: On the primary side, the new Reference PURE amps differ significantly from the standard Reference Amps. The power supplies have been not only separated electrically, but also physically. This leads to a symmetrical layout of the circuit, so that the 4-channel version can be considered as a “Dual-2-Channel” Amp. And strictly speaking, the 2-channel Reference PURE is technically a “Dual-Mono” as the right and left channel is virtually absolute separated from each other. Both models are using inboard Mini-ANL fuses; their high performance transformers are designed to extreme loads down to 1Ohm. What´s left to say are the impressive power ratings. The “Reference 2 PURE” is rated with 2x 420/750/1150 Watt (4/2/1Ohm), the “Reference 4 PURE” delivers 4 x 150/270/425 Watt.
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