Analog Stages + Mic Pres
We’re able to completely rework the entire analog stage, including the mic preamps, line inputs, voltage reference circuitry, and headphone amp. We’re fans of Burr Brown’s OPA4134, and we substitute those for the TL074 opamps used in the mic preamp and line inputs. We’re able to reduce analog stage noise created by the 002’s phantom power circuitry as well as reducing the RF noise created by the 002’s switching power supply.
The Clock
While experimenting with clock designs, we found that we liked the quality of the audio better when the master clock frequency was increased. Due to the superior nature of third overtone XO crystal oscillators (they have inherently less jitter than fundamental XO oscillators), we decided to increase the 002’s original master clock frequencies, and then divide them by two to obtain the needed frequencies. We started with a pair of ultra-low jitter (1 picosecond average) XO oscillators, one for 44.1 kHz and its multiples, and one for 48 kHz and its multiples. We use a proprietary method that keeps accumulated jitter and switching noise to a bare minimum: under 10 picoseconds. Coupled with our approach to converter configuration, we’re able to bring the 002 to a level of performance that rivals or exceeds digital systems that cost thousands more.
Taking the 002 even further
Over the last few years, we’ve experimented with several different design approaches for digital audio, starting with the power supply and moving into advanced theories of clock and data harmonic structure. We came up with several unique approaches to the 002 and 003 modifications. These are practices that aren’t used by any other manufacturer. We’ve found them to yield sonic improvements that rival the most expensive conversion systems available in pro audio today.
We began using a low-emission toroid to power the analog and digital stages separately because it improves overall sonic character. It also completely eliminates the power supply as a source of crosstalk between the analog and digital circuitry. This is available on both the Tweak Head and Signature Series modifications.
Converters are very sensitive to their power sources, and proper configuration is very crucial. Although there is an approach commonly used by all manufacturers, we began experimenting with new design theories. We approached it from the perspective of minimizing resonant frequencies and current noise within the power supply, and the resulting overall impact on the conversion process. After almost six months of testing, we came up with a proprietary method for configuration of the 002’s converters. We feel the end result represents a great breakthrough, and takes the 002 to a completely new level of sonic quality. This is included on every 002 and 003 modification we perform.
Our latest effort has focused on the overall harmonic structure of the master clock, and the overall sonic effects yielded during the conversion process. These experiments have yielded our 220/270SP Master Clock; a master clock system that we feel is among the best in the industry. This is available only on the Signature Series 002 and 003.
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