| Black Lion Audio Dig 003 Tweak Head Modification Details
Digi 003R 'Tweak Head package named after the audio import setting in Pro Tools, this package offers clock, analog, converter decoupling, and a separate linear power supply for the analog stages that increases headroom by 12dB!
The 003 is, of course, the successor to the 002. We frequently get asked if the 003 is better than the 002, and while it does offer some improvements, we feel it's also inferior in certain respects. According to an email we received from Digidesign's engineering department, Digi has utilized the HD system's internal clock in the 003, and improved the power supply as well. The 003 also appears to be compliant with the European Union's new lead-free directives for electronic equipment, whereas the 002 is not. Conversion is handled by Cirrus Logic, which is a change from the AKM-based conversion found in the 002. The A/D uses the CS5361, a 115dB D/R A/D which is pin-compatible with Cirrus Logic's flagship CS5381 A/D. We consider this an improvement over the 002 because it offers higher dynamic range than the 002's A/D. The D/A is handled by the CS4392, which we felt was inferior to the 002's D/A. The 003's analog stage headroom is increased over the 002 by 15dB due largely to higher analog stage power supply voltage. For the 003's analog section, Digi uses Texas Instruments NE5532, which is a change from the analog stages found in the 002.
Analog Stages + Mic Pres
Like its older brother, there are a world of improvements to be had within the analog stages. We wanted to improve bandwidth and transient response in the 003, so we utilized a quieter, faster opamp for the mic preamps, line inputs, and line outputs. The result is a smoother, more detailed audio response with a much more open top end.
The Clock
While experimenting with internal 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 because they have higher 'Q'), we decided to utilize the same clock that we use in the 002. We increase the original master clock frequencies, and then divide them down as necessary. We started with a pair of ultra-low jitter (1 picosecond delta sigma average) XO oscillators, one for 44.1 kHz and its multiples, and one for 48 kHz and its multiples. We divide these two frequencies using a proprietary method that keeps accumulated jitter to a bare minimum: under 10 picoseconds. Would you ever use the word "punch" when describing the sound of your 003? With our internal clock, you most certainly will.
Taking the 003 even further
In late 2006, we began experimenting with linear power supplies in the 002. We've never been big fans of switch mode supplies in audio, mostly because of the way they seem to strip the audio of any real body or impact. By powering the analog and digital stages separately, we felt we could improve overall sonic character as well as completely eliminating the power supply as a source of crosstalk between analog and digital. By using a low-emission toroid with a bigger power supply rail, we are increasing headroom by 12dB over the stock design, and as a result, improving sonic impact.
We also toyed with different converter configurations. Converters are very sensitive to their power sources, and proper decoupling is very crucial. We began to experiment with some theories concerning resonant frequencies within power supplies and their overall impact on conversion. After almost six months of testing, we came up with a proprietary method for reducing the noise and decoupling the 002's converters. We feel the end result represents a great breakthrough. We're also able to offer these same modifications for the Digidesign 003. |
