Ultraclock mk2 is a state-of-the-art master clock for CD/DVD/Blu-ray players, as well as D-A Converters, USB computer interface, external reclocker.

The Ultraclock mk2 sets a benchmark for sound quality and provides unmatched measured performance.

I recently had the Off-Ramp upgraded to the UltraClock ($800) from the standard SuperClock.  - With the UltraClock, shit man, this thing is stellar. Worth the $800? I find that the UltraClock is equal to any cable or AC cord upgrade—which can, in the right place and right measure, transform a system. Yeah, that is the UltraClock.- Dave Clark, Postive Feedback October 2009.

Description

• Voltage Reference

An important factor when designing a high performance clock is voltage reference noise. Low frequency jitter is the worst and most audible of all and the noise floor should remain ultra-low down even to well under Sub One Hertz. The problem is that noise of voltage references below 10 Hz rises steeply, the band of noise which we need to be lowest of all.

We studied a group of voltage references to find the lowest 0.1 – 10 Hz noise, the MAX6126 was found to have ultra-low noise at low frequencies (1.3µV @ 0.1 – 10 Hz), and ultra-low wideband noise (60nV). A further advantage of the MAX6126 is that it has a noise reduction pin and with a 0.1µF capacitor wideband noise is reduced from 60nV to 35nV.

For Ultraclock mk2 our goal was to further reduce low frequency noise, so we employed an innovative circuit consisting of 32 precision parts which stacks 4x MAX6126 @ 2.048V references. This reduces low frequency noise to 650nV @ 0.1 – 10 Hz, and wideband noise to 18nV.

This solution is far superior to using a single, low cost LM329 as used in other reference clocks; the low frequency voltage reference noise of 4x MAX6126 is 40 times quieter with 650nV @ 1 Hz compared to 25µV @ 1 Hz for LM329.

• Oscillator

The Ultraclock’s ultra-low phase noise oscillator uses a discrete high-performance oscillator topology which places the high Q quartz crystal at the lowest impedance and lowest noise point of the circuit. The unique circuit uses a pair of ultra-low noise, wideband transistors to produce a pure analogue sine-wave with lowest phase. The pure sine is translated to a square wave while maintaining lowest jitter across a wide bandwidth. The RF stages are then dual screened to eliminate unwanted RFI/EMI noise.

• Printed Circuit Board

The layout and quality of the Printed Circuit Board (PCB) is critical to the performance of a clock oscillator where we are dealing with RF signals. Ultraclock uses a 4-layer, Gold plated PCB, which enables power and signal paths to be significantly reduced and improved ground layer compared to the conventional 2-layer PCB.

• RF/EMI Screening

To eliminate RF/EMI noise from the clock and power supplies circuits, each circuit sector is dual screened. Both the voltage reference module and RF stages features an RF/EMI screen in the PCB layer and a custom RF screening can. The RF screen covers the oscillator through to sine-to-square conversion stage to the SMB output jack. This provides 100% RF/EMI screening so noise from your CD/DVD player cannot affect the clock performance and vice versa.

• Sound Quality

With the Ultraclock mk2 system you are no longer at the mercy of CD’s truncated version of musical reality. The sound is so much more ‘analogue’ that you are detached from the fact that you are actually playing compact disc. Every inner detail and nuance is presented, shift in tempo felt, emotive clues, the music has a charismatic quality considered absent with CD; the music is enthralling.

Technical Specifications:-

■ Input Voltage range: +9V – 18 V DC
■ Temp co. +/- 1ppm accuracy.

■ Ultra-low jitter. < 0.5 ps RMS

■ Switchable Output 3.3V or 5.0V p-p.
■ Dimensions. L = 82mm x W = 45mm.