Unearthing SCD-1 Sound

Where the SCD-1 primarily falls down on performance is its master clock system, regulated power supplies and post DAC analogue processing stages. In the 1999 Stereophile review measured jitter was a reported 146.8ps peak-peak. While this was quoted amongst the lowest measured by stereophile it can be substantially improved upon by upgrading the OEM clock and adding a dedicated clock power supply. This ensures that not only the data related jitter is reduced by the extremely low phase noise clock but power supply jitter is dramatically reduced. To achieve this we have two solutions, the first is the highly acclaimed Superclock 4 ultra-low jitter clock accompanied by the Superclock 4 power supply. For the higher levels of upgrade we use the state-of-the art Ultraclock system, the Ultraclock has unsurpassed performance in its measured and audio performance setting the standard for others to follow.

The SCD-1’s DC regulated power supplies are supplied by 78xx & 79xx generic regulators. The output noise of the 7805 is typically 40µV, with a ripple rejection (AC noise) of 80db at low frequencies which worsens considerably as frequency increases. This noise riding on the DC rails arrives at the power input pins of every digital & analogue processing stage; noise on the input of the DAC = noise/errors on the output. The 78xx & 79xx types are used throughout the SCD-1 in the main power supply and audio board. Our upgrades We upgrade the generic regulation with ultra-low noise, wide bandwidth discrete regulator boards. These regulators feature (1) very wide bandwidth (2) ultra-low noise (3) high PSRR. The new regulators design means noise is rejected at the input so the circuit being powered is "isolated" from input noise. Compared to the best standard regulator which at best offers 80db rejection, the new regulators provide a PSRR of 130db across a wide bandwidth.

Passive component quality in the SCD-1/777ES is very good, Elna Silmic capacitors, Riken resistors, are used throughout the audio board with a mix of good quality op-amps in the analogue output stage. Although component quality is of a high standard there are several key areas which are not optimised and our upgrades replace specific parts and optimise values for the circuitry. These high grade parts include Sanyo OS-CON capacitors for locally de-coupling the digital filter, S-TACT (A Synchronous Time Accuracy Controller) and Current Pulse DAC’s, Sanyo OS-CON SP regulator bypass capacitors, digital de-coupling capacitors.

The post DAC analogue processing stages in the SCD-1 are active op-amp based, and the OEM selection of op-amps are a limiting factor. For example, the OPA2604 op-amps used for current-to-voltage conversion (I/V) can be substantially improved upon by replacement with a modern, ultra-low noise, ultra-low distortion audio op-amp. For the current-to-voltage stage we upgrade the 2604 with the new LME49720 from National Semiconductor.  The LME49720 is an op-amp to love, if reading spec sheets gets you going then check the excellent 120db PSRR or the vanishing low 0.00003% THD, the 49720 is the closest to no op-amp we have heard in a long time. Further the analogue stage we meet the AD712 used for low-pass filter, the AD712 is classic workhorse for audio circuits and used by Sony since the late 1980’s. By modern standards it is still a good performer but can be improved upon and for this stage we have selected the AD825 op-amp, one pair per channel are required on Brown Dog  adapters. With the AD825 Detail becomes optimal at both low and high levels, dynamics are powerful and controlled, the music gains a warmer, more natural sound.

Another new introduction in the Sony modifications is the used of the Bybee Quantum Purifiers. Bybee Quantum Purifiers operate on the quantum mechanical level to regulate the flow of electrons that make up the signal. Current flow within the Quantum Purifier is unimpeded and ideal. During transit through the Quantum Purifier, quantum noise energy is stripped off the electrons, streamlining their flow through ensuing conductors. Unwanted quantum noise energy dissipates as heat within the Quantum Purifier rather than emerging as a layer of contamination residue over the audio/video information.

Audiocom have 3 levels of upgrades available for the SCD-1 & SCD-777ES, the entry level-1 moves the CD & SACD performance on considerably over the stock unit whereas the higher levels give a true testimony of the sound quality available from this flagship Sony SACD player.

Sony SCD-1/777ES Level-1 Upgrades

• 1x Superclock 4 ultra-low jitter master clock.
• 1x Super-regulator 3 for +5.0V analogue regulated power supply.
• 2x Gold plated, Beryllium Copper 8-pin sockets for current-to-voltage converter op-amps.
• 2x LME49720 op-amps to replace OPA2604 for current-to-voltage converter stage.
• 6x Sanyo OS-CON SP capacitors for regulator bypassing.
• 2x Bybee Large Quantum Purifiers for AC power supply input.

Sony SCD-1/777ES Level-2 Upgrades.

• 1x Superclock 4 ultra-low jitter master clock.
• 1x Super-regulator 3 for +5.0V analogue regulated power supply.
• 2x Gold plated, Beryllium Copper 8-pin sockets for current-to-voltage converter op-amps.
• 2x LME49720 op-amps to replace OPA2604 for current-to-voltage converter stage.
• 6x Sanyo OS-CON SP capacitors for regulator bypassing.
• 1x Superclock 4 ultra-low noise clock PSU.
• 2x Super-regulator 3 for +7V DAC power supplies.
• 2x Super-regulator 3 for -7V DAC power supplies.
• 2x Sanyo OS-CON SP for DAC reference.
• 1x Sanyo OS-CON SP for +5V digital bypass.
• 2x Bybee Large Quantum Purifiers for AC power supply input.

 Sony SCD-1/777ES Level-3 Upgrades.

• 1x Ultraclock reference master clock oscillator.
• 1x Ultraclock reference clock power supply.
• 1x Super-regulator 3 for +5.0V analogue regulated power supply.
• 2x Gold plated, Beryllium Copper 8-pin sockets for current-to-voltage converter op-amps.
• 2x LME49720 op-amps to replace OPA2604 for current-to-voltage converter stage.
• 2x AD825 op-amp modules using Brown Dog adapters for low-pass filter.
• 6x Sanyo OS-CON SP capacitors for regulator bypassing.
• 2x Super-regulator 3 for +7V DAC power supplies.
• 2x Super-regulator 3 for -7V DAC power supplies.
• 2x Sanyo OS-CON SP for DAC reference.
• 1x Sanyo OS-CON SP for +5V digital bypass.
• 2x Bybee Large Quantum Purifiers for AC power supply input.
• 2x Bybee Slipstream Quantum Purifiers for +/- analogue supply.