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The SA7001KI is the first Super Audio CD player to be fine-tuned by Ken Ishiwata and, while embracing all the features above, sees significant improvements over the standard SA7001 model. The KI version features complete copper-plating of the chassis and rear panel to reduce signal-degrading electromagnetic radiation. The power supply replaces the standard EL transformer seen in the basic version with high grade toroidal transformer. This transformer has a much higher efficiency due to the very low impedance of the windings with higher current capability.

When you consider the Marantz CD-6000 KI sold for £500.00 back in 1995, the SA-7001 KI price at £600.00 is an absolute bargain. The SA-7001 has already won the EISA 2006/7 award and the SA-7001 KI has been reviewed in the November 2006 issue of Hi-Fi World magazine and received the prestigious 5 globes.

Hot Rodding the 7001.

The SA-7001 electronics are a virtual clone of the now discontinued SA-8400 which cost £700.00. On the base of this alone this makes the SA-7001 remarkable value at £430.00. Having previously modified the SA-8400 with great success we at Audiocom were confident that the results from SA-7001 and SA-7001 KI would be equally effective. This was particularly true of the ‘KI’ version where master clock, voltage regulation and digital circuitry does not form part of the KI tweaks.

The master clock oscillator in the SA-7001 is located on the DSP board underneath the CD transport. The oscillator design uses a crystal connected across a single gate CMOS inverter. The oscillator works by making the crystal unit filter the output signal of the CMOS gate, and sending it back to the input at a phase shifted sine wave of some 100 mV amplitude. This signal is then buffered by a further single gate CMOS inverter before being divided via two line terminating resistors at the output.

The first level of modifications, Level-1 for the SA-7001 KI is based on significantly improving the master clock. To accomplish this we completely removed the CMOS oscillator and buffer and fitted an ultra-low jitter clock, the Audiocom Superclock 4-S using a short coaxial cable with line termination. The results were exhilarating and highly rewarding for CD & SACD playback. The sonic performance of both digital formats increased markedly placing a clear and substantial gap between the stock SA-7001 KI and the re-clocked player using Superclock 4. The prominent effects of this upgrade are the increase in sound-stage depth and width where the increase in acoustic space gives music greater perspective and freeness. The levels of resolution improve substantially allowing more insight into recordings with a level of naturalness, truth of pitch and timbre absent from the stock OEM player.

Now the 7001’s jitter blues are a thing of the past we turn our attention to the main power supplies. The KI version of this player uses Schottky diodes and high grade Elna “For Audio” for the main power supply. The on paper performance of Schottky diodes leans towards this type of diode being the optimum choice for everything audio; they provide near instantaneous switching with no reverse recovery transients; but the music sounds slightly bleached and lacks the musicality of other “fast” diodes. For the Level-1 modification we replace the Schottky diodes with HexFRED diodes; these are ultra-fast diodes with soft recovery which in sheer sonic terms outperform the Schottky variety. To complete these set of modification the general purpose power supply reservoir capacitors for the digital power supply are upgraded to Panasonic FC type, the FC capacitors while not labelled “audio grade” outperform many alternatives, including several audio types providing a well focused mid-band, firmer bass, with a more open and airy high frequencies.

Level-2 builds on the performance of level-1 by improving the regulated power supplies for the DAC, and improving the quality of signal on the analogue line-outs. The DAC used in the 7001, the CS4397 requires both a 3.3V digital supply and a +5V analogue supply and for this Marantz have selected BA033T & BA05T fixed, 3-pin regulators. Each of these has a typical Ripple Rejection Ratio of 55 db (f = 120Hz, load = 100 Ma), and noise is in the region of 45µV. The impact of this noise riding on the DC rails affects clock lines, digital filter and the digital to analogue conversion process of the DAC chip. The sonic result of this is unwanted glare, edginess and compression to the sound. These generic regulators for the DAC are replaced with the Super-regulator 3, a discrete, ultra-low noise regulator which delivers clean, fast power to the DAC.

The Bybee Slipstream purifiers are added to the L/R signal outputs at the RCA jacks. The audible improvement with this upgrade is quite remarkable, a layer of grain is removed from the sound, and you can hear much deeper into recordings. There is a marked improvement in the soundstage, the music is more open, expansive and focused. 

Marantz SA-7001KI Level-1 Upgrade

4x IR HexFRED diode for analogue power supply.
4x IR HexFRED diode for digital power supply
Superclock 4 master clock
5x Panasonic FC capacitors for digital power supply.
5x Rubycon ZA regulation bypass capacitors.
Sontech SFRT-AL resonance control.

Marantz SA-7001KI Level-2 Upgrade

4x IR HexFRED diode for analogue power supply
4x IR HexFRED diode for digital power supply
Superclock 4 master clock
5x Panasonic FC capacitors for digital power supply.
5x Rubycon ZA regulation bypass capacitors.
1x Super-regulator 3 for DAC +5V supply.
1x Super-regulator 3 for DAC +3.3V supply.
Sontech SFRT-AL resonance control.
Bybee Slipstream purifiers for RCA signal output.