The high resolution PCM at 96-192KHz 24bit offer the possibility to have a good quality digital signal near to the analog.
The DSD is very different from PCM, using a sampling frequency 64 times higher than that of a standard Compact Disc, offers a frequency response of up to 100 kHz and a dynamic range of up to 120 dB across the entire audible range.
The DSD tracks on paper should be better than 192KHz 24bit because the two conversions (from and to the analog) are more simple but the test by Erik-Thienhaus Institute in Detmold, Germany, seems to contradict this.
I have found a good explanation of the DSD on Korg web site, see here.
The Super Audio CD can store DSD informations but in some case SACD are recorded using a DSD derived from an original high resolution PCM so in these case the benefit of DSD is  lost.
Also with a PC it is not easy play Super Audio CD and DSD files becasue there are only few very expensive modules with DSD output .
The easier method to ear this technology is buy a true SACD player and use only pure DSD tracks like the Fone.
I have spoken with Giulio Cesari Ricci about the Super Audio CD produced by the Fone and he told me that all the titles in the range 001 - 019 are originated from Analog Master and the more recent Super Audio CD are directly recorder in DSD mode. 
To record in the PCM format there are many audio interface line the EMU0404 USB but to record DSD there are few dedicated systems.
The cheaper method to record in DSD mode is use the new Korg MR-1, MR-2, MR-1000 or MR-2000.

The MR-1000 since to be the best of these models because it is mobile and with a good capacity to store Hi-resolutions tracks.
This component is not expensive, only about 700-800 euro, but it cannot be used as media store because the internal hard disk (1.8") is limited to 40Gb (7-14 hours of DSD).
Only record companies can create Super Audio CD with a recorded DSD track so we cannot create SACD in the house.
It is possible create DSD Disc but only the Sony SCD-XA5400ES and new SCD-XE800 can play these.

There is a SACD modules for OEM produced by Daisy called GyrFalcon 6 using the SD6.3 SACD module but it does not support the direct DSD mode and the signal is converted in PCM.

 

So I started to analyze many commercial SACD player to find a good product to upgrade with some modifications to increase the sound quality.
Before buy a SACD player we must be sure that it is a pure DSD player because some  SACD player use the Daisy SD6.3 SACD module.
In the following SACD players I have analyzed the schematic and I have verified that the DAC chip receive both PCM and DSD signals.
We must exclude also all the multi format DVD/SACD because these use a switching power supply and in many case the signal is converted to PCM.

Frontal photo	Brand	Model (click to download schematic)	Out	DAC chip	Opamp	Price
	Sony	SCD-XE597	6 ch	TI / Burr-Brown DSD1751 Vout	NJM4565M single power supply	150-200 euro
	Sony	SCD-XE800	2 ch	TI / Burr-Brown DSD1751 Vout	NJM4565M single power supply	200 euro
	Sony	SCD-XA5400ES	2 ch + HDMA	TI / Burr-Brown 2 x PCM1796 Iout	OPA2132	900-1000 euro
	Sony	SCD-XB940	2 ch	Sony Iout		used 200-250 euro
	Pioneer	PD-D6-J	2 ch	TI / Burr-Brown 2 x PCM1738 Iout	NJM5532	400-500 euro
	Pioneer	PD-D9-J	2 ch	Wolfson 2 x WM8741 Vout	OPA2134	800-900 euro
	Marantz	SA8003	2 ch	Cirrus CS4398 Vout	HDAM (CD17 model)	800-900 euro
	Marantz	SA8400	2ch	Cirrus CS4397 Vout	HDAM (CD17 model)
	Marantz	SA11S1	2ch	NPC SM5866 Iout	HDAM (CD17 model)	3000 euro
	Denon	DVD-2930CI	6ch + HDMI VIDEO	TI / Burr-Brown 2 x PCM1791 Vout	NJM2068	700 euro

Only 3 of these models use the best DAC the Marantz SA8003/SA8400 with last Cirrus, the Pioneer with WM8741 and Sony with PCM1796.

I never have tested the SM5866 or others NPC DAC chips.

In my DAC Final article about DAC comparison the best chip was the Analog Device AD1955 and the Wolfson WM8741

The Wolfson is used in the Pioneer PD-D9-J now available in the new version PD-D9MK2-K.

About the analog output stage all the op-amp are terrible for the sound so it will be changed.

The DVD-2930CI is a multi-standard video DVD but it can decode SACD as pure DSD signal.

As told before only the Sony SCD-XA5400ES and the new SCD-XE800 can read also DSD disc so it is possible use it to play DSD files recorded by the Korg MR-1000 following this guide (mirror).

The SCD-XB940 is an old model but with simple modifications can give good results (see diyaudio forum) also if cannot read CD-RW and the DSD Disc.