I'm not sure how to "note" feature, well, I stick by that description I found on an online store:

64 channels polyphony of 32 parts
Complete studio module with 64 channel MIDI synthesizer in 32 games for making movies, karaoke, orchestrations and more.
660 sounds and 23 drum kits GM2/GS/XGlite
Compatibility with standard GM2/GS/XGlite allows a wide variety of musical genres such as pop, contemporary, classic or otherwise using the most realistic sounds including grand piano, Rippin 'Guitars, Jazzy Sax and Ethnic Drums!
Optical Digital Output (S / P DIF)
Optical digital output allows for quality sound output, not found on other models in this price range
USB bus powered, no adapter
The USB connection transmits power and data
Easy computer connection (Serial / USB)
Connects to your computer through the serial port, or more simply through the USB port on any Mac or PC.
Specifications:
- Internal Sounds: 3 goups (Classical, Contemporary, Solo)
- Number of sounds: 660
- Number of Drum Kits: 23
- Effects: Reverb, Chorus
- Power: USB bus or DC 9 V (AC adapter included)
- Dimensions: 203 (W) x 159 (W) x 35 (H) mm
- Weight: 0.4 kg/15 oz
- Accessories: USB cable, user manual, CD-ROM with drivers for the SD-20, AC adapter.
System Requirements:
Windows
Operating system: Windows XP Home or Professional Me/98/2000/XP
Computer: Windows compatible PC Me/98/2000/XP equipped with a USB port as standard
Processor: Pentium 200 MHz or higher
Memory (RAM): 32 MB
USB Controller: Intel USB chipset recommended
Macintosh
OS: MacOS 8.5, 8.6, and 9.x (*)
Computer: Apple Macintosh with USB standard
Processor: PowerPC G3/233 MHz or higher
Memory (RAM): 64 MB
(*) Requires OMS 2.3.7 or higher, or FreeMIDI 1.35 or higher.


UTILIZATION

I used it a few times with a laptop computer, keyboard master and Cubase to create songs midday, it was perfect.

Then he helped me to play midi files to record, via the optical output on a mini disc, it worked well. You can choose 4 types of noon so when the glue sounds used by the creator of the file it sounds good.

Now I use it for the sounds of organ and piano with an old stage piano (Roland RD-150) which has some beautiful sounds (scat), but not those.


SOUNDS

The sounds are interesting in my opinion because even with a small amplification not well adapted (micro cube), there is some clarity and never breath (as opposed to the direct use of the piano scene cited above).

Also, it adapts to all types of sounds (noon midi2, GS and XG), which makes a good interpreter of all types of MIDI files that can be found on the web.

The audio outputs (RCA jack and optical) allow to use it to create audio files from noon.

In addition to my current use of a keyboard, the surprise is that the breath of the output jack of the keyboard is not present at the output of the SD-20, which allows me to use a small amp not really made for (micro cube) and working properly. The sounds are also amazing quality grades and in the extreme bass and treble, where the keyboards are fishing too often.
But this use is very limited because the keyboard, the controller functions limited, can not access all the sounds present in the SD-20. As this small lightweight expander has only two buttons (volume and method to select the type of MIDI), you need a computer to handle it really. (I'll still ask on the forum if anyone has a solution) At the same time it is made for that, for computer music ...

OVERALL OPINION

So this little expander few grams but still solid, is for those who want to work for MIDI with the computer without increase. In addition it feeds with usb or via the transformer, as desired.
Oh, I could not install a PC with 64 bit but it's done, everything only the windows driver, do not try to install the old CD. With Band In A Box that turns nickel.