These are some Sid examples which i have recorded from a Commodore 64 with the SwinSID installed. You can Download the original Sid track in .sid file format and the SwinSID in .ogg file format (High Quality), so you can compare the musics.

• Natural Wonders 2 by Alexander Rotzsch (Fanta) 2008 Oxyron – SID (8580)
  
• Natural Wonders 2 by Alexander Rotzsch (Fanta) 2008 Oxyron – SWINSID

• The Alibi by Thomas E. Petersen (Laxity) 1989 Maniacs of Noise- SID (6581)
• The Alibi by Thomas E. Petersen (Laxity) 1989 Maniacs of Noise- SWINSID
  

• My Little Pony by Alexander Rotzch (Fanta) 2005 Chorus – SID (8580)
• My Little Pony by Alexander Rotzch (Fanta) 2005 Chorus – SWINSID

• Albino Human by Alexander Rotzsch (Fanta) 2006 Fanta – SID (8580)
• Albino Human by Alexander Rotzsch (Fanta) 2006 Fanta – SWINSID

Some Sid tracks play perfectly others need some emulation fixes.

SD2IEC is a hardware mass storage device using an SD/MMC card and interfacing with the IEC bus. It is based on the ATmega644 or ATmega1284p microcontroller from the Atmel AVR microcontroller family.

The most prominent use of SD2IEC is emulation/replacement of a Commodore-1541 disk drive for a C64. Hardware and the microcontroller’s firmware is available as open source (GPL).

Changelog:

2010-11-07 – release 0.10.0

• Deprecation notice: E-R and E-W commands will be removed in the next release.
• Improved reliability of Nippon loader.

source: sd2iec.de gitweb forum thread c64-wiki