I just stumbled onto this site the other day. PS3SACD.com is a guide to the models of PS3 that support SACD playback, their availability, catalog, and mods to improve the audio quality.
Interestingly, none of the mods are circuit based. They all have to do mechanical modifications, which will affect the resonance modes of the disc. This improves laser tracking, but what if skipping isn’t an issue? What sort of improvements will you hear? I raised this question a while back, while discussing BluSpec discs. It’s looking like I’ll need to dig into it a bit.
Previously I wrote a little about the Blu-Spec CD - a red book CD burnt with a shorter wavelength blue laser. In theory, the digital signal on the Blu-Spec CD should be less prone to errors in playback.
The SMH-CD is a very similar idea: a red book compatible CD created through a new process to reduce errors on playback. In the case of the SMH-CD (Super High Material CD), the base material is a special polycarbonate plastic designed to increase the transparency on the data side of the disc. The increased transparency means less distortion on the signal read by the laser, and a more accurate playback.
I can’t find any SMH-CDs for sale, and there’s very little information about them on the internet. It looks like Prince’s catalog was reissued in Japan at some point in this format, and there’s substantial debate about the sound quality of the manufacturing process. If you know anything else about this format, toss it in the comments!
At the end of last year Sony announced a new audio disc, the Blu-Spec CD. This is an interesting idea - they’re using a blue laser (the same process as Blu-Ray Disc) to burn a standard Red Book Audio CD.
To be clear, this is not a high-res audio disc. It’s a standard Red Book CD, playable by all CD players. The difference is in the creation process.
The advantage is that the shorter wavelength of the blue laser allows for more precision in the pitting of the disc. This should result in fewer errors on playback when read by a standard CD player with a red laser. This raises an interesting question about the audibility of errors in CD playback - what do they sound like, and how well does error-correction work?