jbc;206985 Wrote: > My experience - the DAC in the SB3 is not bad. I think it's probably > fair to compare it to a $500 or so CD player. >
The SB3 is not bad at all! However, my feeling is that things are not that simple. It's not a matter of DAC only. In view of the data sheets, the PCM1748E inside the SB3 is a $1.20 DAC, with a 100 dB SNR and 0.003% THD. A flagship PCM1792A, to stay at BB, is a $9.95 part, with a 127 dB SNR and 0.0004% THD. And the price doesn't include the mandatory I/V conversion circuit. So, although a decent performer, the DAC in the SB3 is definetely a low cost one. However, it sounds surprisingly well for a cheap DAC. If you want to (try to) explain that, you have to look at the SB3 in a whole as a complete player, and as such other parameters -I mean jitter at first- are to be taken into account. What we have here is a low cost DAC fed by a top-notch transport. Not only the jitter figure of the SB3 is respectably low, but I feel (and if only I could measure it...) that this jitter is mostly random (as one could expect from a decent crystal quartz oscillator), instead of far more annoying data correlated jitter that even the best drives are prone to deliver, not to mention the negative effects of the S/PDIF. The point is that for a given RMS or peak-to-peak jitter figure, it's not esay to decide which part is random and which is not, and I suppose that it may be an explanation for sounding difference between drives with similar amount of jitter. Most of the drives out there present a balance, in terms of cost and performance, between the transport side and the DAC side. So a mainstream drive stuffed with the same DAC as the SB3 will surely be a mid to low range one. The SB3, on the other hand, is an unbalanced product: one of the best "transports" available, and a cheap DAC. The total combination yields a fairly decent product, with a lot of room for improvement in the DAC side however. As many other users, I can experiment it day after day with an external DAC. I've also in the way some kind of SB+ from my own, by replacing the PCM1748 with a pair of AD1865, wired through I2S. Bye bye S/PDIF! JLM -- jlmatrat ------------------------------------------------------------------------ jlmatrat's Profile: http://forums.slimdevices.com/member.php?userid=10656 View this thread: http://forums.slimdevices.com/showthread.php?t=35642 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
