Archimago wrote: > Interesting history there Arny... I assume the effect must have been > transparent. > > Also I presume there's an AD/DA in the device. What kind of conversion > quality are we looking at with the ADD-1 back in the day for these > LP's!? > > I'm sure Michael Fremer would have no trouble identifying these > digitally compromised LPs :rolleyes:.
I can only talk about what I read from the dB article, what was SOTA at that time, and analysis of the measured evidence that I observe. Back in the day we had very little analog test gear that was accurate enough to make judegments about gear this good. It was indeed composed of a pair of discrete ADCs, probably sucessive-approximation, the digital delay line was probably based on shift registers implemented in TTL, and a pair of discrete (probably R2R) DACs. The brick wall filters were no doubt analog, probably made up of lots of little coils and capacitors. They were unlikely to have been minimum-phase or very accurate. The notch in the recording of low level signals suggests what were called Eliptical Filters. But it performed so much better than analog. For example it passed the keys-jangling test, and it took 30 ips half-track to do that in days when 15 ips hafl-track was the usual practice. ------------------------------------------------------------------------ arnyk's Profile: http://forums.slimdevices.com/member.php?userid=64365 View this thread: http://forums.slimdevices.com/showthread.php?t=108499 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
