The SCD-1 is different from some CDPs, insofar as a Synchronous Time Accuracy Controller (S-TACT) chip that is located next to DAC in the analog section of the player, isolates master-clock generation and signal voltage-pulse generation in one chip at a remove from noise propagated by high-speed operations in the RF & digital sections. The stock quartz oscillator chip is located in the analog section 1" from the S-TACT. In a clock upgrade the stock oscillator chip is removed & replaced by a lead-out to a 45Mhz clock PCB. To eliminate the possibility of noise induced by capacitive effects across the PCB, I lifted Xin pin of the S-TACT from the PCB and made short ptp connections between Xin & clock PCB. So in view of Sony's set-up that theoretically isolates master clock from digital noise, I am inclined to consider that audible improvement may be largely due to accuracy of the replacement clock.
I've heard audible improvements upgrading power to clock, and also after upgrading power and various passive SMD components around DSPs, PLLs, and motor/servo in the digital section. Whether this is due to reduced jitter or to reduction of other noise I cannot say. But I have no doubt that improvements in the digital domain other than clock are audible as well.
Esoteric sells an optional out-board clock for its top player that's accurate to a half part per billion; magazine reviewers claimed to hear a difference. I know a fellow in Japan who makes similar claims using an external pro signal generator to clock his player.
All this might sound like an exercise in diminishing returns but my ears tell me otherwise.
I've heard audible improvements upgrading power to clock, and also after upgrading power and various passive SMD components around DSPs, PLLs, and motor/servo in the digital section. Whether this is due to reduced jitter or to reduction of other noise I cannot say. But I have no doubt that improvements in the digital domain other than clock are audible as well.
Esoteric sells an optional out-board clock for its top player that's accurate to a half part per billion; magazine reviewers claimed to hear a difference. I know a fellow in Japan who makes similar claims using an external pro signal generator to clock his player.
All this might sound like an exercise in diminishing returns but my ears tell me otherwise.