Sony SCD-777ES /SCD-1 "Custom" or "Normal" Mode Safety

[ossidian]

Hello,

I recently acquired a Sony SCD-777ES player and have a question regarding the "custom" and "normal" mode on the rear of unit. I understand the "custom" mode will go to 100khz.
The owners manual states to avoid switching mode to avoid damaging equipment.
My question is does anyone have direct experience using the custom mode and can elaborate on experiences.

My system:

CAT SL1 Ultimate preamp (tube)
VTL MB-450 monoblock amps (tube)
Avalon Opus speakers
Thiel CS5 speakers

Thanks!

 

[KentTeffeteller]

Leaving it in normal mode would be best as far as keeping inaudible, far out of audio range content from being amplified by your system, which would make your amplifier strain more under load.

 

[ossidian]

Leaving it in normal mode would be best as far as keeping inaudible, far out of audio range content from being amplified by your system, which would make your amplifier strain more under load.

So then what is the purpose of the custom setting? My amp is capable to 100khz (spoke to Bea @ VTL directly) and my Avalon have the Diamond Tweeter (100khz) "upgrade", so if my system does not benefit then who's system would?

Are individuals hearing sonic differences in the custom mode or just a placebo effect?

 

[KentTeffeteller]

Don't really know. See how it sounds with and without.

 

[ossidian]

The switch in back for "Standard" and "Custom" actually controls the anti-aliasing filter used for the DSD data stream on the SACD's. Because of the much higher sampling rate of DSD (2.8224 Msps as opposed to the 44.1 Ksps for a redbook CD) the cutoff point the anti-aliasing filter can be much higher than the 22.05 KHz used for CD's. This means that many of the ill effects of the anti-aliasing filter on the audio band signal can be reduce by setting the DSD anti-aliasing filter at a higher frequency. Now in principle the DSD anti-aliasing filter could be set at 1.4112 MHz, however this is probably overkill for reducing the ill effects on the audio band (20 Hz - 20 KHz). So in the "Standard" position the anti-aliasing filter for the DSD begins to slope off at 50 KHz with a gradual slope. Switching to "Custom" moves the filter slope off point to 100 KHz. Sony was concerned that if there was too much signal in the frequencies above 50 KHz that some amplifiers would react by oscillating and perhaps damaging the amp in doing so. I have not heard of any amps having this problem when using the SCD-1 with the filter in the "Custom" position.

Author: Tony Plachy