Originally Posted by Syles
The vast majority of my digital audio collection is 16/44.1 CD rips in FLAC so will leave 518 set on 16P24.
Quote
You could set up a phantom source for the 24 bit files you have, so allocating another one of the 12 inputs to the physical input the computer is using
Thanks for the suggestion. Clever workaround.


Originally Posted by Krazywaffle
Will do some research to see if 568.2 de-emphasizes incoming digital audio.
Quote
I'm pretty sure it doesn't, de-emphasis in the digital domain negates the benefits, the gains come in reducing the HF in the analogue stage of the DAC, which reduces any HF noise by the same amount.
I seem to recall that when I used a 518 with a 568, switching emphasis in would make the sound bright; this could seem like an improvement, but in reality it's the same as turning up the treble...
OK, thanks for the insight. Based on this and DTS de-jittering it seems best to run 518 in Gain mode (within Type 1) when feeding a 568.2 Processor.


Originally Posted by Krazywaffle
Read on an older thread that +6dB seems to be preferred over +5 or +8dB as, for some reason, +6bB is the most conducive to processing. Will experiment with this today, but being that my source is a computer perhaps no additional Gain is needed?
Quote
It's because +6dB is equivalent to moving up the whole PCM data by a whole bit, so in theory the maths is very simple, but the 518 has 72-bit processing, so 1dB increases will be transparent.
I'm guilty of setting the volume on my G68 in 3dB steps; volume of 66 is okay, 65 isn't, so my start up volume is set to 66, not the default 65. I'm probably not the only one who does this!
Good to know! Will experiment with increasing gain. 568.2 generally runs in the 60-75 range depending on source material. Would it be ideal to use 518 to reduce gain so that 568.2 runs closer to 87 (unity)? Is this reduction in gain by 518 any different than just reducing the output volume from computer source (only digital source with volume control)?


Originally Posted by Krazywaffle
Thinking I’ll not run my DTS source through 518 as there doesn’t seem to be any advantage to doing so (eg, will just go directly into 568.2mm via Toslink).
Quote
From above "If you have a Meridian 518 Digital Processor, this will de-jitter a DTS signal for optimum sound quality", so may be worth it, especially over optical.
To clarify, when DTS sources trigger Bypass (via DTSCD setting) in Type 1 this still applies twin PLL de-jittering to signal? On page 20 of 518 manual it states: “Bypass transmits all 24 bits on the input to the output without any processing”. So it seems the question is: is DTSCD mode (DTS displayed on front panel) the same as Bypass mode (wherein all front panel controls are disabled)? If so, then it seems that the 518 does not de-jitter DTS signals as these are automatically bypassed.


Based on this helpful feedback it seems best to run 518 as Type 1 in Gain mode with 16P24 enhancement (manually switching to 24P24 for 24-bit audio files) for 2 channel digital audio sources and continue to pass DTS signal through for potential de-jittering.

Next up is experimentation with the various dither curves. After ideal settings are found will then remove 518 from chain to assess how the same digital sources sound when connected directly to 568.2 via 3in1out Toslink switcher (i.e., 568.2 de-jittering and Shape C dithering only as opposed to 518 de-jittering and dithering before 568.2 de-jittering and dithering).

Thanks heaps!

PS Audio PowerPlant 300|Dual 1229|McIntosh CS8 x2|Phase Linear 1000| McChanson dual mono preamp (EZ81/6SN7/6V6)|Meridian 861v4LPS, 518, 502, 598, M60, HD461|PS5|Airport Express gen2|2014 Mac mini|2x Tag McLaren 125m > DCM TimeFrame 400 & custom Diatone P450 boxes (fronts)|Axiom (NZ) > dbx SW15 (sub)|B&K AVR202 > KLH T312D & Paradigm ADP150 (rears)