So before investing in a HD621 I tried to do some testing with what I have, to see if my aging ears could possibly hear the benifits.

I tried this on both 24/96 material from my Transporter and on a the PS3 playing a few SACD's and 1 24/96 Bluray.

What I simply did was toggle HS=Y vs HS=N (down sampling 24/96,88 to 24/48,44)

This would be HD621's "best case" in the other direction. Taking 24/48,44 and making it sound like 24/96,88 as best that it can, right?

Well I hear no difference when I "down sample" why would I hear a difference when I "up sample". I've read this debate numerous times that argue the difference between 24/48 and 24/96.

This is also consistent, I believe, with VK's notes from one of Meridian's talks that "16/44" should, in theory, be enough.

My understanding is the upsampler with apodizing makes it a "Better Upsampler" by removing preringing from the upsampling process. It does not removing prering in the original recording. Does it?

If the apodizer can remove preringing from orginal recording, then why must it always be part of an upsampler?

I do hear the benifits going from 16/44 to 24/44. But beyond that I hear nothing.

- Fiddler (IMHO)

If you think listening to music is fun, try learning an instrument.
HT: G61RSL, 4x5K, 5.5KHC, 2xSC6000, Transporter, HD621, Philips BDP7501 4K, Tivo, 65" LG OLED 4K C6
Computer: Foobar2000, 5K, Mojo, HiFiMan HE1000 V2