PCM Setting on Receiver

[DrJ]

I have a Denon AVR-3300 receiver. It has a PCM setting for playing digital signals that subtly but definitely increases the apparent dynamic range of the music compared with the "Auto" or regular setting on the receiver, particularly for recently mastered CDs. For example, 24 bit/96 KHz remasterings in the Verve Master Edition series sound much better with this setting. Nothing as dramatic as the difference between CD and SACD or DVD-A, but definitely an improvement. Truer bass, more shimmer at the high end, and also greater separation and sense of depth with truer soundstage imaging. A bit less of that "compressed" sound when playing older CDs (although it definitely won't make a silk purse out of a sow's ear).

Now, I know that I am not hearing the music at true 24 bit/96 KHz resolution, since standard CDs, by my understanding, ultimately require "downsampling" (to 16 bit I believe) to be played (as opposed to SACDs), whether PCM mode is used or not. But my owner's manual says nothing about how this PCM setting works, and the Denon Web site info I could find says something about the 2-channel signal being routed through more D/A converters than usual, resulting in improved sound. But I'm just not clear on how that could fundamentally change anything - since ultimately there is still the downsampling issue.

Can anybody in the know out there clear this issue up? Obviously it's not a big deal, since the sound is better and that's all I really care about, but my curiosity is piqued!

[Claude]

Maybe these reviews give an answer:

http://www.homecinemachoice.com/testbench/...nAVR-3300.shtml

http://www.audio-ideas.com/reviews/receive...n_avr_3300.html

Like you say yourself, the fact that a CD has been remasted at 24 bit/96 KHz will not change anything on the CD playback side, because the digital signal on the CD is always 16bit/44.1kHz. So it's a pure coincidence that those CDs sound better with a certain setting of the D/A converter

[DrJ]

Thanks Claude. No real revelations in those reviews, but I appreciate your comments.

I had done a Web search before posting and couldn't find much, but just now searched again since you found some reviews I had not. Had to use a whole bunch of search strategies on Google, but finally found the answer on page 3 of this .pdf document:

Denon PCM Mode

This makes sense, because in doing my comparison tests I used the Pioneer DV45-A universal player, which does allow 24 bit/96 kHz output (no downsampling)! My multidisc Onkyo changer does not. So this probably explains why I am hearing the difference, which as I mentioned is most prominent on 24 bit/96 kHz remastered discs (as I mentioned the older discs don't sound a lot different, maybe somewhat but probably just because I was using a better CD player). They talk only about DVDs here, though, but the tech manual is probably several years old (the AVR-3300 has actually been discontined) and I don't think 24/96 CDs were even being made then. So I have to believe that if a standard CD has the high resolution information, and your player doesn't downsample it (which is true on both accounts), then the receiver in PCM mode is probably passing the info on without loss of resolution.

I also used my wife as a gold standard, as I always do when I'm trying to decide if I'm "hearing" the sales pitch or a real sound difference...I also did a blinded comparison with her. She couldn't really care less about audio quality but has a great natural ear. She could definitely hear the difference, nailing the correct setting every time.

Edited June 25, 2003 by DrJ

[mgraham333]

DrJ:

I have the same receiver and love it. I am gaining interest in SACD and was happy to (re)discover that my receiver had the necessary inputs.

I haven't played much with the PCM mode, but will check it out - this sounds interesting.

[DrJ]

Cool, let me know what you think - maybe I'm hallucinating!

I would like to claim that I had great foresight in buying the AVR-3300, but I didn't - I just loved the way it sounded and its design. It's really fun to keep discovering at intervals just how much vision Denon had quite a few years back (in receiver technology time!) when they designed what was really a very moderately priced receiver, such as the capability for 6 channel SACD inputs with direct signal pass-through, the direct 24/96 pass-through option for DVDs and I presume standard CDs, etc. I think I made a much better purchase than I ever realized I was making at the time.