AL24 Plus Processing and the Denon 3800 (1 Viewer)

[Michael_T]

I have been looking at possibly upgrading my Technics DVD-A10, but have been turned off by the lack of the ability to select groups with most DVD-Audio players on the market without the use of a TV monitor.

I looked at the Pioneer 45A and 47Ai (found alot of things I did not like). I am now looking at the Denon 3800. I also am hesitant to bite given the many problems (specifically laser assembly problems) that have plagued this player.

Anyway - I looked at one at 6th Avenue and I noticed that AL24 processing automatically activates whether you want it or not on DVD-Audio discs.

Can someone tell me exactly what AL24 Plus processing is, and why I can't defeat it if I so choose.

At this point in time I am more inclined to stick with my Technics DVD-A10 which has served me well and trouble-free for over 2 1/2 years. I still might consider the Denon 3800 if I can find out exactly what AL24 Processing is (since Denon's marketing literature is sparse on this feature), and be assured that the new build units with a serial number 210 - 211 - 212 and after are perfectly bug free.

Any one care to help me out here. Thanks.

Mike

 

[KeithH]

Mike, did you try asking Denon Jeff about AL24 processing over on AVS Forum? If you go to the "special guests" forum there (or whatever it is called), you will see a Denon Jeff thread where he is answering various questions about Denon products.

 

[Chuck Kent]

Mike: Check out this link...http://denon.jp/europe/faq.html

It's the best Denon feature FAQ I've found yet. (If it asks you to download Japanese character support, tell it no.) The Alpha processing link is the AL24 info.

 

[KeithH]

Chuck, thanks for the link. As a '3800 owner, I had the same questions as Mike.

From the Denon link:

AL 24 Processing supports not only 16-bit digital data but also 18-, 20- and 24-bit data, as well as input data with a sampling frequency of 96 kHz.

So what happens with 24/192 data?

 

[Michael Marklund]

Michael T,

From the 3800 owner's manual (features section):

AL24 ProcessingPlus, an advanced version of conventional AL24 processing, is a newly developed analog waveform reproduction technology, and offers compatability with the high number of bits and high sampling rates of next generation media. AL24 Processing Plus compensates the input digital data to reproduce the sound with analog waveforms as close as possible to those existing in nature and with 24-bit quality. The result is increased musical reproduction capabilities of reverberations,etc at low levels, for a sound that seems to draw you into the concert hall.
AL24 Processing Plus of course carries over Adaptive Line Pattern Harmonized Algorithm & Automatic Low Pass Filter Harmonic Adjustment, the strong points of conventional ALPHA Processing. On the DVD-3800 these filters have been dramatically improved, resulting in a filtered band attenuation of over -115db and ripple within the passing band of +/- 0.00002db, a figure comparable to that of professional recorders.

Whew! As if everybody didn't know this already.
Hope that (sort of) answers your question,
Michael

 

[Michael_T]

Michael Marklund,

Yes - I read that, and that is what I termed "marketing" literature. That blurb, although somewhat informative, is to me merely marketing "speak" to make you think that AL24 processing is something you need and can't do without. That somehow, by using AL24, you are getting a better output than what was input. That we (Denon) care so much about the sound quality you receive that we are taking the native bitstream that comes into your player and modifying it so it becomes a better output - hence "a sound that seems to draw you into the concert hall".

Thanks Michael for your post, (and I decided to buy the Denon 3800 so I also saw this in the manual myself), but I wanted to know what it "REALLY" does - and why you can't actually turn it off.

 

[KeithH]

Mike, "a sound that seems to draw you into the concert hall" is marketingspeak? Naaaaaah. Why would you want to turn of the AL24 ProcessingPlus off? Do you want a sound that seems to put you in the parking lot?

 

[Michael_T]

Mike, "a sound that seems to draw you into the concert hall" is marketingspeak? Naaaaaah. Why would you want to turn of the AL24 ProcessingPlus off? Do you want a sound that seems to put you in the parking lot?

You got me!

Actually I am always "leery" of a process that takes an input signal and "alters" it in some way to make it different from what it was.

Now AL24 Processing is "altering" the input data and seems to "interpolate" an analog waveform from the digital data input.

Here is a quote from the link in a post below, taken from the site http://denon.jp/europe/faq.html:

"The processor then extrudes the rate of change in 1LSB, whether positive or negative, from the portions of waveform (A) where a change in the data has occurred and produces waveform (B). Next, the ALPHA processor uses its lower-order bit data generator to produce data for the four lower-order bits, 17-20, that should normally exist below the 16 bits as shown in waveform (C). The result is waveform (D), where lower-order bit data for each 1/16 LSB point of change is generated.
Finally, the higher-order bits of waveform (A) are added to waveform (D), producing the synthesized waveform shown in waveform (E). This waveform thus reflects the smooth 20-bit oversampled data that is reproduced with high sonic clarity."

This all sounds well and good - and I am sure it works great. AL24 takes this one step further working on not only 16 bit data, but any data up to 24 bits. But we are relying on a circuit that is changing, at least from what I read, the PCM input data into something different. From what I gather what comes out on the other side, the output, is a better quality signal than went in (and better than would normally be produced without this processing I gather), but the process does alter the original bitstream.

I guess the reason I am "leery" is for the same reason a few high-end "universal" DVD-A/SACD players would take the native DSD bitstream and convert it to hi-rez PCM for processing before placing the output through the analog outs and to your amplifier.

Anyway - I have yet to really put the 3800 though it's paces yet, so I can't really tell if AL24 Plus is preferable to normal PCM processing or not. On paper it sure seems like it.

Cheers,

Mike

 

[DanielSmi]

Maybe it upconvert everything to 96/24. That's my impression.

Daniel Smith

 

[KeithH]

Michael said:

Maybe it upconvert everything to 96/24. That's my impression.

I've wondered about that too. Anyway you slice it, it's extraneous processing. Perhaps it is effective, rather than degrading. Still, such an effective upsampling would only make sense with CDs (16/44.1) and lower-sampling frequency DVD-Audio discs (e.g., 24/48 or 24/88.2). I would have to question what the point of the processing would be with 24/96 material and certain with 24/192 material.

I am going to ask Denon Jeff about this over on AVS Forum. The question is how much information he can divulge beyond marketingspeak, given that AL24 ProcessingPlus is proprietary technology. We shall see.