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Posted: 27 Oct 2015, 21:24 

Ok...so I know I've been inactive for a while....and I came here to mostly check up to see what's happened during my long absence (plus I have a mildly related LD post to write in a little while). But I was excited to see a forum for SACD; because as an audio guy I've spent a lot of time studying the format and whatnot. I've actually authored an SACD disc a time or two using the so-called "SACD-R" format. Most of you might know this, some of you might not....so I'm going to share what I know.

Ok, so as you probably know, SACD uses the DSD format to store it's audio; and you've probably read where it's a 2.8 mhz sampling rate. "Wow!" you might think; "that's a lot more than 44.1khz i'm using on my lousy CDs"...well calm down there Fido. There's one little thing people tend to really overlook when discussing DSD.

DSD is a 1-bit format.

So what this mean? This means that rather than storing audio using a PCM method; in which discreet samples store an integer value that correspond to a voltage; 1-bit formats store the "change" in your waveform. It's functionally similar to delta-sigma modulation; and 1-bit is also how 99% of DAC's actually convert the digital audio to analog audio. This was done becuase, back in the 80's; building a DAC that worked directly from PCM to analog was difficult; plus the technology of the era was very limited and dynamic range was crap. The term for this is "oversampling DAC". The DAC converts your PCM signal in to a 1-bit delta-sigma stream; which can be converted to analog using something as simple as a low-pass filter to remove the ultra sonics.

The way it works is you have a sawtooth wave generator that is capable of running at an insanely fast rate; and every time you trigger the generator, it switches "directions". The idea is that you basically trigger this sawtooth wave generator (which is outputting a voltage) so that the sawtooth stays "right around" the area of your analog wave form. The output would be, from an analog stand point; a representation of your audio with a super-sonic waveform superimposed on it. IT's also worth mentioning that filters can be built easier for higher rates than lower rates; so dealing with a 2.8mhz output rate means you get to use a relatively simple filter on the output. Remove the ultrasonic sawtooth from the signal; and you're left with a relatively clean analog waveform.

DSD is basically storing this 1-bit audio format on the disc rather than enumerating it to PCM like we do for CD. So what advantage is this?

Well..the main advantage is if you're storing your audio in a 1-bit format already; you don't have to convert it to a 1-bit stream; you can just send it directly to your DAC. As I mentioned; 99% of DACs on the market (basically every dac capable of more than 16-bit) use an oversampling method; storing your audio in 1-bit actually eliminates a conversion step. Part of the perceived enhanced quality is because of that; converting PCM to DSD and vise-versa is not an easy or accurate task. While you do have this advantage; there are a number of disadvantages.

For starters, even with the insanely high sampling rate; the 1-bit suffers from horrible dynamic range in general. SACD overcomes this by using noise-shaping; a chunk of inaudible ultra-sonic spectrum contains nothing but noise...basically dithering. This allows you to increase the apparent dynamic range of the recording. It's used in GIF's to make the color downsampling look better; it's also used in better PCM Editors to convert 24-bit audio to 16-bit audio without encountering quantization noise...you put enough noise somewhere where it won't be heard so that you maintain an amplitude over the quantization level.

This is why it has been said "SACD is only as efficient as 20-bit 88.2khz". Basically, just about everything above 40khz in the audio spectrum is noise. It's not that the format itself cannot respond to something that high; in fact I've seen sweeps well over 100khz in a DSD file; it's just you have way more noise than signal up at that end. Most SACD players, in reality, have a 30 to 40khz lowpass filter.

The other issue is that a lot of people seem to want to play back DSD files on their PC without having a DSD capable DAC. So you're going though a DSD->PCM step..just to go from PCM->1-bit in your DAC. It's a pretty wasteful process; and it's one of the reasons people who attempt this start to say "DSD is stupid". It is not a horrible process as long as you realize what you are doing and use good filtering; I myself have a couple of DSD recorded tracks that have been converted to high-rate PCM and enjoy them just fine.

Some players, especially multi-format players; have a lousy habit of converting the DSD to 24/88.2PCM before decoding them; adding to the mess.

Now...another small truth about SACD...things hardly ever say true DSD. One of the problems with 1-bit files is that you cannot edit them; you can do some simple stuff to them; but the usual amount of post-production done to a CD during the mastering phase cannot be done in the 1-bit domain; likewise, you cannot record sessions in 1-bit, mix in 1-bit, and export in 1-bit. There are two ways they've worked around this; one of them is using a DSD format with a higher bit-depth. However, those stations are very expensive; and there is still the issue of we live in a largely PCM world. So...they came up with something else; DXD.

So what is DXD? DXD is basically high-rate PCM; specifically, it's 24(maybe 32) bit PCM audio at a sampling rate of 352khz! Whenever you are dealing with stuff recorded in DSD; 99% of times it gets converted to DXD PCM for production. In fact, I was told by one guy that just about *every* SACD on the market; at some point in the chain; was PCM.

Whether any of this is enough to turn one off of the format depends on your personal preferences. I happen to like DSD as a format; it, in a way..is future proof. You can take one DSD source and convert it to a higher rate PCM while..in theory..enjoying some of the benefits of being a higher rate. There is also a slight fact that most ADC's actually capture audio to a 1-bit pulse stream before that is converted down to a PCM rate. I have seen *many* 24/192khz files that show dithering noise in the upper end of the spectrum; a tell-tale sign of conversion.

Basically, it all boils down to how many times do you want to push the audio through format conversions; and whether or not you think what the professionals are using, or even what you using; do an adequate job of it. Of course, there are higher rate 1-bit formats out there; like 5.6mhz DSD128 and I've even seen some 11.2mhz DSD256 devices floating around out there.

Now...funky facts about SACD.

SACD medium is, physically, a DVD. The main difference is that the discs incorporate pit modulation as a form of copy protection; and as a result...cannot be read by anything except a SACD player. That's why he only way to extract DSD from an SACD is using an older hacked PS3; it not only contains the drive capable of reading SACD...but the software hacks let you get the DSD audio out. But they are 4.7GB/layer, just like a DVD.

The format is actually 2.8mhz *per channel*; this means you need 5.6mbps transfer rate for a 2-channel stereo content. If you do the math, this means you need close to 15mbps to support a 5.1 stream; much higher than a DVD itself can physically transfer per second. To overcome this; there is a special lossless codec for DSD called DST (digital stream transfer); it manages to get really good compression (2.5:1 to 3:1) on the content. It's this DST stream that is decompressed in the player to obtain a 5.1 DSD stream. It is mandatory on 5.1 audio; it is optional on 2.0 mixes. Some hybrid discs use DST on stereo content, just for space constraints.

Of course, by that math; you only need 5.6mbps to store this audio; where as 24/192khz requires 9.2mbps...then again it's not really all that better than 24/96 when you take in to account the noise-shaping; which only requires 4.6mbps.

Unlike the audio CD, which is a set length; the amount of audio you can put on a SACD is only limited by how much space you have. When using DST compression; you can actually cram about 4 or 5 hours worth of music on a 4.7GB disc. As an example; Hotel California in 2.0 DSD consumes about 1.3 GB of data; after conversion to DST, it's under 600MB. But don't try to burn that to a CD-R and expect it to work; the SACD players know the difference in the mediums (or at least my Oppo does). Even when you burn your own SACD (after obtaining the software to convert to DSD, merging your DSD files in to one large one; and figuring out the authoring software), it still shows up as an invalid disc on your PC.

I think I've said just about everything I can on the subject.

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 Post subject: Re: Diving in...
Posted: 12 Sep 2020, 01:51 

You really won't get any advantage to audio unless you have a nice amp and speaker setup.

If you are using lower quality then you won't really notice.
Good luck on getting a player and enjoy the format if you do succeed.

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 Post subject: Re: Diving in...
Posted: 12 Sep 2020, 02:55 

Hello Xander,

I am also in Scotland & I fully understand the concerns regarding LD players arriving damaged, not much fun when that happens.

Your best bet is to pick the player up from the seller - you get the chance to see the unit in action & avoid the "it was in perfect working order when I sent it out" scenario which can happen.

You may have to travel a bit of a distance though.

I have picked up a few players in the past from north of the border so they do turn up but not so much now.

Sadly there is a seller in Scotland that should be avoided. If you get the "sorry can only send out, no personal uplift" from a seller in Scotland please take care & perhaps best avoided.

Good luck with the player hunt.

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Posted: 21 Sep 2020, 14:51 

without pics its hard to say.
get some thin wire to make jumpers and solder to fix the remote, if the pad is truly bad then you will have to figure a new repair or new remote.
most can be had for 10 bucks and most are all compatible.

as for the noise, sounds like it may be slipping on the pad???
I've been having some issues with all my players recently and need to open and clean the pads so the disc won't slip.
thats my guess on the player.

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Posted: 21 Sep 2020, 15:00 

Yes could be the belt also, not sure but that goes bad too.

As for players it will depend on what you are looking for, I don't know much about those players from being to early for my brain right now.
Can't remember if you wanted pal ntsc combos either?

Working is the most important.

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Posted: 21 Sep 2020, 17:46 

CLD-1750 < CLD-2950 < CLD-99

The jump from the CLD-1750 to the CLD-2950 is much larger than the hop from the CLD-2950 to the CLD-99. If the CLD-2950 +PAL version of the CLD-D703, you would only gain AC-3 RF out and better S-Video.

I think the CLD-1750 is single-side so keep that in mind.

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Posted: 21 Sep 2020, 19:04 

The image of the 99 blows away the others. However it’s also less reliable.

Buy all three and learn to fix stuff. That is the ONLY way you’ll be a happy LD user. If that scares you, give up now.

Im not in PAL land but it seems like even in the UK half the discs are NTSC. As an American I’ve imported half my collection but never had any interest in PAL LD except for some music titles that have all rotted. IMHO PAL LD is %99.99 worthless.

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Posted: 22 Sep 2020, 00:34 

The single-sidedness of the CLD-1750 does appeal because it presumably means one less mechanical thing that can fail
Additionally they can have more alignment issues. I just got a DVL-91 where side A was good but side B was way off.

If you go the CLD-99 route, make sure it comes with the correct remote: CU-CLD117.

How much is the CLD-1750?

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Posted: 22 Sep 2020, 01:48 

I've got to say I love the single sided players, but also love the double sided players.

It all depends on what you can afford.

You just have to understand that there is a very limited amount of parts, I recently fixed a remote for my CD player, bought some parts the springs and flat tabs
for the batteries and soldered them, it was a buck for 10 pieces.

So you can spend thousands but when there are no parts you are SOL.

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Posted: 22 Sep 2020, 05:24 

If I were you I'd go for the cheaper CLD-1750 rather than the CLD-99. You already have a great player in the CLD-2950. I own both the 1750 and 2950 and the former holds up well. As you said, the fact it's single sided is actually appealing in some ways because there's less that can go wrong.

Side note, but holy s**t I had no idea LD players were so expensive these days 0_O

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Posted: 23 Sep 2020, 00:54 

Has to do with centering, if it can't play a CD then centering is off.
Unless there is something else I forgot or don't know of.

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Posted: 23 Sep 2020, 01:12 

It seems like it might be a common issue in these late 80's early 90's single-sided units. It could just be bad luck, but I've had at least 3 that would not play CDs. A CLD-M(something), CLD-V2400, and either a CLD-1070 or 1080. I also will see them for sale saying the same thing.

If I see any crosstalk and it will not play a CD, I adjust the pickup inclination (which is usually really off) and that can fix it. If not, you have to look at centering which is not fun to adjust- even with an oscilliscope.

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Posted: 23 Sep 2020, 15:18 

It has been a little more than 3.5 years since the last upgrade (see https://forum.lddb.com/viewtopic.php?f=2&t=6849) and the hardware is not really an issue... but the Operating System is (Debian 8: not maintained anymore since June).

Updating the whole OS from Debian 8 to 9 or 10 on the main server is quite scary.
Doing a parallel validation and switching to the new server when ready is much, much more recommended.
It just requires to pay for both during the migration preparation time, some of the donations will be used for that.

=> http://163.172.34.149/

For most users the difference will only be a 4~24h downtime while the DNS get refreshed.
But for me, it will be several busy evenings and weekends :-P

Julien

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Posted: 25 Sep 2020, 08:39 

Just back from the Service Center where they probably still didn't fully comprehend this over excited gaikojin (me) showing up with a mint LD-S9 for servicing and inquiring about a lot of things!

The person before me left a CLD-R5 for servicing as well.

IMG_1770.JPG
IMG_1769.JPG
IMG_1768.JPG


But the bad news (for now) are:

1/ Do you still have spare parts available to buy?
=> We do not sell internal repair parts.

2/ What will happen to the parts/stock after 2020/9/30?
=> It will be discarded.

3/ Do you still have the User/Service manuals available?
=> We do not sell service manuals.

I'm not giving up. I'll make a serious business offer to purchase the remaining parts inventory in bulk.
For this I need the service desk/center to escalate higher in the hierarchy.
I gave them my LDDb business card if it can help :-)

I can be reaaaaaaallllly annoying until they give up :-P

Julien

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Posted: 18 Oct 2020, 22:57 

PAL/NTSC players are mostly meh. The 915 is OK, but has worse ringing than similar models, and the PAL/NTSC DVL's might be alright.

Generally with NTSC before the 915, the circuitry is much worse than in NTSC-only players, especially when the PALB board is in use (which may or may not require rewiring the player). The 2950 has basically the same mechanics as the 99, but the electronics are worse than the baseline NTSC-only 503 (analog TBC, etc)

As for PAL, it's mostly that nobody ever made a really good PAL player, ever. They *all* suck compared to what PAL LD can do.

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Posted: 20 Oct 2020, 04:52 

Yup, i meant 925... the lower end ones were the 315 and 515 (which still have the dodgy AF PALB board), so my brain mixed 'em together.

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Posted: 22 Oct 2020, 17:11 

Well I've recently re-acquainted myself with the 2950 (have acquired a extensively refurbished and re-calibrated specimen) after nearly 20 years, this was the first LD player I owned from new but I replaced it with a 925 in the early 2000s. I had a big shock when I compared it recently to my 925s as the PQ is far superior to at least my eyes, especially in terms of the 2950s much reduced chroma noise. It delivers a much smoother yet equally as detailed image as the 925 and with film based material it really does produce a very filmic image. An example on video is Pink Floyd Pulse, the chroma noise at times on this disc can be quite distracting (the DVD isn't much better either) when spun on a 925, switch to the 2950 and it's virtually non-existent! this is with the HQ Circuit switched out which btw is a lot less severe than the one fitted to the 925 which totally impares the PQ although I'd never advocate using either tbh. I won't go into the audio performance for now but let's just say that once again the 2950 takes the crown here too!

Anyway the only reason I purchased this 2950 is that I still own a significant sized PAL LD collection all my NTSC discs are handled by an X9 and previously an R7G but I recently decided to make a back to back NTSC comparison 2950 v X9; the thing is there was just no need to do so really for as soon as the 2950 spun up and displayed an image it was a total disappointment, what is actually a fine PAL machine doesn't even equate to average where NTSC playback is concerned - the 925 is perhaps a tad better here but not by much so really if it's high quality NTSC only playback you require non of these machines are going to deliver for you sadly. Then again if your 2950 is looking noisy on PAL playback it really sounds as though it's underperforming. If I were you I'd start looking for a nice CLD-R7G, using its S-video out I'd guarantee the PQ will put a big smile on your face once you've set the comb filter and other NR adjustments to your own personal taste :thumbup:

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 Post subject: Re: Denon/Pioneer player
Posted: 23 Oct 2020, 00:20 

Yeah most Denon's were Pioneers.

Also for what it is worth, I would choose a CLD-S201 based player over a CLD-S104 based player any day.

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 Post subject: Re: Denon/Pioneer player
Posted: 23 Oct 2020, 01:37 

This is an OK player except for the relatively paper thin chassis that gets looser with age. The vibration is visible in the picture and also very audible, especially for CAV discs. It was at one time the crappiest player Pioneer ever made but then they dropped the price another $100 soon after and made the 104.

For clarity's sake: were you referring to the CLD-S350 or the Denon LA-2050 here? Or... is that basically a meaningless distinction due to the degree of similarity? I'm reading it as the S350 but despite the reference to Pioneer making it, I guess you could equally be referring to the Denon since I *think* they were simply Pioneer manufactured units rebranded.

Yes. They are all the same deck except for some ports and maybe voltage selector. If you have one of the Pioneer versions you’ll see that they all have the same manual.

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 Post subject: Re: how is it going?
Posted: 23 Oct 2020, 03:02 

@ Julien thats the most creative avatar I have seen on the internet, and I have been on the internet for a long time!

"Most users ever online was 269 on 21 Oct 20"

woah! This forum has been online for what? like 20 years and its most active users were yesterday?! If LD collection is on the rise, this might be the time to start hoarding before prices shoot through the roof!

Where are you located again??? I'll sell you some LDs to hoard..........

Are you selling here on the LDDB store? didn't notice your username in there.
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