millwood, a cheap DVD-ROM can make stupid things.
Like the motor noise Nuuk was talking about, or taking 20 seconds😱 to read a CD's TOC.
Today it's 20 seconds, one month later it's 40 seconds, and finally it stops reading.
Ridiculous.
And what about CHEAP switching PSUs on audio devices?
Dreadful.
In a while you'll find out that to tweak this thing you won't even use the box, it's too crappy.
Value for money?
Oh please...
Like the motor noise Nuuk was talking about, or taking 20 seconds😱 to read a CD's TOC.
Today it's 20 seconds, one month later it's 40 seconds, and finally it stops reading.
Ridiculous.
And what about CHEAP switching PSUs on audio devices?
Dreadful.
In a while you'll find out that to tweak this thing you won't even use the box, it's too crappy.
Value for money?
Oh please...
analog_sa said:
Yeah. on a 2nd thought, Microsoft Office installed from my cheapo Brand A runs doesn't look as sharp as the same package installed from Brand B.
:0
analog_sa said:
I'm in too.😀
millwood, you won't notice difference on CDR copies made on cheap CDR drives and/or at insane writing speeds (more than x4 for audio CDs) IF YOU DON'T HAVE A GOOD SOURCE.
On a crappy DVD player of course you won't notice.
And the problem is not your ears.😉
carlosfm said:
I would like to retract my earlier statement. I have indeed noticed that pictures burned on crapy CDRs look positively gray, software packages burnt on crapy CDRs, or through crappy CD burners, or installed on crappy CD-Rom drives, don't look right, and sometimes have missing features.
I am sure you guys have the same experience, don't you?
🙂
millwood said:
Is JITTER still such an obscure thing?
At least understanding what is it and how to minimize it?
millwood, we're talking AUDIO CDs.
carlosfm said:
I have absolutely positively zero idea about jitter. do you know what it is? and specifically how is that such a deficiency in those el cheapo DVD players?
on the quality front, even if you buy brand name and supposedly high-end stuff, you can assure yourself of a working units. Marantz AVR for example had audio drop outs on digital inputs; Denon DVD players had lip sync problems, as some pioneer ones.
the differrence between a no-name dvd player and a brand name dvd player is much smaller than that in the analog land (like analog amps).
Everyone is doing this. East Tech is famous for example for OEMing for the likes of ATI and Shoreborn. My Parasound is made in China as my Signature.
BTW, Denon & Marantz and McIntosh is building a factory in China to function as its global manufacturing hub.
We better get used to it and don't hold on the perceived notion of brand names and being taken to the bank by marketers.
the differrence between a no-name dvd player and a brand name dvd player is much smaller than that in the analog land (like analog amps).
Everyone is doing this. East Tech is famous for example for OEMing for the likes of ATI and Shoreborn. My Parasound is made in China as my Signature.
BTW, Denon & Marantz and McIntosh is building a factory in China to function as its global manufacturing hub.
We better get used to it and don't hold on the perceived notion of brand names and being taken to the bank by marketers.
Comparing apples with apples.
An =audio= CD has relatively little provision in the way of error correction - worst case is the error is interpolated or muted and you hardly hear it.
Bottom line is this - I think if you read a data CD then you are going to get an error-free result. If you read an audio CD then the result may depend very much on the disc and the individual player.
A =data= CD is sprinkled with lots of extra bits for the purpose of error correction. IIRC the resulting bit error rate is 1 in 10^12 or suchlike. If the CDROM hardware doesn't co-operate to make this happen then your files are going to have problems left right and centre, something that will be immediately obvious. Generally speaking though, even dirt cheap CDROM drives give no problems with data CDs.millwood said:
An =audio= CD has relatively little provision in the way of error correction - worst case is the error is interpolated or muted and you hardly hear it.
Bottom line is this - I think if you read a data CD then you are going to get an error-free result. If you read an audio CD then the result may depend very much on the disc and the individual player.
It's The Pits.........
I read a study somewhere on the net about the cd-rom burner drives being quite important.
Bad burners place jitter on the burned disc, and this becomes audible on replay machines.
Recorded pit depth and transitions quality are factors , and so is disc rotational speed stability during recording of audio discs (1x-4x recomended).
IIRC Plextor drives were rated as best recording drives in terms of playback jitter performance of the recorded disc.
Silver, gold, blue, black etc discs were also rated as giving differing playback jitter performance.
Commercial release (silver) discs have measurably different jitter performance according to pressing plant, mother mastering etc too.
Eric.
I read a study somewhere on the net about the cd-rom burner drives being quite important.
Bad burners place jitter on the burned disc, and this becomes audible on replay machines.
Recorded pit depth and transitions quality are factors , and so is disc rotational speed stability during recording of audio discs (1x-4x recomended).
IIRC Plextor drives were rated as best recording drives in terms of playback jitter performance of the recorded disc.
Silver, gold, blue, black etc discs were also rated as giving differing playback jitter performance.
Commercial release (silver) discs have measurably different jitter performance according to pressing plant, mother mastering etc too.
Eric.
Originally posted by millwood
I have absolutely positively zero idea about jitter. do you know what it is? and specifically how is that such a deficiency in those el cheapo DVD players?
Jitter is everything.
There is infinite information on this forum and all over the net about jitter- go knock yourself out.
Eric.
I have absolutely positively zero idea about jitter. do you know what it is? and specifically how is that such a deficiency in those el cheapo DVD players?
Jitter is everything.
There is infinite information on this forum and all over the net about jitter- go knock yourself out.
Eric.
Well, I probably shouldn't touch this thread, but I've spent the last 2.5+ years designing DVD players for numerous brand names, and I've seen the industry evolve from the inside... plus I see a lot of misinformed posts in this thread. But, I'll give a brief breakdown of what you get when you buy a higher priced DVD player...
1. Better laser head and transport mechnism (motors, spindle bearings, tray, manufacturing tolerances). Good mechanisms will last longer, be quieter, seek faster and more accurately, and deliver lower bit-error rates during playback. They're also more tolerant of damaged discs. Good lasers will similarly give better read performance, tracking and focus, and they'll last longer too.
2. Better front-end circuitry (laser and motor control servo, read-channel decoding).
1 & 2 are directly reflected in how well the player can do disc detection, the playback error rates, tolerance of surface imperfections on the disc, and speed for things like DVD layer change. I did a fair amount of work with DVD front end design, tuning and so on, and they are difficult to get just right. This is the area where some of the biggest sacrifices are made in cheap DVD players. The R&D effort is just not done - the low-cost OEMs are relying on "prior art", just trusting that it will function.
3. Better MPEG decoder chipset. The low-cost units have no room for a decent chipset. They use the cheapest available, period. More expensive units can use better chipsets, and without going into the details, suffice it to say that DVD decoding is exceedingly complex - better chipsets result directly in better video and audio performance, and better useabilty, because care has been taken to ensure that it's all handled properly. (You wouldn't believe what some player firmware will do with audio samples...
).
4. Much, much better PCB layout and quality. Open up a mid-priced Sony and compare that to an Apex. No comparison. The Sony will likely have a 4 or 6-layer mainboard with very fine tolerances, while the Apex will use a crappy 2-layer mainboard, and 1-layer everywhere else.
5. Much better software QA and assembly-line QA. There is tremendous variance in the QA programs of different manufacturers. The software that runs inside these things is ridiculously complex, and good QA is essential to ensure playability with all the badly authored discs out there. The DVD standard is really too flexible and open, and it's created lots of problems because the title authoring has not been held to the standards that do exist. Chances are, if you have a DVD that plays fine on one machine, but borks on another, the DVD is improperly authored, and there's nothing wrong with the player. That said, a manufacturer with good QA will test each and every "special-case" title they know of, to see that it plays correctly... that's hundreds of different movies that need to be tried out, each with different bugs that may or may not show up, and tehn require subsequent debugging and software patches. Assembly-line QA will keep bad units from winding up in your hands, and also snag engineering problems early in the production phase, leading to improved quality for every player that comes off the line after that. A good rule of thumb: never buy a DVD player when the model is brand new. Wait a month or two, and then buy one. You'll get a better product, guaranteed (many models go into production before software debugging has finished, just to meet the production and delivery schedules).
Of course there's always the obvious stuff, like basic component quality and PSU quality too, but that pretty much covers it. If I had to make a recommendation for a player, I'd say buy a model that's at least a year old... the technology has gone steeply downhill since the introduction of a certain cutthroat Taiwanese chipset brand that made the $50 Apex possible about 8-10 mo ago. Sadly, all of the OEMs were forced to compete on price alone, and features, quality, and usability have all suffered.
There are other things I could talk about, such as why progressive scan deinterlacing should be done in the player, not in the TV set, and why a DCDi badge does not mean you'll get good progressive scan. Actually, progressive scan is one big bag of worms that I don't care to get into. Suffice it to say that there can be staggering differences in the quality of progressive scan conversion (3:2 pulldown, and video deinterlacing) from different DVD players, so if you have a progressive display, then it behooves one to do some research and get a player with the best progressive scan conversion possible. I recommend this excellent resource if you really want to understand the basics of progressive scan: Home Theatre HiFi. Yes, as much material is there, it's only the basics.
1. Better laser head and transport mechnism (motors, spindle bearings, tray, manufacturing tolerances). Good mechanisms will last longer, be quieter, seek faster and more accurately, and deliver lower bit-error rates during playback. They're also more tolerant of damaged discs. Good lasers will similarly give better read performance, tracking and focus, and they'll last longer too.
2. Better front-end circuitry (laser and motor control servo, read-channel decoding).
1 & 2 are directly reflected in how well the player can do disc detection, the playback error rates, tolerance of surface imperfections on the disc, and speed for things like DVD layer change. I did a fair amount of work with DVD front end design, tuning and so on, and they are difficult to get just right. This is the area where some of the biggest sacrifices are made in cheap DVD players. The R&D effort is just not done - the low-cost OEMs are relying on "prior art", just trusting that it will function.
3. Better MPEG decoder chipset. The low-cost units have no room for a decent chipset. They use the cheapest available, period. More expensive units can use better chipsets, and without going into the details, suffice it to say that DVD decoding is exceedingly complex - better chipsets result directly in better video and audio performance, and better useabilty, because care has been taken to ensure that it's all handled properly. (You wouldn't believe what some player firmware will do with audio samples...
).4. Much, much better PCB layout and quality. Open up a mid-priced Sony and compare that to an Apex. No comparison. The Sony will likely have a 4 or 6-layer mainboard with very fine tolerances, while the Apex will use a crappy 2-layer mainboard, and 1-layer everywhere else.
5. Much better software QA and assembly-line QA. There is tremendous variance in the QA programs of different manufacturers. The software that runs inside these things is ridiculously complex, and good QA is essential to ensure playability with all the badly authored discs out there. The DVD standard is really too flexible and open, and it's created lots of problems because the title authoring has not been held to the standards that do exist. Chances are, if you have a DVD that plays fine on one machine, but borks on another, the DVD is improperly authored, and there's nothing wrong with the player. That said, a manufacturer with good QA will test each and every "special-case" title they know of, to see that it plays correctly... that's hundreds of different movies that need to be tried out, each with different bugs that may or may not show up, and tehn require subsequent debugging and software patches. Assembly-line QA will keep bad units from winding up in your hands, and also snag engineering problems early in the production phase, leading to improved quality for every player that comes off the line after that. A good rule of thumb: never buy a DVD player when the model is brand new. Wait a month or two, and then buy one. You'll get a better product, guaranteed (many models go into production before software debugging has finished, just to meet the production and delivery schedules).
Of course there's always the obvious stuff, like basic component quality and PSU quality too, but that pretty much covers it. If I had to make a recommendation for a player, I'd say buy a model that's at least a year old... the technology has gone steeply downhill since the introduction of a certain cutthroat Taiwanese chipset brand that made the $50 Apex possible about 8-10 mo ago. Sadly, all of the OEMs were forced to compete on price alone, and features, quality, and usability have all suffered.
There are other things I could talk about, such as why progressive scan deinterlacing should be done in the player, not in the TV set, and why a DCDi badge does not mean you'll get good progressive scan. Actually, progressive scan is one big bag of worms that I don't care to get into. Suffice it to say that there can be staggering differences in the quality of progressive scan conversion (3:2 pulldown, and video deinterlacing) from different DVD players, so if you have a progressive display, then it behooves one to do some research and get a player with the best progressive scan conversion possible. I recommend this excellent resource if you really want to understand the basics of progressive scan: Home Theatre HiFi. Yes, as much material is there, it's only the basics.
Re: It's The Pits.........
I also read on the net that you can use certain kinds of permanent markers to improve your CD performance.
BTW, lots of internet sites talk about why cables cannot make a different.
so do you agree that cables cannot make a difference based on that?
🙂
that's why we have so many jitter experts who cannot explain what jitter is, what caused it and why it is worse in certain players than others.
mrfeedback said:
I also read on the net that you can use certain kinds of permanent markers to improve your CD performance.
BTW, lots of internet sites talk about why cables cannot make a different.
so do you agree that cables cannot make a difference based on that?
🙂
mrfeedback said:
that's why we have so many jitter experts who cannot explain what jitter is, what caused it and why it is worse in certain players than others.
hifiZen said:
thanks for such a well written post.
I didn't see you mentioning "jitter". Isn't jitter everything?
hifiZen said:
I didn't know Apex used those Taiwanese chipset. What chipsets do they use?
Front-end chipset can have a big influence on jitter level... it gets into some pretty complex details regarding the logic-level internals of the chipset, but there are many different ways to handle spindle speed control and the PLL or PLL-like system that is at the head of this function. Data buffering and intra-IC clock domains play a major role here...
PS - all these cheap DVD players are the reason I no longer have a job... for the sake of the other poor souls still employed by American DVD chipset makers, don't buy these odd-name Chinese players! Get yourself a good one (and a good player will in fact make an excellent platform for audiophile mods) made by a japanese company (I recommend Sony, JVC, and Panasonic models - in their mid to high price range).
PS - all these cheap DVD players are the reason I no longer have a job... for the sake of the other poor souls still employed by American DVD chipset makers, don't buy these odd-name Chinese players! Get yourself a good one (and a good player will in fact make an excellent platform for audiophile mods) made by a japanese company (I recommend Sony, JVC, and Panasonic models - in their mid to high price range).
Hi Chad, thanks for your input.
Can you detail the differences between a good pickup and a bad one?, and what goes wrong with pickups ?.
Eric.
Can you detail the differences between a good pickup and a bad one?, and what goes wrong with pickups ?.
Eric.
during the VCD days, Cirrus had a huge chunk of the Chinese market. and I suspect that they still do today in DVD. Zoran also been an aggressive player in that market.
That's a pretty high order to accomplish. I don't believe in sanction / boycott. To have sustainable success, one has to have a desirable product at a competitive price. If you cannot do that, nothing can save you or your job.
BTW, is there any data on perfromance benchmarking of various chipsets?
hifiZen said:
That's a pretty high order to accomplish. I don't believe in sanction / boycott. To have sustainable success, one has to have a desirable product at a competitive price. If you cannot do that, nothing can save you or your job.
BTW, is there any data on perfromance benchmarking of various chipsets?
Originally posted by millwood
I also read on the net that you can use certain kinds of permanent markers to improve your CD performance.
BTW, lots of internet sites talk about why cables cannot make a different.
So do you agree that cables cannot make a difference based on that? 🙂
The article I spoke of included jitter measurements, including cd pens making measured differences.
that's why we have so many jitter experts who cannot explain what jitter is, what caused it and why it is worse in certain players than others.
The reason that nobody is explaining to you is that jitter is an elementary concept, and easily researched by yourself on this forum and on the net.
Eric.
I also read on the net that you can use certain kinds of permanent markers to improve your CD performance.
BTW, lots of internet sites talk about why cables cannot make a different.
So do you agree that cables cannot make a difference based on that? 🙂
The article I spoke of included jitter measurements, including cd pens making measured differences.
that's why we have so many jitter experts who cannot explain what jitter is, what caused it and why it is worse in certain players than others.
The reason that nobody is explaining to you is that jitter is an elementary concept, and easily researched by yourself on this forum and on the net.
Eric.
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