Meanwhile waiting for John...... the answer as to why CD sound worse than HD downloads is numerous but comes down to one dominating factor - jitter creeping into CD's in many ways. Not the lest of which was the long time standard for recordings.... the Sony PCM1630 recorder's jitter. And, the high speed duplications. As the copy/dup speed increases, so does the jitter. (Masters are done 1X- 4X). And HD Mastering is different from commercial CD Mastering.... most noticeably without added compression.
So, yes, it was in eliminating the CD process of record/ copy/ playback and just use HD files is better...... minimal to practically no jitter.
Tip of the iceberg on jitter:
http://www.digido.com/articles-and-demos12/13-bob-katz/15-jitter.html
http://www.soundonsound.com/sos/nov04/articles/qa1104-3.htm
THx-RNMarsh
So, yes, it was in eliminating the CD process of record/ copy/ playback and just use HD files is better...... minimal to practically no jitter.
Tip of the iceberg on jitter:
http://www.digido.com/articles-and-demos12/13-bob-katz/15-jitter.html
http://www.soundonsound.com/sos/nov04/articles/qa1104-3.htm
THx-RNMarsh
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Richard
you have to distinguish between CD-R and CD. There is no such thing as high speed duplication with commercial CDs, they are stamped "just like" old school LPs. The glass master is made and used to create the actual CD and then plated and sealed. Lots of room for things to creep in, but not high speed dupe errors.
Today and for a while now, most material has been delivered to the plant as a DDP package. A data package that includes all the track and cue information in a data package to keep away from the (real) problems you are referring to. Checksums are standard, no data corruption allowed.
Prior to that and on lower cost disc production today still, the CD-R is often used as a pre-master of the final CD, these can also have the problems you are referring to. Here high speed duping can be a negative. Oddly in the last few years, low speed cdr burring has become a source of error relative to high/medium speed burning. As the optical burners have gotten faster and faster, the disc have changed to keep up and now are optimized for high speed burning, yielding often best results at medium burn speeds, but not low speed where they may not even burn at all!
Most discs made in the last several years are made with digital transmission of the data, often over the internet thru secure servers (no leaks please). Its an ever changing world in terms of delivery of audio to the "masses" and for sure hasn't finished changing yet.
Alan
ah, I see you were referencing Bob Katz's excellent article, however it was written in 2007, many things have changed since then.
you have to distinguish between CD-R and CD. There is no such thing as high speed duplication with commercial CDs, they are stamped "just like" old school LPs. The glass master is made and used to create the actual CD and then plated and sealed. Lots of room for things to creep in, but not high speed dupe errors.
Today and for a while now, most material has been delivered to the plant as a DDP package. A data package that includes all the track and cue information in a data package to keep away from the (real) problems you are referring to. Checksums are standard, no data corruption allowed.
Prior to that and on lower cost disc production today still, the CD-R is often used as a pre-master of the final CD, these can also have the problems you are referring to. Here high speed duping can be a negative. Oddly in the last few years, low speed cdr burring has become a source of error relative to high/medium speed burning. As the optical burners have gotten faster and faster, the disc have changed to keep up and now are optimized for high speed burning, yielding often best results at medium burn speeds, but not low speed where they may not even burn at all!
Most discs made in the last several years are made with digital transmission of the data, often over the internet thru secure servers (no leaks please). Its an ever changing world in terms of delivery of audio to the "masses" and for sure hasn't finished changing yet.
Alan
ah, I see you were referencing Bob Katz's excellent article, however it was written in 2007, many things have changed since then.
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Hello Waltzingbear -
When I copy and when I make a dup/copy here at home it is at fast speed and I think most others do it that way also. The Glass is another story but once jitter is recorded it is hard to get it out in playback.
Things are getting better even in attempts to remove recorded jitter. A better source to get a good over view .. and there are many... is The Mastering Engineer's Handbook: The Audio Mastering Handbook. (2007) esp the area on jitter... then follow it up with a forum that is current in HD/SW.
I agree much is changing..... my collection of 1000 CD's over the past couple decades do not benefit from todays best practices and HD or SW.
Never-the-less, from my sources like BenchMark and reading about the comments in forum by those who teach mastering etc etc etc... what I hear as the big improvment is due to reduced jitter and not whether it is 16b or 24b per se, for example. Nor the error correction.... though the DDP is even stronger. the selection of burner and the blank disk that is best for it is a moving target as well.
Now I am inspired to go find the best available professional burner and burn my HD files into a hard disk CD at slow speed. and find the best blanks for it. But, I'll still play them directly from files as the highest playback fidelity I can muster today.
"Things just keep getting better"
THx-RNMarsh
When I copy and when I make a dup/copy here at home it is at fast speed and I think most others do it that way also. The Glass is another story but once jitter is recorded it is hard to get it out in playback.
Things are getting better even in attempts to remove recorded jitter. A better source to get a good over view .. and there are many... is The Mastering Engineer's Handbook: The Audio Mastering Handbook. (2007) esp the area on jitter... then follow it up with a forum that is current in HD/SW.
I agree much is changing..... my collection of 1000 CD's over the past couple decades do not benefit from todays best practices and HD or SW.
Never-the-less, from my sources like BenchMark and reading about the comments in forum by those who teach mastering etc etc etc... what I hear as the big improvment is due to reduced jitter and not whether it is 16b or 24b per se, for example. Nor the error correction.... though the DDP is even stronger. the selection of burner and the blank disk that is best for it is a moving target as well.
Now I am inspired to go find the best available professional burner and burn my HD files into a hard disk CD at slow speed. and find the best blanks for it. But, I'll still play them directly from files as the highest playback fidelity I can muster today.
"Things just keep getting better"
THx-RNMarsh
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You know, I've never heard this "damaged" sound from this dreadful jitter - I've heard plenty of other things causing audible problems, mainly because of inadequate engineering or weaknesses, which when fixed up give me good sound - same old sad jitter will still be there in the disk, but I ain't hearing it - guess I have lousy hearing ...
OK, I'll bite..
What's the best way to null out the 2nd in your opinion?
Small trimpot at the Jfet sources, like you did, or does adjusting one of the load resistors also make sense?
Good question. I just noticed that the dog ate my homework, so I post again.
I was about to suggest a discussion of distortion.
His newer book is on his web site - Mastering Audio.... 3rd Edition.
Mastering Audio Book - Digital Domain: CD Mastering | Mastered for iTunes | Audio Mastering | Blu-Ray Mastering
THx- RNMarsh
T o minimize 2H....... while waiting for John's reply/answer ----->
1. Symmetrical (push-pull et al) topology
2. matched complimentary transistors
3. Trim Re for distortion null
I havent bought a CD in a long time. So, I bought my last CD burner....
Masterlink ML-9600.
TH-RNMarsh
1. Symmetrical (push-pull et al) topology
2. matched complimentary transistors
3. Trim Re for distortion null
I havent bought a CD in a long time. So, I bought my last CD burner....
Masterlink ML-9600.
TH-RNMarsh
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Hi Richard, waltzingbear,
Richard is correct about the high speed copying and how it creates jitter + data errors. It's the medium that was different. The high speed duplication involves DAT tapes. The blank and master are pressed together, and with some heat and RF bias voltage you get what amounts to "print through". Normally a problem to be avoided, and one reason why master open reel tapes are stored tails out.
CDs are indeed created using the old faithful "pressing" procedure. What used to take place inside a clean room now is done inside a machine with its tiny version of a clean room. There you have problems related to the pressing process, added to the silvering process problems. Has anyone seen their hand or scenery through a CD where the silvering wasn't very effective? Just like the light, the laser beam loses a lot of returned signal. That leads to a low, noisy RF eye pattern. The servos also have to work harder. One servo that controls laser diode current will sometimes (depending on chip set) increase the laser current. Not what you want. In the earlier days of CD players, sometimes the laser head assy would be run right to the rear extreme against a mechanical stop. Sometimes the gear teeth on the rack and pinion would be stripped.
The consumer always gets it between the eyes.
-Chris
Richard is correct about the high speed copying and how it creates jitter + data errors. It's the medium that was different. The high speed duplication involves DAT tapes. The blank and master are pressed together, and with some heat and RF bias voltage you get what amounts to "print through". Normally a problem to be avoided, and one reason why master open reel tapes are stored tails out.
CDs are indeed created using the old faithful "pressing" procedure. What used to take place inside a clean room now is done inside a machine with its tiny version of a clean room. There you have problems related to the pressing process, added to the silvering process problems. Has anyone seen their hand or scenery through a CD where the silvering wasn't very effective? Just like the light, the laser beam loses a lot of returned signal. That leads to a low, noisy RF eye pattern. The servos also have to work harder. One servo that controls laser diode current will sometimes (depending on chip set) increase the laser current. Not what you want. In the earlier days of CD players, sometimes the laser head assy would be run right to the rear extreme against a mechanical stop. Sometimes the gear teeth on the rack and pinion would be stripped.
The consumer always gets it between the eyes.
-Chris
Hi Richard,
That Masterlink ML-9600 looks like "semi-pro" to me. The ad copy reads like it is aimed at the home market. What you really need to do is to figure out exactly what transport it has as that determines everything. You may have bought it already, but I would highly recommend that you look around first.
Alesis was known for budget equipment way back in time when I was servicing that market. Since you intend this to be the last CD mastering machine you buy, shouldn't you look around carefully?
I will be honest with you. I have paid zero attention to the MI and recording market over the last 10 years, so I can't possibly advise you as to what is a good machine and what isn't. But I do know that the corporate personality of a company does not generally change, and this one is focused on the semi-pro market. The mechanical build will reflect this. You should be able to have a peek inside before you buy.
-Chris
That Masterlink ML-9600 looks like "semi-pro" to me. The ad copy reads like it is aimed at the home market. What you really need to do is to figure out exactly what transport it has as that determines everything. You may have bought it already, but I would highly recommend that you look around first.
Alesis was known for budget equipment way back in time when I was servicing that market. Since you intend this to be the last CD mastering machine you buy, shouldn't you look around carefully?
I will be honest with you. I have paid zero attention to the MI and recording market over the last 10 years, so I can't possibly advise you as to what is a good machine and what isn't. But I do know that the corporate personality of a company does not generally change, and this one is focused on the semi-pro market. The mechanical build will reflect this. You should be able to have a peek inside before you buy.
-Chris
Hi John,
I have never used a J-Fet as a pass transistor without feedback. What output voltage would you expect to see, and how much would it bounce around with varying current, say your delta is 10 mA?
Other than that, it would have good PSRR and low noise depending on the varying load current.
-Chris
I have never used a J-Fet as a pass transistor without feedback. What output voltage would you expect to see, and how much would it bounce around with varying current, say your delta is 10 mA?
Other than that, it would have good PSRR and low noise depending on the varying load current.
-Chris
> No questions about the low noise regulator?
Yes, lots. But are we finished with the CCS power supply already (given up) ?
For the regulator :
1) Are you not worried about the high-ish Zout of the regulator (= 1/Yfs of JFET) ?
2) Is 0.1µ sufficient as output cap C3 ? How to determine that value ? Is there an optimum, or as large as possible ?
3) What speaks against replacing R1 by a low-noise Zener followed by an R-C before the JFET gate ?
4) No need to use gate stopper after C2 ?
Patrick
Yes, lots. But are we finished with the CCS power supply already (given up) ?
For the regulator :
1) Are you not worried about the high-ish Zout of the regulator (= 1/Yfs of JFET) ?
2) Is 0.1µ sufficient as output cap C3 ? How to determine that value ? Is there an optimum, or as large as possible ?
3) What speaks against replacing R1 by a low-noise Zener followed by an R-C before the JFET gate ?
4) No need to use gate stopper after C2 ?
Patrick
The ML9600 is a different beast than most Alesis prosumer gear. I worked at Alesis from before the ADAT 'till just after the bankruptcy. The ML9600 is basically a pro piece of gear. Kevin Gray has one in his mastering studio.
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