Re: Re: Re: Re: Time for a sanity check!
stop putin' metal discs in them , ya metal man
Magura said:
Yuo seem to have gone through a lot of cd mech's, which of the mech's would you expect is most durable?
I know this question may seem strange, but I'm sick of buying new CD players every 3rd year.
Magura
stop putin' metal discs in them , ya metal man
Hi georgehifi,
Your listening tests have far too many variables acting to be able to say anything with real certainty. That is why I tried to point your mind in the direction of the physics of the situation. You don't even know enough to quantify and control these variables.
Now, just so you know, I was authorized warranty for Tascam products (and many others). I actually tuned them up an undid damage that some Canadian tweekers did. I am more than technically familiar with most of the CD mechs you use as an example. You are quite obviously not.
I have rebuilt many units used by radio stations and the worst - restaurants. Restaurants will typically wear a normal CD player out in 6 to 9 months. (they think they are under warranty, professional use warranty is 90 days).
Now an experiment. Another physics lesson for you. Take a rubber record mat and spin it. You can use any floppy disc (no pun intended) you want. Spin that thing and you will see that it is no longer floppy at all. The act of spinning the disc makes it follow it's mean center and resist a change in motion. Amazing stuff, the laws of physics are consistent. Cool!
George, monitor the error correction flags and the RF waveform. Mess around with clocks and you will witness that the RF waveform does not change. Your error flag activity won't either, although they are not repeatable. You will see a high random amount of variability. This is your transport and the thing that gives you your analog RF signal that you will decode your information from. If your error flags are the same, then so is the sound. The rest is in your head and has more to do with it's nameplate than anything else.
So, to recap. The indicator of quality is the eye pattern and number of error flags. Period. End of story. No magic here. If you can hear a difference, you would see a large difference in the number of error flags. So go figure out where the C1 and C2 flags are and go listen. If you bang on the player you can watch the flags increase. Correlate that to your listening tests.
Hi Guido,
Please look at what I have posted and let me know where you think I may have erred.
Hi Magura,
With high run time, you may need to stick the CD's on hard drives. The units with non-standard heavy motors and no heavy clamper might be the best best. I would favour the inexpensive transports (like the old Tascam CD-301). These parts are inexpensively replaced and you end up with essentially a new unit. So you can put them on a service cycle that may be from 6 months to 2 years depending on your use. Service is cheaper and you don't have to relearn a new unit. The devil you know ....
-Chris
The main problem that you have is a complete lack of knowledge of how these things work. The ultimate tweeker!
Your listening tests have far too many variables acting to be able to say anything with real certainty. That is why I tried to point your mind in the direction of the physics of the situation. You don't even know enough to quantify and control these variables.
Now, just so you know, I was authorized warranty for Tascam products (and many others). I actually tuned them up an undid damage that some Canadian tweekers did. I am more than technically familiar with most of the CD mechs you use as an example. You are quite obviously not.
Oh please George! You haven't got a real clue at all here.
I have rebuilt many units used by radio stations and the worst - restaurants. Restaurants will typically wear a normal CD player out in 6 to 9 months. (they think they are under warranty, professional use warranty is 90 days).
Now an experiment. Another physics lesson for you. Take a rubber record mat and spin it. You can use any floppy disc (no pun intended) you want. Spin that thing and you will see that it is no longer floppy at all. The act of spinning the disc makes it follow it's mean center and resist a change in motion. Amazing stuff, the laws of physics are consistent. Cool!
George, monitor the error correction flags and the RF waveform. Mess around with clocks and you will witness that the RF waveform does not change. Your error flag activity won't either, although they are not repeatable. You will see a high random amount of variability. This is your transport and the thing that gives you your analog RF signal that you will decode your information from. If your error flags are the same, then so is the sound. The rest is in your head and has more to do with it's nameplate than anything else.
So, to recap. The indicator of quality is the eye pattern and number of error flags. Period. End of story. No magic here. If you can hear a difference, you would see a large difference in the number of error flags. So go figure out where the C1 and C2 flags are and go listen. If you bang on the player you can watch the flags increase. Correlate that to your listening tests.
Hi Guido,
Please look at what I have posted and let me know where you think I may have erred.
Hi Magura,
With high run time, you may need to stick the CD's on hard drives. The units with non-standard heavy motors and no heavy clamper might be the best best. I would favour the inexpensive transports (like the old Tascam CD-301). These parts are inexpensively replaced and you end up with essentially a new unit. So you can put them on a service cycle that may be from 6 months to 2 years depending on your use. Service is cheaper and you don't have to relearn a new unit. The devil you know ....
-Chris
georgehifi said:
That is not the way it is in real life. The pioneers (note this is written in pluralis) went south much earlier. None of them lasted more than 1.5 year, one didn't make it to see it's 1 year birthday
I have had old phillips that survived this treatment for +3 years. Average lifespan has though decreased, hence my previous question.
I will take a look and see if I can find a Tascam around here...never seen one before though....but it seems to be the solution I'm looking for.
Magura
Hi Magura,
These Sony transports have a huge advantage. They are inexpensively repaired. If you do this, you can probably get better performance out of the unit. All they need is a little care setting them up.
-Chris
I intended to have you pick up anything with a standard Sony transport with the features you need.
These Sony transports have a huge advantage. They are inexpensively repaired. If you do this, you can probably get better performance out of the unit. All they need is a little care setting them up.
-Chris
Hello Chris,
while you're here and willing to answer a few questions on drive longevity, I'll just air a few of my observations (prejudices)
Seriously, as a long time tech, you have a perspective on this few would match, so Im really interested in your dismissal of the Philips swing arm mechs.
Putting aside the political problem, of no support, and the obvious change in policy with the CDM12, I would offer the observation that the CDM0 and CDM1 are mechanically very sound, and some would say 'over engineered'.
Certainly on the face of it, they combine a simple operational principle (single beam) with an elegant mechanism with two moving parts (motor and arm). Both appear to offer long time serviceability, without maintenance.
Those two series CDM0 and CDM1 are much sturdier than the later swing arms - cdm2 to 4 (and that horror linear thing).
I will grant you that the increased mass of the arm seems to translate to a docile servo software, with a track access time measurable on a sundial
However, this is my observation of the technology, YOU have the practice in the field.
I and others (Magura?) would like to know why this apparently promising technology turns down the corner of your mouth.
It was the mech of choice for Revox/Studer, and they are famous fly-by-nights....
Anecdotally, I have collected over 10 CDM0/1 players (for reasons that are too boring to discuss), and all the drives work perfectly after 20 to 25 years of abuse....
If you have the time please post a reply on your experience servicing that first generation of drives ...(They often use your DAC of choice).
Regards
Philippe
while you're here and willing to answer a few questions on drive longevity, I'll just air a few of my observations (prejudices)
Seriously, as a long time tech, you have a perspective on this few would match, so Im really interested in your dismissal of the Philips swing arm mechs.
Putting aside the political problem, of no support, and the obvious change in policy with the CDM12, I would offer the observation that the CDM0 and CDM1 are mechanically very sound, and some would say 'over engineered'.
Certainly on the face of it, they combine a simple operational principle (single beam) with an elegant mechanism with two moving parts (motor and arm). Both appear to offer long time serviceability, without maintenance.
Those two series CDM0 and CDM1 are much sturdier than the later swing arms - cdm2 to 4 (and that horror linear thing).
I will grant you that the increased mass of the arm seems to translate to a docile servo software, with a track access time measurable on a sundial
However, this is my observation of the technology, YOU have the practice in the field.
I and others (Magura?) would like to know why this apparently promising technology turns down the corner of your mouth.
It was the mech of choice for Revox/Studer, and they are famous fly-by-nights....
Anecdotally, I have collected over 10 CDM0/1 players (for reasons that are too boring to discuss), and all the drives work perfectly after 20 to 25 years of abuse....
If you have the time please post a reply on your experience servicing that first generation of drives ...(They often use your DAC of choice).
Regards
Philippe
Hi rfbrw,
Hi Philippe,
Well, the swing arm is very complicated to set up. The geometrys are very involved and interactive. Worse than a tone arm. That and the fact that they are not really field serviceable. That is a rip off for the customer.
Now, I am not afraid of tough mechanisms. The OMS 5/7 uses a single spot system. The head is completely free for adjustment in all planes. I actually enjoy setting these up because the performance is so high once you are done. Beautiful NEC head. Model optics and expensive as sin. My cost was well over $500 after they dropped in price. The setup takes about 5 hours. However, they were serviceable. I value this above almost anything.
One thing about those first few transports. Some of the Revox ones would sag (the lens). New transport time. These were about $700 I think.
However, I am very happy when I repair one and the head is fine. McIntosh used them also. Now, the real rip off is any board made by Philips. They use the cheapest parts they can lay their hands on it seems. No grease on regulators either.
Politically, I dislike Philips. I won't hide that fact, and I think I have just cause. They have created much grief for the average customer. They do not understand that Philips has always made throwaway products. I have no respect for that.
-Chris
I am very fond of the PCM1702. I'd like to try and play with the PCM1704 as well. Of course, once I start there are probably others.
Hi Philippe,
Well, the swing arm is very complicated to set up. The geometrys are very involved and interactive. Worse than a tone arm. That and the fact that they are not really field serviceable. That is a rip off for the customer.
Now, I am not afraid of tough mechanisms. The OMS 5/7 uses a single spot system. The head is completely free for adjustment in all planes. I actually enjoy setting these up because the performance is so high once you are done. Beautiful NEC head. Model optics and expensive as sin. My cost was well over $500 after they dropped in price. The setup takes about 5 hours. However, they were serviceable. I value this above almost anything.
One thing about those first few transports. Some of the Revox ones would sag (the lens). New transport time. These were about $700 I think.
However, I am very happy when I repair one and the head is fine. McIntosh used them also. Now, the real rip off is any board made by Philips. They use the cheapest parts they can lay their hands on it seems. No grease on regulators either.
Politically, I dislike Philips. I won't hide that fact, and I think I have just cause. They have created much grief for the average customer. They do not understand that Philips has always made throwaway products. I have no respect for that.
-Chris
anatech said:
Chris,
As an audio designer, I am only interested in the jitter at the EFM signal. Many design errors contribute here, apart from pit jitter that is in the disc.
Crosstalk towards the (tiny) diode currents running over cm's of flex cable is one of those problems, easilly solved by putting the preamp on the pickup. Yes, if everyone does their job properly, but real world is different, and I know that as I have been involved in EMC design within Philips for years: Cleaning up electronic dirt caused by other engineers.
The lower the platter weight, the less the wear on the bearings and motors, and the lower the servo currents (yes, these also affect the jitter perfomance as laying out PCBs should be done by engineers, not by layout people)
best
-
Guido
late to the question.
two transports that I have always thought pretty highly of are the Pioneer "stable platter" (I own an old PD54), and the Technics/Panasonic unit as used on the old Technics slp8 cd player of 20ish years ago.
I am no tech, but the Technics pieces seem to keep going. The Pioneer was chosen due to its inverted laser and the fact that I live in one of the windiest and (and dustiest) parts of the country.
two transports that I have always thought pretty highly of are the Pioneer "stable platter" (I own an old PD54), and the Technics/Panasonic unit as used on the old Technics slp8 cd player of 20ish years ago.
I am no tech, but the Technics pieces seem to keep going. The Pioneer was chosen due to its inverted laser and the fact that I live in one of the windiest and (and dustiest) parts of the country.
Hi Guido,
I agree with everything you've said there. We are on the same page, and even on the same sentence!
Guido, what are your thoughts on the VAM1202 and the RF board made in China?
Hi rfbrw,
Hi Nanook,
-Chris
Edit: Don't worry too much about dust. Cooking oils and smoke are far worse and then it doesn't matter which way is up for the laser.
I agree with everything you've said there. We are on the same page, and even on the same sentence!
Guido, what are your thoughts on the VAM1202 and the RF board made in China?
We aren't talking about a swing arm transport are we? Leave those as they are!
Hi rfbrw,
More probably the DF1700 or something along that line. It's like they were made for each other.
Hi Nanook,
Yes, they do tend to last. They make good linear tracking mechs. I just hate the Mash D/A process.
I hate to cut something up, but those are terrible. A really cheap head with poor glue on the lens. The lenses fall off if they get too warm! Replacement heads are supplied with the diffraction grating misadjusted, and they are a pain to set up. The same disc motor everyone uses with a short shaft, but the added mass off their platter. Those motors get torn up badly. A really cheap and nasty setup. Great advertising though.
-Chris
Edit: Don't worry too much about dust. Cooking oils and smoke are far worse and then it doesn't matter which way is up for the laser.