So for my first post here on diyAudio, I asked about the SAA7220 being removed from my new to me 965BX; I know this player is not a super-duper, but if I could make it play happier in my system I think it would improve on the Pioneer 609 CDR box I currently use (!)
When it arrived, the ball bearing holder bit in the floating clamp had actually broken out, and was jamming the whole thing - so I've reglued that in place, and after discovering that it should actually have a ball-bearing in it, managed to find it on the carpet about a foot away from where I dismantled it - so that went back in as well.
I've managed to make the tray go in and out better (put the rubber belt in very hot water for a few minutes, and cleaned it well); mended the open/cls button by super-gluing three bits of small shrinkwrap to act as hinges, which work really well; one of the clamp springs had stretched, so I cut a bit off, and reformed the loop and started the process of fitting a figure 8 mains socket rather than sticking with a flying lead.
But I have one very important problem yet to solve, and some advice would be gratefully received. The damn thing will play all the tracks from the inside 3/4 I guess of any CD I throw at it, but then the last few tracks will drive it bananas, skipping like crazy. I've cleaned the lens a bit, I've tried putting extra pressure on the clamp, I've removed and refitted the mechanism, but none of that seems to make any difference.
I realise that there probably isn't an obvious answer, but some thoughts on what to try would be great - other than the "buy a new mech / player" reply !!
When it arrived, the ball bearing holder bit in the floating clamp had actually broken out, and was jamming the whole thing - so I've reglued that in place, and after discovering that it should actually have a ball-bearing in it, managed to find it on the carpet about a foot away from where I dismantled it - so that went back in as well.
I've managed to make the tray go in and out better (put the rubber belt in very hot water for a few minutes, and cleaned it well); mended the open/cls button by super-gluing three bits of small shrinkwrap to act as hinges, which work really well; one of the clamp springs had stretched, so I cut a bit off, and reformed the loop and started the process of fitting a figure 8 mains socket rather than sticking with a flying lead.
But I have one very important problem yet to solve, and some advice would be gratefully received. The damn thing will play all the tracks from the inside 3/4 I guess of any CD I throw at it, but then the last few tracks will drive it bananas, skipping like crazy. I've cleaned the lens a bit, I've tried putting extra pressure on the clamp, I've removed and refitted the mechanism, but none of that seems to make any difference.
I realise that there probably isn't an obvious answer, but some thoughts on what to try would be great - other than the "buy a new mech / player" reply !!
Look at the spinning disc edge on. There should zero runout of the disc i.e it should not show any up or down movement at the edge. Runout is progressively worse the further from the centre you get.
Beyond that you need to use a scope and look at the signal off the disc to get some clues. Some general info on CD player servicing here.
https://www.diyaudio.com/community/threads/sony-cdp790-and-kss240-restoration-project.226288/
Can I ask, politely, if the CD4/19 mech is a fussy thing with regard to cd scratches and scuffs ? It appears that my issues are now just related to skipping when it finds these, a perfect cd plays perfectly !!
A great deal depends on the alignment. In addition what Mooly says just adds more difficulty and you may have issues from several sources making it more difficult to deal with certain defects.
Scratches running radially should be no problem unless they are wide. A scratch on an arc the same way the CD is read will be difficult or impossible for any machine to track. In addition, vibration in teh spindle motor bearing or a bad winding will also make tracking difficult.
The Philips system (single beam) works very well for some defects, and not as well as the normal method (three beam). They are normally all pretty good but when defects get really bad each system has its advantages.
-Chris
Scratches running radially should be no problem unless they are wide. A scratch on an arc the same way the CD is read will be difficult or impossible for any machine to track. In addition, vibration in teh spindle motor bearing or a bad winding will also make tracking difficult.
The Philips system (single beam) works very well for some defects, and not as well as the normal method (three beam). They are normally all pretty good but when defects get really bad each system has its advantages.
-Chris
Hard to answer that without seeing what the actual obstacle course (the scratched disc) is actually like.
It should cope with all the 'standard' defects:
https://www.diyaudio.com/community/threads/test-cd-for-cd-player-adjustment.67783/post-1415445
https://www.dutchaudioclassics.nl/Philips_cdm4_cd_mechanism/
It should cope with all the 'standard' defects:
https://www.diyaudio.com/community/threads/test-cd-for-cd-player-adjustment.67783/post-1415445
https://www.dutchaudioclassics.nl/Philips_cdm4_cd_mechanism/
Bit of an update FYI - still skips, but the workaround is to exact copy the CDs involved (!).
Removed the 7220 chip today - can't quite believe you can literally just desolder it and leave empty pin-holes, but you can. And it definitely makes a difference, in a good/great way.
Trouble is, I can't quite get past the idea of leaving CD behind, and streaming the ripped music from my NAS, and the thought of having hundreds more CDs to store drives my wife mad, and not in a good way !!
Removed the 7220 chip today - can't quite believe you can literally just desolder it and leave empty pin-holes, but you can. And it definitely makes a difference, in a good/great way.
Trouble is, I can't quite get past the idea of leaving CD behind, and streaming the ripped music from my NAS, and the thought of having hundreds more CDs to store drives my wife mad, and not in a good way !!
🙂 Not quite following you on that. I know what Exact Audio Copy is, I've used it a couple of times myself years ago... why more CD's to store though? Are you burning the new data to a CDR/RW?
That's always an interesting one. If you like how it all sounds then that's great.
Reminded of something I tried years ago:
https://www.diyaudio.com/community/...ations-to-a-budget-player.274521/post-4333881
That's always an interesting one. If you like how it all sounds then that's great.
Reminded of something I tried years ago:
https://www.diyaudio.com/community/...ations-to-a-budget-player.274521/post-4333881
I don't know about you, but my CD player sounds better than my Bluesound Node 2i - and that thing is no slouch! So I still listen to and buy CD's, and have streamers on every system (three good ones) as well. Now every streamer is connected via Ethernet (sounds better) or maybe WiFI, but I do not use BlueTooth at all.
Streamers have their place, as do CD Players. I even have turntables (different again). If all your equipment is really good, the media still has high value. Then there are times the streaming service drives me totally nuts. I just grab a CD and move that to areas where I am when I've had enough of issues.
The Philips chip set is not my favorite, and I would love to replace it in my old Nakamichi OMS-7. Some day. Therefore I am not too surprised to hear what you said. However the digital filter is necessary, but with earlier equipment the slopes were wicked sharp. That creates issues. Understand that any sharp filter may have issues, but they really are needed. Do you think for a second that any manufacturer would install an expensive part (and they really were!) if it was not required?
The fix for that problem was much higher sampling rates so that he filter slope could be reduced. That is why they went that route. The problem is that 44.1 KHz does get amplified by the other parts of your system. 96 KHz has reduced amplitude, and 192 KHz is even better as it is normally outside the passband of your amplifier. But the filters, be they analogue or digital or both (usually) are certainly required. You can't always go by ear, and what "sounds better" may not be better for your system.
-Chris
Streamers have their place, as do CD Players. I even have turntables (different again). If all your equipment is really good, the media still has high value. Then there are times the streaming service drives me totally nuts. I just grab a CD and move that to areas where I am when I've had enough of issues.
The Philips chip set is not my favorite, and I would love to replace it in my old Nakamichi OMS-7. Some day. Therefore I am not too surprised to hear what you said. However the digital filter is necessary, but with earlier equipment the slopes were wicked sharp. That creates issues. Understand that any sharp filter may have issues, but they really are needed. Do you think for a second that any manufacturer would install an expensive part (and they really were!) if it was not required?
The fix for that problem was much higher sampling rates so that he filter slope could be reduced. That is why they went that route. The problem is that 44.1 KHz does get amplified by the other parts of your system. 96 KHz has reduced amplitude, and 192 KHz is even better as it is normally outside the passband of your amplifier. But the filters, be they analogue or digital or both (usually) are certainly required. You can't always go by ear, and what "sounds better" may not be better for your system.
-Chris
From a thread somewhere on here, I was under the impression that the 7220 was only used in the Digital Out circuit, which I'm not using since the transport side of the player isn't reliable enough anyway. The extra CDs to be stored are because it sounds so good to me now (at the moment - I haven't listened to my analogue source for about 10 years!) that I'm going to be scouring the charity shops !!
Hi Jeff,
That might be the case with your machine, but in mine it is there and I have no digital output. I have not examined the schematic for your CD player. Really, the digital filter - if for the digital output cannot possibly affect the sound quality! If it were me, I would reinstall it. If it does in fact do something, it will be an improvement but expectation bias from what you have read will make you think otherwise. One thing I can tell you is that CD players do not all sound the same, and really good ones sould much better. I have improved all of mine, but they were all expensive, great sounding machines to begin with. These days they are all Denon except for the Nakamichi OMS-7.
The same holds for analogue sources. I use a Revox B-261 tuner, and a Thorens TD-126 MKII with an Ortofon 540 MKII cartridge. Nothing here is inexpensive, but nothing is stupid priced either. I also have a TD-125 MKII, another great table that once you compare it to others, you will understand. Original arms by the way. The original Thorens arm is much better than anyone gives them credit for, and they are much better than many aftermarket arms. Of course that truth is inconvenient to folks in the audio sales "profession". I have installed original arms on these tables and their owners were very grateful!
Phono cables. If they put on low capacitance cables, you have to add the missing capacitance somewhere. The cartridge resonates with that to extend HF response and make it flat. Each cartridge has a capacitance it is designed to work into. Most preamps have similar input capacitance and that forms part of that capacitive load. For the best system, you measure the cables and the preamp input, compare to the cartridge specs and add or subtract as needed.
What this means is that you want a good turntable, with original arm and cables. It doesn't make sense to install an expensive after market arm that is actually good, on something like a Technics SL1200(mark whatever)! The Technics is a good table for it's class, but a Thorens or Linn (expensive and no better) is an entirely different class of table. Technics is better than the Sony's and Pioneers of the world and there are others as good as the technics or a little better.
-Chris
That might be the case with your machine, but in mine it is there and I have no digital output. I have not examined the schematic for your CD player. Really, the digital filter - if for the digital output cannot possibly affect the sound quality! If it were me, I would reinstall it. If it does in fact do something, it will be an improvement but expectation bias from what you have read will make you think otherwise. One thing I can tell you is that CD players do not all sound the same, and really good ones sould much better. I have improved all of mine, but they were all expensive, great sounding machines to begin with. These days they are all Denon except for the Nakamichi OMS-7.
The same holds for analogue sources. I use a Revox B-261 tuner, and a Thorens TD-126 MKII with an Ortofon 540 MKII cartridge. Nothing here is inexpensive, but nothing is stupid priced either. I also have a TD-125 MKII, another great table that once you compare it to others, you will understand. Original arms by the way. The original Thorens arm is much better than anyone gives them credit for, and they are much better than many aftermarket arms. Of course that truth is inconvenient to folks in the audio sales "profession". I have installed original arms on these tables and their owners were very grateful!
Phono cables. If they put on low capacitance cables, you have to add the missing capacitance somewhere. The cartridge resonates with that to extend HF response and make it flat. Each cartridge has a capacitance it is designed to work into. Most preamps have similar input capacitance and that forms part of that capacitive load. For the best system, you measure the cables and the preamp input, compare to the cartridge specs and add or subtract as needed.
What this means is that you want a good turntable, with original arm and cables. It doesn't make sense to install an expensive after market arm that is actually good, on something like a Technics SL1200(mark whatever)! The Technics is a good table for it's class, but a Thorens or Linn (expensive and no better) is an entirely different class of table. Technics is better than the Sony's and Pioneers of the world and there are others as good as the technics or a little better.
-Chris
What the "experts" said was that this chip has a nasty habit of inducing noise into the power supply line - which then gets propagated through anything else that uses that same power. I profess I don't understand it, but my ears tell me that some of the nastier side of CD seems to have gone - Norah Jones always had a harsh edge to her voice, which although is still there to some extent, could now just be the way she sings, and isn't hard on the ears like it was. As for the analogue - I like to think that what I own proves to some extent that I do have some capabilities in hifi land - a Pink Triangle PT Too, with an SME 309 arm and a Lyra Clavis MC cartridge (into a Project Tube Box). The fact that I then run all this into a denon AV receiver, rather than my original Velleman 4040 valve amp is to be ignored !!!
Hi Jeff,
Not true.
However, those bypass capacitors have a habit of going bad. If they are bad you will find all kinds of noise on the power supply.
But whatever makes you happy. You have to understand, no manufacturer will ever add an expensive part that negatively impacts sound quality. That simply makes no sense!
-Chris
Not true.
However, those bypass capacitors have a habit of going bad. If they are bad you will find all kinds of noise on the power supply.
But whatever makes you happy. You have to understand, no manufacturer will ever add an expensive part that negatively impacts sound quality. That simply makes no sense!
-Chris
My current plan is to solder in some 8 pin sockets for the opamps, so I'll install a 40 pin (or whatever number!) for the filter at the same time - and then do some listening tests with and without - and I'll write up my conclusion. Any thoughts about wether turned pin or flat leg sockets work best ??!!
No socket!!!!
A socket adds capacitance between the pins. If you want to run a specific test for the digital filter you can use a socket for that. Augat would be a reasonable choice. The cheap sockets will cause more problems and you do not need that. Also, Ebay and Chinese sockets are terrible! I use sockets for various purposes, and even the good looking off-brands are nothing but trouble. So buy from Digikey, Mouser or whoever is similar. The circular, machined sockets are the best.
For the audio section, do not install sockets. If you're going to replace the op amps, almost any of the newer good ones are so much better there is no difference between them. However, fast op amps can oscillate. You want a slower, low distortion op amp, getting a speed demon will actually reduce performance. By slower, I mean less than 20 V/usec - and that is smoking fast for audio. Also, Fet type op amps and bipolar types each have characteristics where they may not perform as well in some circuits. There is no "best", you have to select according to the circuit and requirements. Hmmm, sounds like engineering more than "op amp rolling" ( a stupid term if you ask me).
-Chris
A socket adds capacitance between the pins. If you want to run a specific test for the digital filter you can use a socket for that. Augat would be a reasonable choice. The cheap sockets will cause more problems and you do not need that. Also, Ebay and Chinese sockets are terrible! I use sockets for various purposes, and even the good looking off-brands are nothing but trouble. So buy from Digikey, Mouser or whoever is similar. The circular, machined sockets are the best.
For the audio section, do not install sockets. If you're going to replace the op amps, almost any of the newer good ones are so much better there is no difference between them. However, fast op amps can oscillate. You want a slower, low distortion op amp, getting a speed demon will actually reduce performance. By slower, I mean less than 20 V/usec - and that is smoking fast for audio. Also, Fet type op amps and bipolar types each have characteristics where they may not perform as well in some circuits. There is no "best", you have to select according to the circuit and requirements. Hmmm, sounds like engineering more than "op amp rolling" ( a stupid term if you ask me).
-Chris
Ok, so I need to moot my ideas based on what you've just said, and before.
Sockets, even to my mind, are inducing an extra join even if nothing else, so can't be a "good" thing in any form - but I find it interesting that you chose the round pin version - I would have thought that the contact between a flat chip leg, and a round hole, is minimal - whereas into a flat hole that grips the leg front and back would be maximised - am I getting that wrong somehow ?
and my other question was about the manufacturer putting stuff in for no reason - isn't the digital filter necessary for the digital out signal (I have no idea how the electronics work!) so if they want a digital out socket for sales reasons, then they have to put the chip in. When in, they then have to either accept what a cheap install does, or spend even more money sorting out any issues it creates - which might be the point at whoch they can't spend any extra money ?
Just to emphasise, I'm not wanting to argue, it's just an interesting discussion !!
Sockets, even to my mind, are inducing an extra join even if nothing else, so can't be a "good" thing in any form - but I find it interesting that you chose the round pin version - I would have thought that the contact between a flat chip leg, and a round hole, is minimal - whereas into a flat hole that grips the leg front and back would be maximised - am I getting that wrong somehow ?
and my other question was about the manufacturer putting stuff in for no reason - isn't the digital filter necessary for the digital out signal (I have no idea how the electronics work!) so if they want a digital out socket for sales reasons, then they have to put the chip in. When in, they then have to either accept what a cheap install does, or spend even more money sorting out any issues it creates - which might be the point at whoch they can't spend any extra money ?
Just to emphasise, I'm not wanting to argue, it's just an interesting discussion !!
Hi Jeff,
No problems. I'm not arguing.
There is higher contact pressure between the fingers of the round machined socket than the flat surface types. That ensures a gas-tight seal, higher contact pressure as well in the contact area. They have reduced mating cycles, but that is fine. These don't have the same "extra joint" issues a flat contact area has.
I don't know how it was implemented in your machine, but a digital filter up-samples the data allowing a reduced order filter on the analogue side (those must exist!!). This occurs before the D/A converters in the digital data path, there may be a fall back path - I don't know on yours. Later chip sets encorporated better DSP and filter chips, and they do sound a lot better. There may be other functions inside a digital filter chip, depends on the manufacturer.
Without examining your machine I couldn't begin to give you specifics, and it is also old so there may be other issues as well. Let's just say that non-technical "experts" do not have the actual knowledge or real experience required to comment. Nor do they have the equipment required to actually know anything with any certainty. People have thought equipment with a few percent THD sounded great. That is until it was fixed and they heard the repaired product. People are awful test instruments. I have successfully rebuilt car engines, but no way would I ever advise anyone in a forum or otherwise on how to do it today. Those results are easier to see than what you are doing.
No problems. I'm not arguing.
There is higher contact pressure between the fingers of the round machined socket than the flat surface types. That ensures a gas-tight seal, higher contact pressure as well in the contact area. They have reduced mating cycles, but that is fine. These don't have the same "extra joint" issues a flat contact area has.
I don't know how it was implemented in your machine, but a digital filter up-samples the data allowing a reduced order filter on the analogue side (those must exist!!). This occurs before the D/A converters in the digital data path, there may be a fall back path - I don't know on yours. Later chip sets encorporated better DSP and filter chips, and they do sound a lot better. There may be other functions inside a digital filter chip, depends on the manufacturer.
Without examining your machine I couldn't begin to give you specifics, and it is also old so there may be other issues as well. Let's just say that non-technical "experts" do not have the actual knowledge or real experience required to comment. Nor do they have the equipment required to actually know anything with any certainty. People have thought equipment with a few percent THD sounded great. That is until it was fixed and they heard the repaired product. People are awful test instruments. I have successfully rebuilt car engines, but no way would I ever advise anyone in a forum or otherwise on how to do it today. Those results are easier to see than what you are doing.