I want to know if the creators made it 14 bits and then marketing department put pressure on them to go 16 bit with the Sony race at that time (this and the actual best sound outcome).
No, the original CD information is encoded as 16 bit. We are talking first generation stuff here. It was probably technical and rushing to market if I had to guess. Maybe this was the best D/A at the time, but the next chips were all 16 bit. Does that tell you something?
I remember some of this from back in the day.
16 bit technology was absolutely cutting edge for domestic use while 14 bit DAC's were much cheaper and easier to produce and Philips already had these up and running. The 4X oversampling Philips used pushed the resolution close to but not quite 16 bit standards and as a bonus allowed very simple filtering after the DAC while the 16 bit system needed the 'brickwall' filters. The Philips players were reputed to sound better though.
All the early Sony players used to 'time share' the DAC meaning it did both left and right channel decoding while Philips with the cheaper 14 bit DAC used one per channel. I remember the fuss of the time sharing and it could (did) lead to a delay in one channel and possible image shift.
In the end Sony won out though and 16 bit was standardised.
Hi Karl,
Yes, exactly. The interleaving of L and R channels in the DAC caused a 90° phase shift at the highest frequencies. I measured it many times back in the day.
The original Philips using oversampling and two DACS did sound better (which is why I bought a Nakamichi OMS-7 - TDA1540). Nakamichi was one of the cutting edge companies with digital reconstruction a was Revox (I have some Studer machines). Shortly later Nakamichi came out with non-Philips DACs, dual and oversampled. They also notched out the transient glitches before others did.
The first brick-wall filters were L-C tuned units. Later we got into active filters, but they all sounded "not good". Upping the sampling frequency allowed much lower slope (order) filters that were less critical for component value (price), fewer sections (price) and of course had nicer phase characteristics that sounded a lot better. So it was cheaper and performed better. I really do not understand what people see in NOS DACs, and I have seen they do not use the proper filter (smooth move guys!!!). You need those high order filters with NOS DACs.
You'd remember the PCM-56 DAC, the first popular one widely used. You could find that in single (one DAC for both channels) and machines that used dual DACs. Later we got into single bit type DACs, but the good multibit ones always sounded better.
Yes, exactly. The interleaving of L and R channels in the DAC caused a 90° phase shift at the highest frequencies. I measured it many times back in the day.
The original Philips using oversampling and two DACS did sound better (which is why I bought a Nakamichi OMS-7 - TDA1540). Nakamichi was one of the cutting edge companies with digital reconstruction a was Revox (I have some Studer machines). Shortly later Nakamichi came out with non-Philips DACs, dual and oversampled. They also notched out the transient glitches before others did.
The first brick-wall filters were L-C tuned units. Later we got into active filters, but they all sounded "not good". Upping the sampling frequency allowed much lower slope (order) filters that were less critical for component value (price), fewer sections (price) and of course had nicer phase characteristics that sounded a lot better. So it was cheaper and performed better. I really do not understand what people see in NOS DACs, and I have seen they do not use the proper filter (smooth move guys!!!). You need those high order filters with NOS DACs.
You'd remember the PCM-56 DAC, the first popular one widely used. You could find that in single (one DAC for both channels) and machines that used dual DACs. Later we got into single bit type DACs, but the good multibit ones always sounded better.
The Sony CDP101 actually had slightly different component values in the left and right analogue stages after the DAC which I think was an acknowledgement of this problem and image shift some could detect. Its not a misprint in the manual, they really are these values in the real player. The brickwall filter is in the blank rectangle.
A very well liked DAC as I remember 🙂
I still have a Bitstream (1 bit DAC) Micromega Stage 2 player that uses two TDA1305T DAC's and that player has always sounded great and it can still hold its own today. Very smooth and detailed... analogy sounding.
This is why Schiit called its DAC Gungnir Multibit DAC (I never heard this brand but someone praise this DAC to me).
PS i feel the 104 deserves a documentary...
PS i feel the 104 deserves a documentary...
Hi Karl,
That component change can't possibly shift the phase enough, and it doesn't have that issue anyway. I would think it affects gain more than phase anyway. That is a dual DAC. The analogue switches appear to be deglitching and maybe there was an issue with each switch (IC512) or PCB payout they are compensating for. The dual DAC receives information, L then R, but it is synchronized and is output in phase. That eliminated the 19 KHz phase shift between channels (but you also had the filter affecting that region too).
Most of the worst offences in D/A conversion were in the analogue stages (or you could hide problems there). By far the best DAC chip I have heard is the PCM 1702 / 1704. My Denon DCD-S10 uses a pair in co-linear, and each is a co-linear DAC. That's four DAC chips in that machine. Low level linearity is no longer an issue when you do what Denon did, expanding on what Burr-Brown did. I don't know if you can beat that DAC today for sound. I did go over the analogue stages in that machine and it sounds even better.
Hi caisson rj,
Okay, do a documentary on the 104.
That component change can't possibly shift the phase enough, and it doesn't have that issue anyway. I would think it affects gain more than phase anyway. That is a dual DAC. The analogue switches appear to be deglitching and maybe there was an issue with each switch (IC512) or PCB payout they are compensating for. The dual DAC receives information, L then R, but it is synchronized and is output in phase. That eliminated the 19 KHz phase shift between channels (but you also had the filter affecting that region too).
Most of the worst offences in D/A conversion were in the analogue stages (or you could hide problems there). By far the best DAC chip I have heard is the PCM 1702 / 1704. My Denon DCD-S10 uses a pair in co-linear, and each is a co-linear DAC. That's four DAC chips in that machine. Low level linearity is no longer an issue when you do what Denon did, expanding on what Burr-Brown did. I don't know if you can beat that DAC today for sound. I did go over the analogue stages in that machine and it sounds even better.
Hi caisson rj,
Okay, do a documentary on the 104.
Hi Chris, the player is the first generation CDP-101 and the DAC was time shared on those. The DAC is the CX20017 and it is multiplexed between the two channels giving an 11 microsecond difference between channels on playback. This was one of the big criticisms of the player.
I think the multiplexing is why it is called 'dual' in the data sheets but it does alternate between converting the left and then right samples before outputting them. I can find very little technical info on that DAC now.
I think the multiplexing is why it is called 'dual' in the data sheets but it does alternate between converting the left and then right samples before outputting them. I can find very little technical info on that DAC now.
Hi Karl,
Interesting, I didn't know that!
Most stereo DACs did align the outputs with the clock (outputting only on the L or R word clock. I've never seen one that didn't. Good to know for interest's sake I guess. What a weird DAC!
Interesting, I didn't know that!
Most stereo DACs did align the outputs with the clock (outputting only on the L or R word clock. I've never seen one that didn't. Good to know for interest's sake I guess. What a weird DAC!
It was all very much first generation stuff. I've found an internal block diagram of the DAC but beyond that nothing more. I wish I had kept that first player now... it got traded in against a Denon DCD1500 (the original 1500) which was audibly better. The Sony won out on transport quality though. Typical first gen, built like a tank.
Lol!
I have a Denon DCD-3300 sitting here that's mine. In the original box even.
That diagram .. it should have the R and L outputs timed in sync, not shifted by one cycle. That's what the timing generator and latches do. I'll have to see if there is a phase shift on the next player I look at.
I think the very best transport I have ever seen was the NEC used in the Nakamichi OMS-5 / 7 players, also Alpage and a few other high end machines. It was too expensive to produce, a devil to set up. But it produces the very best eye patterns I have ever seen. Generally the Sony transports are better than the Philips ones. Many will argue. Then on top of that, the Sony is repairable.
I have a Denon DCD-3300 sitting here that's mine. In the original box even.
That diagram .. it should have the R and L outputs timed in sync, not shifted by one cycle. That's what the timing generator and latches do. I'll have to see if there is a phase shift on the next player I look at.
I think the very best transport I have ever seen was the NEC used in the Nakamichi OMS-5 / 7 players, also Alpage and a few other high end machines. It was too expensive to produce, a devil to set up. But it produces the very best eye patterns I have ever seen. Generally the Sony transports are better than the Philips ones. Many will argue. Then on top of that, the Sony is repairable.
The CD 104 transport when opening really feels like an ATM machine, not like the crappy late 90s cd players in the mainstream. The closing sound is also very BMW from 90s i would say...
Wow this thread has been running for 20 years.
I'm just trying to sort out a problem in a CD104 by swapping pieces with a functioning CD104. I changed the Preamp PCB and it works but the sound did not seem to be as sharp. Does anyone have a diagram of this board? my folder shows a basic diagram.
Thanks
I'm just trying to sort out a problem in a CD104 by swapping pieces with a functioning CD104. I changed the Preamp PCB and it works but the sound did not seem to be as sharp. Does anyone have a diagram of this board? my folder shows a basic diagram.
Thanks
I guess you are refering to the laser preamp. Search for the CDM1 service manual, pay attention there are several different versions out there (Most of my players had the "G" revision).
Hi A3XT1,
Do not do that.
Laser diodes are static sensitive, so by unplugging the preamp PCB (with laser current control) you can blow the laser diode easily. Additionally there are alignment trimmers on some PCBs, like the preamp on the head. They will not necessarily work with a different head and mech.
I was trained at Philips and other manufacturers back in the beginning. If you don't have the proper equipment and training, get that machine to a trained tech, because if you continue no one will be able to fix maybe both machines.
Why do people think this is easy? No equipment or training required? Blows me away.
Do not do that.
Laser diodes are static sensitive, so by unplugging the preamp PCB (with laser current control) you can blow the laser diode easily. Additionally there are alignment trimmers on some PCBs, like the preamp on the head. They will not necessarily work with a different head and mech.
I was trained at Philips and other manufacturers back in the beginning. If you don't have the proper equipment and training, get that machine to a trained tech, because if you continue no one will be able to fix maybe both machines.
Why do people think this is easy? No equipment or training required? Blows me away.
OOpps I swapped absolutely every single piece untill I located the the bad part. I do have a some equipment for testing but its economics, switching pieces on a CD104 is easy and they are not that expensive relative to the cost of sending them off to be fixed. A CD202 bottom board is a diffeent matter but after a whole load of testing sometimes it saves time just to swapped the boards around.
So am I right in thinking that how the laser preamp board is set up can have an impact on sound? The manual for this board only shows connections, do you have any knowledge about this board? thanks.
PS I learnt how to fix the tray motor on the CD104 and fixed the stop switch at the same time, a real voyage of discovery.
Sticking motor, glue a thin strip of sand paper to a very small allen key and sand off the magnet high point its that simple.
So am I right in thinking that how the laser preamp board is set up can have an impact on sound? The manual for this board only shows connections, do you have any knowledge about this board? thanks.
PS I learnt how to fix the tray motor on the CD104 and fixed the stop switch at the same time, a real voyage of discovery.
Sticking motor, glue a thin strip of sand paper to a very small allen key and sand off the magnet high point its that simple.
"Why do people think this is easy? No equipment or training required? Blows me away."
Very interesting statement.
Very interesting statement.
Hi A3XT1,
Yes, the alignment can have a dramatic effect on sound quality.
Look, DIY is fine, service is totally different. Fixing our own stuff without training or equipment ('cause it's cheaper) leads to things that are not in fact fixed. They may work, but most often not well. Enough DIY repaired equipment hits the open market and good techs like me lose time and money fixing other people's mistakes. If you destroy equipment so no one else can run into it when you're done, okay. But then it is a shame repairable equipment hits the garbage. At the very least you rip yourself off because it doesn't work right. Then you compare performance with other brands spreading false information.
Why on earth do you think real service technicians train for decades and buy expensive equipment? Is it so a rank amaeteur can say they are just as good because they made something function? Then, when do you "fix things" for friends and family - or hang out a shingle? Lot's of that going on. Customers are ripped off because the job isn't done properly and has to be redone at much higher cost.
We waste time trying to help folks who don't have the correct equipment and /or training. When we recognise you are in way over your head, are we thanked for the help so far? Nope. I even helped a guy who then decided he was going to fix stuff that was way, far beyond his knowledge and means. He came over and dropped this stuff on me expecting me to fix it right there and left in a huff after I told him I'd have to look at it later and spend a lot more time on it. I wasn't going to charge him and he still got pissed with me.
When you're told you need "X" equipment, it's because you actually do. Servicing stuff the way you did it can severely damage the pieces you're working on - for nothing. And, you don't learn anything. DIY is all about learning something, it isn't about hack and slash to save a couple bucks. It's about making intelligent decisions as to how to proceed.
DIY is actually about building stuff. Whether it's a kit, or a design of your own. Let's get the definitions right for starters.
Yes, the alignment can have a dramatic effect on sound quality.
It's the attitude. Most people think proper electronic service is easy. It isn't really, not to do it properly. It's easy when you have the knowledge, experience and equipment. Then, we did suffer and work for a very long time to learn what we need to know.
"Just because you can, doesn't mean you should" Sound familiar?
Look, DIY is fine, service is totally different. Fixing our own stuff without training or equipment ('cause it's cheaper) leads to things that are not in fact fixed. They may work, but most often not well. Enough DIY repaired equipment hits the open market and good techs like me lose time and money fixing other people's mistakes. If you destroy equipment so no one else can run into it when you're done, okay. But then it is a shame repairable equipment hits the garbage. At the very least you rip yourself off because it doesn't work right. Then you compare performance with other brands spreading false information.
Why on earth do you think real service technicians train for decades and buy expensive equipment? Is it so a rank amaeteur can say they are just as good because they made something function? Then, when do you "fix things" for friends and family - or hang out a shingle? Lot's of that going on. Customers are ripped off because the job isn't done properly and has to be redone at much higher cost.
We waste time trying to help folks who don't have the correct equipment and /or training. When we recognise you are in way over your head, are we thanked for the help so far? Nope. I even helped a guy who then decided he was going to fix stuff that was way, far beyond his knowledge and means. He came over and dropped this stuff on me expecting me to fix it right there and left in a huff after I told him I'd have to look at it later and spend a lot more time on it. I wasn't going to charge him and he still got pissed with me.
When you're told you need "X" equipment, it's because you actually do. Servicing stuff the way you did it can severely damage the pieces you're working on - for nothing. And, you don't learn anything. DIY is all about learning something, it isn't about hack and slash to save a couple bucks. It's about making intelligent decisions as to how to proceed.
DIY is actually about building stuff. Whether it's a kit, or a design of your own. Let's get the definitions right for starters.
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