No new CD transport projects

Thanks leadbelly - pretty much agrees with what I suggested. A bunch of obscure recordings of classical music and token, one off albums (rather than even discographies). Nothing that, even if bought in full (as in I bought everything I just looked at) would constitute a record collection.



Further to that, it also agrees with what I said that the standard for high res audio has never really been ratified. I found a DVD audio and you produced a list of SACDs. Both have been around for around 20 years now and it's clear neither have made an impact with T.Rex only being released two days ago, only 50 years after its original release (and dare I say recording on now ancient analogue tapes?)! HDCD as I said before had a similar fate.



Not that I'm trying to be argumentative or just whinge at you, but hi-res formats are more dead than the CD! They never even got started. If that's all you listen to, then perhaps someone else on the forum can introduce you to music one day. I have some great albums that won't be released on SACD until 2070!
 
Salar said:
For almost a decade I am seeking to build a transport from scratch.
I did measure and digititise the Sony BU-1 into CAD besides the guts.
I am not an engineer and asked many times in this forum to join to do the math needed:
Optical calculations, reverse engineering of the 80´s circuits, designing the coils etc.
No copyright infrightment to be feared, as patents have run out for more than 10 years.
But no one joined so far.
Also the side-project for at least replacing the laser diodes is pending fo almost 18 months now...
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You have all the metal work, much of it precision stuff, and then some kind of control i/f. It is a lot of work. Much easier to buy a spare player or two.
 
Salar said:
For almost a decade I am seeking to build a transport from scratch.
I did measure and digititise the Sony BU-1 into CAD besides the guts.
I am not an engineer and asked many times in this forum to join to do the math needed:
Optical calculations, reverse engineering of the 80´s circuits, designing the coils etc.
No copyright infrightment to be feared, as patents have run out for more than 10 years.
But no one joined so far.
Also the side-project for at least replacing the laser diodes is pending fo almost 18 months now...
Click to expand...



I very much doubt you'll find anyone to engineer a Laser for you.
Why don't you use an existing laser?
The Far East is a good source of copies of already proven Lasers. Yes, some of these are of dubious quality (mostly the Philips ones in my experience). However, I have had some good experiences on the whole with the Sony copies produced.
So, why not start with a Sony KSS-213 for example. The Sony datasheet is readily available on-line so a Mechanism (if you don't want to use the Sony one which many of the Lasers come with ) can be designed easily (for someone with CAD experience and know-how).

'All' that would then be necessary is the RF, Servo processing and DATA manipulation and processing to be designed and implemented into an FPGA (?)
This is way beyond by capabilities but from what I see on here there are many with those skills who I am sure could come up with the design/s necessary. You may already have done this yourself.
It's my lack of capabilities with the 'electronics' side which is why I used an existing Laser and old, tried and tested control and processing electronics.

I for one don't think CD is a dead or dying format. There are just too many about for it to disappear. And it is just so much better sounding, IMO, than anything else that tries to emulate or supercede it.
So if your project idea gets going I think many would be interested. But I would leave trying to engineer a 'new' Laser and use an existing (albeit a copy) design.
 
Percival007, I had seen that but the people don't seem to be very active. If you look at their existing designs they are generations out and the new board looks to be using silicon that isn't yet available(!). However it was their reference design for the CD-80 board that led me to realise that the controller circuitry is all largely standard (they use a Sony KSS3xx can't remember exactly).

If you take a look at On Semiconductor's Search Results LC7861x devices, especially the 5 variant, you'll see it's a single chip solution. It's certainly not dedicated to a brand of mech and no FPGA is involved. The servo drive, focus and RF and all those other things have been integrated from a small chipset to

Looks like the output is even available in the I2S format directly which is ideal for the DIY enthusiast as everyone hates S/PDIF. With a decent output stage and the right cable you could drive that signal for a few metres and improve massively on the S/PDIF options. It appears that the software control is behind an NDA so I have asked for it. I suspect it's a repackaged old chip though so am trying to identify which one.

I would probably steer away from the Sony ones initially as although the Philips ones are not as great as they used to be, they have the benefit of really good datasheets that are uber widely available, they are somewhat of a defacto and they still have the spindle set up for magnetic clamping, really useful for development and testing (have you ever tried to rest a rock on a rotating disc!). Plus that sort of design lends itself better to DIY transporst. With a mech costing less than 20 quid delivered from Cricklewood, reliability probably isn't much of a factor for this sort of thing. Lets try the Sony in a phase 2 as I would be interested in the cross-mech use of a controller. I think that on DIY audio and from the era when it was more practical to repair CD players, it's easier to apply that to the Philips mechs and there is a bigger wealth of knowledge (including as you say, that which says stay away from Philips).

As it happens, the extra info from On Semi has just arrived so I will go and read it!
 
I found this which is quite interesting..........

PRODUCTS | SUOS-Hifi
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The SUOS stuff is rubbish. It is a simple of the shelf Sanyo SF-HD850 / DM3381 mechanism. They tossed the folded metal chassis and replaced it with a cnc-milled chassis and replaced the original plastic turntable with a metal one. Thats all.
Same cheap gear, motors and bearings like before. A Volkswagen Beetle under the bodywork of a Ferrari.
Same diode that will overheat and die earlier because of the plastic housing of the laser-unit and
the heat is not disspated through a die cast housing, common pactice until the early nineties.
This is why especially many players from the eighties still work.

Many do not get the goal of my project:
Longetivety:
That´s why I chose the BU-1 for reverse engeneering, it has brushless motors and no gear at all
Again, patents expired, the design is from 1984
Reparability:
With my concept, the laser diode and photodiodes could be swapped -
no need to toss a whole drive just because the laserdiode died or the photodiodes became noisy

If an FPGA is dead the whole drive is dead. If the design can be as "analog" as the early circuits were,
there is more chance for repairabilty. Get yourself the Service Manuals of a Sony CDP-101 or CDP-103 or Denon DCD-1800,
or Toshiba-XR-Z70 or Philips CD-100 to understand what I mean.
Many what was written here since my last post has already been written before...

Twelveeyedfish, Philips CD-Mech division is out of business since 2007...
These are the ONLY mechs available in 2020 and they are multifuncional,
besides CD they are also for DVD and SACD as DVD and SACD share the same wavelength:

Sanyo SF-HD 850 / DM3381
Hitachi-HOP 1200

Sony does not seem to produce mechs anymore. Those KHM313 are probably counterfeits or produced 3rd party...
 
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Salar, there are some unusual comments in what you have written

- no CD mech uses an FPGA as this would be the most collossally costly (rhymes) way of making a CD mech. They use ASICs (and always have - see your service manuals for CD101 etc) as there is no need for them to be field programmable. These ASICs are a mix of analog and CMOS just like you say. Therefore they cannot be implemented in an FPGA.
- SUOS do use the Sanyo, well sported.
- Designing a CD mech is different to designing a transport. They are two separate engineering exercises. One suits the scale of DIY audio, the other suits optimisation of a tool at the peak of its potential (the 1990s!)
- Longevity - an entire replacement mech is less than 20 quid, a laser about 10 quid. Meh. 2 pints these days.
- I doubt the mechs you quote are the only two currently in production, but the Sony mechs from their own data were assembled from a series of 3rd party parts. These two mechs don't satisfy the products I see on the market now.
- I do gather the Philips units are out of production by Philips, though I suspect the catalog was sold on
- Even if they are not being produced, there are so many Philips mechs still available that I was able to source 300 VAM1202s within 2 minutes of checking (that was never the case for the CDPro2!). That will do for now. People on here know how to work with them. If they are counterfeit, they are still getting 5* buyer reviews which will do.
- A design with a mech available in 2020 is far more practical than with a BU-1* which a quick search produced no available units.

With such strange ideas being circulated it's easy to see why no one has got anywhere with this! With the integration excercise out of the way, there's a lot of room to play and improve PSUs, interconnections and much more. Plus some people's talents are in mechanical design! They've done some great things.

Referring to your first post on this thread, I *am* an engineer and I've done more complex things than this! I just fear I won't get it done before I have to go back to work!
 
The CD / DVD mech is perfect now. They are all bit accurate even the $15 ones for computer. this is why the mechanism project died
if you want to improve sound quality it is the D/A converter and crystal timing that needs work.
 
stocktrader200 said:
The CD / DVD mech is perfect now. They are all bit accurate even the $15 ones for computer. this is why the mechanism project died
if you want to improve sound quality it is the D/A converter and crystal timing that needs work.
Click to expand...

But WHAT CD mech! You're actually saying "people are just happy to use whatever CD or DVD player they have laying around". That might be fair enough, but there used to be people who wanted the direct I2S or an unblemished SPDIF output on their transports. Don't they exist anymore? Has the passion for that just disappeared? It doesn't seem to have from what I see on the DAC projects.

I think that was my original question if I'm honest.
 
- Longevity - an entire replacement mech is less than 20 quid, a laser about 10 quid. Meh. 2 pints these days.
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We cannot afford this lifestyle any more.
We need to get back to consumerism,
where maintenance and repair
produce jobs and not fast product cycles.
Nowadays you toss a whole transport and more often player.
No problem for me as long as they would be 100% recycled
or at least the consumer digs the rare earth
with his own hands. But no one does, so...

Back in the eighties fyou could even replace
the laserdiode in some Pioneer and Yamaha players...

The BU-1 has no mechanical parts prone to wear, a 3mm axis
for the brushless dismotor that can be disassembled for maintenance
bronce bearings that can be replaced and so on...
 
rfbrw said:
Salar, I think your time would be better served building a time machine.
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It sounds like that is what he is doing haha. That mech hasn't been in production for over 20 years and no currently available electronics will drive that type of linear head motor, however elegant it might be.

I think he also needs to learn the difference between a transport and a mech. I've been quite enamoured by some of the other messages I've received. On Semi were very supportive.
 
It sounds like that is what he is doing haha. That mech hasn't been in production for over 20 years and no currently available electronics will drive that type of linear head motor, however elegant it might be.

I think he also needs to learn the difference between a transport and a mech. I've been quite enamoured by some of the other messages I've received. On Semi were very supportive.
Click to expand...

You can also talk to me directly and should read more carefully. The mech is already there, live and as CAD-Data. What you also do not dig:
The whole electronics around a mech is to grab signal and feed it
into a clocked a servo system to gain data for tracking and disc speed.
This is forty years old technology....
Get yourself a CDP-103 or CDP-101 Servive manual and tell me that besides the controller
the electronics cannot be redesigned using off the shelf parts from digikey...
 
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percival007 said:
All the non-CD Players I have listened to don't sound anywhere near as good as a dedicated CD Player, playing CD's.
Modern CD Players using DVD Mechanisms also, to me don't sound as good as a dedicated CD Player.
Click to expand...

How can that be?
The DAC chip and the clock, I would say.
Then rip bit-perfectly with any cheap PC CD reader, and use a good (buffered) USB DAC.
 
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